Solitary Landscape - Solitary Bees as a Design Parameter for Landscape Design by Linnea Storgaard

solitary landscape Solitary Bees as A Design Parameter for Landscape Design

Acknowledgement A heartfelt thank you

To Habeetats for inspiring me to learn about solitary bees, for taking me on board and sharing their knowledge and passion for this subject with me. To Hjalte Ro-Poulsen for indispensable knowledge about solitary bees and for helping me identify species. To Mona Chor Bjørn for great academic guidance and supervision throughut the process, as well as indispensable knowledge about botanics. To fellow students Alida, Helena and Gerd for sharing thoughts, breaks and lunches in the sun. To my parents for seeding my curiousity for all things nature. To Ida, for her compassion. To Malthe, for his advice and motivation.

Abstract A fly-over of this thesis

This thesis uses solitary bees as the base for exploring alternative design parameters in the field of landscape design. The global issue of the biodiversity crisis is often reduced to a simplified agenda of “creating” more biodiversity, and biodiversity as a term is increasingly being used in abundance in urban planning and landscape design projects. This thesis unfolds the relation between landscape design and solitary bees to deepen the understanding of the processes and systems within terrestrial biodiversity. This is done to create a base for applicable design principles for sustaining and increasidng biodiversity through landscape design. The thesis presents knowledge about solitary bee biology and plant biology and connects it to landscape design practice. An interdisciplinary method for site analysis is presented and examplified through the site of Grøndalsparken in Frederiksberg.

This culminates in six design principles, applied to Grøndalsparken and shown in a proposed landscape design and strategy. The proposal showcases site-specific plantcommunities and specific design interventions that could sustain the solitary bees on site and attract new species. The thesis reflects on how solitary bee biology can inform design parameters and decisions, as well as how a design can become a platform for engagement and information about botanics and wild bees. Finally the thesis concludes that solitary bees as a design parameter can influence urban planning and design to become more attentive to detail and make informed decisions to mitigate biodiversity loss, as well as to work with strengthening the interdisciplinary cooperation between different fields of science.

6 All illustrations are my own unless otherwise stated.

30 ECTS Master Thesis written by Eva Linnea Storgaard / CZH242 Throughout 01.02.2022 - 31.05.2022

MSc Landscape Architecture / Urban Design Department of Geosciences and Natural Resource Management, University of Copenhagen

Literature generously funded by Gartner E.A. Jantzen Herboms Bog-legat

Thesis supervised by Mona Chor Bjørn & Hjalte Ro-Poulsen

Table of contents

Motivation

10 13

Problem statement Research questions Thesis reader’s guide

Part zero_introduction

Biodiversity in context

Part one_metamorphosis

A bee trapped in amber Solitary bees Choosing bee species to represent diversity Choosing plants to sustain solitary bees Example study

Part two_translation

64 70

Interdisciplinary method development Site introduction Site mapping and analysis

Part three_creation

116

Design principles Solitary landscape design in Grøndalsparken Lysningen / The Clearing Activating the swale Engen / The Meadow

124

Part four_reflection

126

Solitary bees influencing urban design Conclusion

28 42 50

98 102 114

130 132 170

Lexicon_the bees of solitary landscape References

Motivation

A challenge

Zooming in on solitary bees

When I began the process of writing my thesis, it became clear to me that I wanted to challenge myself as well as my reader. That meant working with a subject outside the more “traditional” scope of urban design. It also meant working with a subject that was new to me, and a subject that would broaden and deepen my knowledge within a scientific field. A steep learning curve. I knew I wanted it to revolve around biodiversity in landscape design. I knew I wanted it to draw a little outside the lines of the norms of landscape architecture. I knew nothing about solitary bees.

The field of biodiversity is broad and complex, and so one relation within it became the starting point for me to deepen my understanding of what biodiversity can mean; the relation between pollinators and plants. Specifically bees and plants, the co-evolutionary pair that so much plant and animal diversity depend on.

An interdisciplinary spill-over I seem to always in some way spill over from one field of science to another, partly because of an interdisciplinary background within the fields of urban design, sustainable development, environmental planning and landscape design. Partly because I believe the fields are inevitably intertwined and need a flowing translation between each other. This thesis is no exception. This thesis dances with Biology; botanics, bees and ecology, Urban design; analysis, planning and strategy, and Landscape Design; materiality, spatiality and aesthetics.

To me, solitary bees and their interconnectedness with flowering plants represent a small part of the complexity that biodiversity and preserving it holds. I hope that this thesis can spark curiosity and deepen the understanding of biodiversity within the field of landscape design. I hope the solitary bees can fascinate the reader as they did me, and that they will prove worthy of preservation in their own right as fascinating, intelligent creatures and not only in the light of what service they can provide for humans.

problem

statement

How does landscape design unfold when solitary bees become the primary client for a design? And how can solitary bees bring new perspective on increasing urban biodiversity through landscape architecture?

Intent

Research statements

This thesis Solitary Landscape offers a way of designing for biodiversity with a deepened understanding for the complexity solitary bees represent. It should be understood as an interdisciplinary work and in that sense a translation between the field of biology and the field of landscape design.

This thesis seeks

The intent of this thesis is to explore how detailed knowledge of solitary bees, their ecology, behavior and preferences can impact a landscape design, and how the understanding of biodiversity, and bee-diversity, can be deepened within the field of landscape architecture and design. It will develop a framework and design principles which can be applied to landscape design in a Danish urban context and in different scale landscape projects, to support bee-diversity, designing with solitary bees as the main client. The solitary bees become the most important design parameter. I will use Grøndalsparken, a long stretch of green public park along a train track, as my own trial case for the framework and design principles, mapping the site from the solitary bee’s perspective. The park lies just at the border between Frederiksberg and Copenhagen. The site analysis will be focused on mapping the existing landscape, vegetation, possible nesting sites and the basic elements (wind, sun, soil, water). I then explore how the site can be improved; can design elements possibly be added to support existing species, attract new ones etc. I will develop a framework and point to what a solitary bee specific strategy and landscape design could look like.

1. to deepen the knowledge and notion landscape architects have within the field of improving and supporting biodiversity in the urban environment. 2. to explore scientific knowledge about solitary bee ecology as a design parameter for landscape design. 3. to show a design that sees the solitary bees as a primary client for landscape design. 4. to validate an eco-centric design approach to inform design choices.

Thesis reader’s guide I have chosen to divide the thesis into four main parts with each their own focus and intent. Before the four parts comes a part zero, giving the reader an introduction and fly-in to important background knowledge, as well as giving an overview of the scientific context this thesis places itself in. Part zero: introduction

This part gives a broader introduction to the subject of environmental awareness history, biodiversity crisis, entomofauna decline and recent movements within landscape architecture. Part one: metamorphosis

Part three: creation

This first part takes the reader through the thesis subject of solitary bees. Their history and biology are presented and unfolded to create an understanding of solitary bee behavior and needs. The bees and plants chosen for this thesis are presented, and a design example study is shown to explore how knowledge about solitary bees can become design parameters for a landscape design.

Part three explores how this analysis could be applied, presenting design principles for landscapes centered around solitary bees. It showcases how the design principles can be implemented in a sitespecific context, as well as what the principles look like in a landscape design proposal. It explores plantcommunities based on site analysis and solitary bee needs.

Part two: translation

Part four: reflection

This part presents a method to map and explore a site with the knowledge about solitary bees in mind. It takes on the theoretical knowledge and begins to apply it in an analysis of a specific site; Grøndalsparken.

This last part offers perspective and reflects on findings, the framework and the design principles. This part offers an inwards reflection on the thesis, an outwards reflection on its context and a conclusion.

part zero

introduction

“It was a spring with no voices. On the mornings that had once throbbed with the dawn chorus of robins, catbirds, doves, jays, wrens, and scores of other bird voices there was now no sound; only silence lay over the fields and woods and marsh.” - Rachel Carson, author of Silent Spring (Carson, 1962, p.4)

Biodiversity in context

The connection between Landscape Architecture, biodiversity and entomofauna decline

A Silent Spring and environmental awareness The last decades have been a time of growing ecological awareness. Since the 1960’s, the conversation and concern about an ecological shift and prevalent crisis has been evolving, as modern environmentalism was sparked and fueled by biologist and writer Rachel Carson’s book Silent Spring in 1962 (Dunlap, 2008). Carson’s book presented scientific research on how heavy use of insecticides and other harsh chemicals were negatively affecting ecosystems, examplified by the decline in insect numbers trickling down to affect the lifecycle of birds. The book handles a very important and at the time publicly unseen and unspoken of issue in a literary and relatable way that made it a best-seller and later an environmental classic (Dunlap, 2008). Silent Spring put the conversation about environmental issues at the top of political agendas, but it also questioned the common conception of nature and humannature relation (Dunlap, 2008), a relation worth continuously discussing and noticing in the field of landscape design where most work includes working with nature. Carson managed to raise awareness with her interdisciplinary approach to storytelling and biology, and after her early death in 1964 still remained a key voice in the debate on how human actions affect the complex ecological systems on Earth. When there is talk about the current environmental crisis or emergency, it is often broadly considered a crisis of climate change, leaving the crisis of biodiversity loss more in the background (Mori, 2020).

There is broad scientific consensus about the fact that humans affect and alter every single ecological system on Earth, (IPBES, 2019) we are transgressing planetary boundaries (Rockström et al., 2009), and the introduction of the term The Anthropocene Epoch has been introduced as a way of viewing Earths current geological period, meaning that human activities are effectively changing Earths geology (Schwägerl, 2018; Steffen, 2018). Humans are also, interlinked, significantly impacting and effectively driving loss of biodiversity (McIntyre et al., 2008; Sánchez-Bayo and Wyckhuys, 2019; IPCC, 2022; IPBES, 2019). “Biodiversity or biological diversity means the variability among living organisms from all sources including, among other things, terrestrial, marine and other aquatic ecosystems, and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems” (IPCC, 2022, p. 7). At the biodiversity convention in Rio in 1992, 150 governments committed to focus not only on how humans are affected by loss of biodiversity, although that is the main focus, but also how biological diversity holds intrinsic value worth preserving as species diversity is important and every species have their own right to existence (Convention on Biological Diversity, 1992). Loss of biodiversity is highly problematic because it has a cascading effect, affecting a number of complex ecosystems towards tipping points that for example can drive further species extinction, climate changes etc. (IPCC, 2022; IPBES, 2019; SánchezBayo and Wyckhuys, 2019; Hooper and Cardinale et al., 2012). The way landscape designers interact with and think about nature is therefore highly relevant, especially in the urban environments and regarding

urban ecosystems where humans might be perceived as dominating in numbers but are taking part in numerous, active and diverse ecosystems (McIntyre et al., 2008). With the amount of knowledge and research in biology and environmental science available, and in the latest years more research on urban ecology (McIntyre, 2008), there are numerous ways to integrate and implement this knowledge in landscape design.

Landscape Architecture and Design and their relation to the biodiversity crisis Biodiversity is now a popular term widely used within landscape architecture projects, urban planning and municipal urban development strategy (SLA, 2022; Frederiksberg Kommune, 2020; Københavns Kommune, 2022, Green Cities Europe, 2022). This is generally a positive tendency, but biodiversity as a term also becomes in risk of being misunderstood or not fully understood and researched, as it is complex and layered as a field of science. As an example, landscape design elements such as flower meadows are a popular route to go down, when trying to improve biodiversity and enhance aesthetics in urban areas, but little research on “pollinator-friendly” seed mixes and their actual impact and effect is carried out (Hicks et al., 2016). Biodiversity is imminently present in landscape design, and landscape architects therefore have great influence on how it is actively carried out through projects and planning, how it is communicated and taught to the public and how it is generally perceived and understood within the field (Gabianelli et al., 2021). Landscape architects therefore also have momentum and responsibility to work out creative solutions for the emergent biodiversity crisis that the world is currently in.

The global movement ‘Architects Declare: Climate and Biodiversity Emergency’ is one way the private architecture sector is moving towards taking responsibility and making commitments to work towards more sustainable solutions for the future of urban- and landscape design. The movement calls for a paradigmatic shift within the field and lists principles the companies commit to follow. In Denmark 96 offices have signed the commitment (Architects Declare, 2022). The movement is not about measurable goals, but a collective way to voice the emergence and severity of the climate and biodiversity crisis, as well as a philosophy for how architects and landscape architects can work with biodiversity and sustainability. The movement thus is a strong signal worth sending and an important framework to explore, but it can also become hard to grasp the actual action points being made on the grounds of it. Because what does biodiversity look like in a design project, how is it measured and when is it making a difference? “We will seek to: Adopt more regenerative design principles in our studios, with the aim of designing architecture and urbanism that goes beyond the standard of net zero carbon in use.” (Architects Declare, 2022) If I was to explore the ambitious, yet vague, abovementioned commitment, it calls for new ways of thinking within design. New design principles with a holistic approach and a deeper understanding of the complexity of intertwined systems as well as scientific fields. It is not just about designing in a way that gives us net zero carbon emission, but about working with ways of designing for, in my case, biodiversity in experimental ways that challenge the traditional scope of landscape design.

“Since they (solitary bees, red.) are a lot more numerous than honey bees species wise, I think they are super important species to work with. Also for biodiversity. Especially if you think about bees and flowering plants being coevolutionary. And in this sense you could say that they have created the landscape way back from the cretaceous period to now, that has made our life on Earth possible. So that is a hundred million year’s worth of evolution.” - André Amtoft, Appendix A, p. 4

Figure 1. Illustration showing an example of biotic pollination.

Solitary bee (Andrena clarkella) provisioning pollen on willow catkins (Salix caprea). As the bee collects pollen for its offspring, it also plays a crucial role in pollinating this and other plants.

Biodiversity crisis from an insect perspective “It appears that insect declines are substantially greater than those observed in birds or plants over the same time periods (Thomas et al., 2004), and this could trigger wide-ranging cascading effects within several of the world’s ecosystems.” (SánchezBayo and Wyckhuys, 2019, p. 9) Within the biodiversity crisis exists many crucial issues. This thesis revolves around terrestrial biodiversity, biodiversity within flora and entomofauna (insects) and specifically solitary bees. The global decline in entomofauna is critical because a large part of Earths flora is dependent on biotic pollination (living pollinators, see figure 1) (Ollerton et al., 2011) and thus insects play a crucial role in functioning ecosystems world-wide (Sánchez-Bayo and Wyckhuys, 2019). “If wild pollinator declines continue, we run the risk of losing a substantial proportion of the world’s flora.” (Ollerton et al., 2011, p. 323) Wild, and in this equation solitary, bees are a key source of pollination (Rasmussen et al., 2016) both of agricultural crops and general floral pollination securing flowering plant diversity (Ollerton et al., 2011; Sánchez-Bayo and Wyckhuys, 2019; McCune et al., 2020). That bees (and other insects) provide such an important and valuable service for humans has caused a rise in research on the topic (Benton, 2019). This is primarily positive, because bees become part of the political agenda, and the subject gains momentum, as it has in Europe and North America where urban beekeeping has become increasingly popular as an urban practice (McCune et al., 2020). But the dialogue about bee conservation risks

becoming only about what (honey)bees provide for humans, e.g., honey and large-scale agricultural pollination, and not about bees in general having their own right to existence and species diversity. This prompts the importance of not only focusing on honey bees in the urban environment, but also on the lesser-known wild bee species that live and can thrive in urban spaces. Research points to the fact, that domesticated honey bees in the urban environment can have negative effects on wild bee communities (Mallinger et al., 2017). Other research also shows, positively, that managed honey bees and wild bee communities in fact can coexist if there is a focus on establishing and upholding a threshold for the density of honey bee hives, creating a healthy and sustainable balance between the wild bee communities and the managed bees (McCune et al., 2020). It is key for the wild bee survival rate that they have access to abundant floral resources and suitable nesting sites in the urban environment, if they are to balance out the numerous honey bees (McCune et al., 2020). In Denmark, 44% of our bee species are red listed, meaning that they are either endangered, becoming endangered and in the worst case regionally extinct. The red list research also shows that urban areas are the second most used habitat and finding place of red listed bees (Moeslund, 2022), making it apparent that there is potential to support solitary bees in the urban environments they have already found their way and adapted to.

Urban Ecology, Urban Nature and Urban Biodiversity In the latest years, urban environments and their distinct ecology has gained traction as an important field of research, as the urban dwelling areas also offer new and unexpected ecosystems (McIntyre et al., 2008). “(…) an urban area is not simply a human-dominated area.” (McIntyre et al., 2008, p. 50). In the acknowledgement that urban areas are not only inhabited or dominated by humans, but shared by other organisms and actors, and in the light of the biodiversity crisis, movements within the field of urban design, landscape design and planning have emerged. In the field of urban planning, there has been a rising focus on urban nature, a term used in abundance for example in policy documents (Frederiksberg Kommune, 2020; Green Cities Europe, 2022). The term ‘urban nature’ works a bit like a superordinate, holding many different definitions, as for example in the Frederiksberg strategy of urban nature and biodiversity, where urban nature can both mean a single standing tree, ecosystems that exist in the urban context and generally all living organisms in the city (Frederiksberg commune, 2020). The philosophy from urban ecology has notably been woven into the conception now being communicated and carried out in urban and municipal planning in a Danish context, also through national initiatives such as the movement and campaign ‘Vild med vilje’ Purposely Wild and ‘Danmarks vildeste Kommune’ Denmark’s wildest municipality. The campaigns both focus on efforts in the municipal context as well as efforts made by civil society (Ministry of Environment, 2022).

The rising focus on biodiversity also means that the term urban biodiversity is gaining attention (Müller and Werner, 2010). This focus on urban biodiversity arrived some time after the convention on biological diversity in 1992, around the mid 2000’s and focuses on the cities not only as the problem, but also as a solution to the problem (Müller and Werner, 2010). A key potential for urban biodiversity is the fact, that the majority of daily interaction humans have with plants and other living organisms happens in the urban context, and therefore there is an opportunity to affect the discourse, raise public awareness and educate people in their immediate surroundings (Müller and Werner, 2010). The urban environment also has the advantage of not having agricultural production, a big threat to biodiversity and entomofauna (Fischer et al., 2016), and often an abundance in parks and gardens. With the right measures, these many parks and gardens can function as a patchwork of habitats in a city, harboring terrestrial biodiversity that we can and need to sustain and increase through urban planning and ultimately landscape design.

Urban environments as a challenge and potential The urban environment firstly presents itself as a challenge within the field of preserving and increasing biodiversity; rapidly growing cities and predicted continued urbanization, dense urban dwellings and a multitude of grey surfaces, Urban Heat Island Effect etc. But there is also potential in the urban environment (Müller and Werner, 2010) and regarding the conservation of wild bee communities, the urban areas might play an important role (Fischer et al., 2016).

In light of the recent movements within the field of landscape design such as ecological-based design (Ignatieva, 2010) and the role landscape architects have designing in the cross-field with living organisms, there lies a great potential and responsibility in exploring how landscape architects can design with a holistic and inclusive nature philosophy in the center, tapping into the already existing policies. As presented throughout this introduction, research suggests that urban areas have the potential to increase and support biodiversity, as well as urban ecology and biodiversity offers insights into new ecosystems, making it a great opportunity and responsibility within landscape design to fully understand and explore the complexity of it better as well as to present it to people in their everyday environment (Müller and Werner, 2010). This thesis is an analysis, method development and exploration of how a landscape design for solitary bees in the urban environment could look like, and a development of principles applicable to landscape design and urban planning, within the context of a framework specific to Denmark.

Gaps in-between practices There lies an obvious challenge in changing landscape design and urban planning practices, where both time, economics and resources play big parts. But maybe time and resources can become better utilized, if there is a closer relation between different fields of knowledge. “(…)there is a learning gap in how to ‘marry’ ecological knowledge (composition, structure and dynamic peculiarities of plant communities) with design qualities and principles (colour, texture, form, balance, contrast, harmony and variety) of urban planting design.” (Ignatieva, 2010, p. 138)

A well thought out planting design that holds the expert knowledge from say biologists, will also be a design with better odds of thriving and serving the urban ecosystem and biodiversity. Ecological knowledge applied and carried out by designers, will probably be a design with better odds of functioning and integrating well design-wise in the urban space. “(…) if our concern is with maintaining bee diversity independently of the services they provide, then the scope must be extended to a wider range of landscapes and habitats, such as urban and suburban green spaces, brown-field sites, downland, heaths and moors and coastal dunes, which act as refuges for bees and other wildlife.” (Benton, 2019, p. 9) As stated by Benton above, there is a need for creative thinking and a broadened perception of the service urban landscapes are thought and designed to provide. The urban parks are not only serving humans as a recreational space and the brownfield sites are not only serving human needs for waste deposit. These sites also serve as important habitats for bees and other wildlife, and they have reason to improve to become better habitats for multispecies. The solitary bees and their needs are the primary design parameter this thesis builds on, and they are the cornerstone informing the design decisions made. But the solitary bees, and the biology behind them can also be an important gateway to get a deeper understanding of what improving and supporting terrestrial biodiversity can mean and look like in a landscape design and urban planning context.

“I think solitary bees offer an interesting window into pollination and biodiversity that kind of short-circuits the typical need that we (humans, red.) always look for in terms of; Well what does it do for us, you know, what does it give back?” - André Amtoft, founder of Habeetats (Appendix A, p. 3-4)

part one

metamorphosis

A bee trapped in amber

The history of bees and flowering plants

The cretaceous period There has long been wondering in the field of biology, about how and when flowering plants (angiosperms) suddenly diversified rapidly (Van der Kooi and Ollerton, 2020). As new methods and technology to reconstruct evolutionary origins have emerged, there has also been a change in the way bees as a species are understood (Danforth, 2019). The increase in species diversity has been estimated to have happened sometime during the early-mid cretaceous period, dating back to more than a hundred million years ago. The question of when exactly it happened is complex and still discussed, and there is no one answer, as new technology continuously brings new methods to bring forth evidence and data. But there is wide recognition that angiosperms and pollinators one way or another impacted each other, creating a snowballing effect which spiked the diversification process and made flowering plants as well as pollinators develop into multifaceted subspecies. Studies and fossil findings show that co-evolution between flowering plants and especially insect pollinators has transpired, and that bees have played a significant role in the rapid diversification of angiosperms in the cretaceous period (Poinar and Danforth, 2006). This is known because a bee fossil trapped in amber was found in Myanmar, dated to the mid-cretaceous period and believed to be one of the first, primitive bees just before the extensive diversification of flowering plants. Because of bees’ great ability to carry and utilize pollen, nectar and other plant material, as well as their diverse and adaptational behavior, angiosperms and bees have co-evolved and diversified into new species.

Bees as a capable and reliable pollinator likely affected and sped up the process of diversification greatly (Poinar, 2020), and the diversity in flowering plant patterns, colors, shapes and scents strongly suggests a coevolution between pollinators and plants, as flowers have wanted to attract bees to some extent (Benton, 2019). The historic time perspective on how long bees and flowering plants have been co-evolving, sheds light on the diversity each group holds and on their careful and detailed interactions in complex ecosystems. This ancient history of bees and flowering plants is a witness of the deep and complex relationship between the two. A piece of evolutionary history dating back to way before human intervention on Earth.

Burmese bee with pollen trapped in amber, dated to circa 100 million years ago. (Source and copyright: George Poinar)

Solitary bees

Biology, ecology and phenology

Introduction

Life cycle

“The idea of a solitary bee may seem strange to many readers. For most people, bees are almost synonymous with social bee-behavior. The word bee typically conjures up an image of a colony of hundreds (bumble bees) or thousands (honey bees) of workers. (…). In reality, the vast majority of bee species on Earth live solitary lives.” (Danforth, 2019, p. 1)

The life cycle of the solitary bee begins with an egg. The small egg is placed in a nest cell by the female solitary bee, where it evolves through stages of larvae, pupa and finally adult bee (see figure 2) (Benton, 2019).

Solitary bees are fascinating creatures, diverse in behavior, appearance and abilities. The most common conception of a bee is often the one of a honey bee, as cited above from Danforth’s text. The word solitary refers to the bee’s social behavior. In contrast to the social honey and bumble bees living in colonies, the solitary bee is just that – solitary. Its purpose is to collect pollen and build a population for the next generation, and its life is short-lived, but very important (Danforth, 2019; Benton, 2019). There are about 20.000 described bee-species on Earth, and 77.4% of them are solitary (Danforth, 2019). In Denmark we have 292 known and registered bee species, of which 65% are solitary in behavior (Moeslund, 2022; Ro-Poulsen, 2018). Solitary bees thus make up a substantial part of the bees in the world, both in numbers and in species diversity, and they play a vital role in pollinating Earth’s flora (Ollerton et al., 2011; Sánchez-Bayo and Wyckhuys, 2019). The bee population of Denmark consists of six families: Andrenidae, Melittidae, Halictidae, Colletidae, Megachilidae and Apidae.

The bee offspring, called brood, go through a full metamorphosis. The egg is laid in spring/summer depending on which months the species are active on the wings, and the metamorphosis unravels throughout autumn and winter (Danforth, 2019; Benton 2019). Eggs are in most cases placed in the nest according to their sex and with a calculated female to male ratio, in a manner where the female eggs are laid first and thus end up at the back of the nests. The male eggs are laid last and end up in the front, where they will break out before the females to seek out a good forage site and be prepared for mating (Danforth, 2019; Benton, 2019). Most solitary bees create brood cells, meaning that each egg has its own, singular and closed off cell. The female bees construct the brood cells with different techniques and materials, depending on which species they are. In the larvae stage, the brood survive and evolve by feeding on a package left by the female bee, typically made of rolled up pollen and sometimes mixed with nectar and plant essential oils. When the larva has finished the nutrient rich package, it develops into a pupa, and within this pupa the larva transforms into a complete adult bee, continuing in a state of hibernation until the weather proves warm enough for it to break out of the pupa and nest to seek out a forage site (Benton, 2019; Danforth, 2019).

Figure 2. Own illustration interpreted from Frances Fawcett’s in; Danforth, 2019

Pupa Adult Egg L1 L2 L3

Winter Spring Autumn Summer

L4 L5 (Prepupa)

Andrena sp. male, Grøndalsparken, Frederikberg. May 2022

The male bees break through and guide the way for the rest of the brood. They fly out to seek nectar and defend potential foraging sites from competitors such as other males, and then seek out the females as they hatch to mate and secure the next generation. The female bees find a suitable nest site, and they then spend all their time on the wings collecting pollen and constructing the nest and brood cells. They fly back and forth in between nesting site and forage site to collect enough pollen to provision the brood cells and close them off one at a time. How many brood cells a female can produce depends greatly on the floral abundance of the area she is in (Danforth, 2019) underlining the importance of having abundant forage sites near a suitable nesting site. The nest is finally sealed to create a protective wall, and the female bee has completed its life cycle and dies (Benton, 2019).

Flying behavior, orientation and senses Solitary bees are essentially ectothermic and therefore their body temperature varies relating to outside conditions (Danforth, 2019). Their thoracic temperature needs to be between 20-30 degrees Celsius to fly, and their flying ability therefore also relies on external heat, either directly radiating from the sun, or from objects radiating heat (Benton, 2019; Danforth, 2019). This is especially important for bees living in the northern hemisphere, where temperatures can drop and vary a lot. They do have a few different techniques to regulate their body temperature which makes them so called facultative endothermic (Danforth, 2019) as they actively find and make up ways to warm up their muscles. Some solitary bees use a shivering to create

heat and most of them seek warm surfaces such as stones and leaves in the sun to warm up (Benton, 2019; Danforth, 2019), a behavior I have observed during field work in Grøndalsparken throughout spring where solitary bees and bumble bees were attracted to and would sit still for long on the leaves of a sunlit ivy bush. Solitary bees in early spring such as Andrena can also use intra-floral basking to keep warm. The spring flower Narcissus sp. which is often used in parks and gardens is an example of this, where the bee Andrena bicolor has been seen to utilize the tubular shape of the flower head and sit inside it for shelter. When temperatures exceed 30 degrees Celsius, the solitary bees can also need to activate techniques for cooling down. (Danforth, 2019). The average air temperature is key for the bee’s ability to keep muscles warm for foraging and doing the many return travels throughout a day (Benton, 2019). In this way, bees are very sensitive to weather, and their activities can easily be affected by changes in temperature and other changing conditions such as cloud cover, wind or rain.

To find their way to their nests and forage sites, the bees use a technique of scanning the ground in a zig-zag motion which is believed to be a form of orientation flight; “The bees are now understood to process the visual information received during these orientation flights into cognitive maps on different spatial scales. As the bee returns it is able to direct its approach by recognizing gross landscape features, and, as it gets closer, to locate its nest entrance in relation to nearby objects such as stones or plant stems.” (Benton, 2019, p. 69). The bees can also use the sun and their inbuilt clock as a tool for navigation (Benton, 2019). When the bees seek out floral provisioning material, they primarily use their visual senses and as they get closer, they also make use of scent as a complimentary cue (Benton, 2019). The bees have compound eyes which can distinguish between movement, shapes and colors. The spectrum of colors they see is blue, yellow and ultraviolet. Their ultra-violet vision makes flowering plants stand out against a green background such as grass, and detailed floral patterns on leaves that the human eye cannot equally see (see photo on the right) appear clear and mesmerizing (Benton, 2019). The finely tuned sensory apparatus of a bee is complex and clever, and gives the bees abilities to navigate by processing complex visual information. They are also able to memorize and learn, as they repeat their routes again and again (Benton, 2019).

Photo showing a Papaver sp. in UV lighting, resembling the way a bee might experience and register the flower. (Source and copyright: Craig P. Burrows, 2020)

Anthophora plumipes male on break in the sun, Grøndalsparken, Frederiksberg. April 2022

Andrena sp. male on break in the sun Grøndalsparken, Frederikberg. April 2022

Floral preferences and foraging Solitary bees depend on access to flowering plants throughout their flying season. Many species can collect pollen and consume nectar from a broad variety of flowering plants, whereas others are restricted to only utilizing a few or as little as one species of flowering plants. The bees collecting from a broad variety are called generalists or polylectic, and the bees collecting from only few specific plants are called specialists or oligolectic (Benton, 2019; Danforth, 2019). The floral preferences within the different species partly rely on the biological trait that the bees have different tongue-lengths, making bees with long tongues (such as Anthophora) able to reach nectar in flowers with tube or gullet shaped heads e.g. Fabaceae, whereas short-tongued bees (such as Colletes) seek out flowers with a basket-like head e.g. Asteraceae (Benton, 2019). Species with the same tongue-length can also have different floral preferences, as seen in figure 3 on the right. The floral preferences are evidently reflected in how the bees are active during a season. In early spring for example, many ground-nesting species oligolectic to Salicaceae emerge as the willows start blossoming and releasing pollen from their catkins, and in the height of summer where the floral supply is highest, both generalists and specialist of different families and genera are active. Knowledge about which bee species has special needs is important, as it needs to be reflected in the choice of plants for a design that supports bee diversity.

Figure 3. Diagram illustrating how two different species can have the same nesting needs, but have different needs in terms of foraging and lecti to different plant families.

Andrena clarkella

+ On the wings: Mid March - End of May + Oligoletic to Salix sp.

Salicaceae

Nest site Mineral/sandy soil Open landscape Sun exposed

Aquifoliaceae Rosaceae Aceraceae Ranunculaceae

Berberidaceae

Grossulariaceae

Buxaceae

Andrena fulva

+ On the wings: End of March - June + Polylectic

Brassicacea

Fabaceae

Figure 4. Diagram illustrating the concept of flying distances and the bees’ opportunities for nesting and foraging relating to their body size.

Lasioglossum alpibes + small bee with short flying ratio

150 m.

Nest site Mineral/sandy soil or cavities Sloping landscape Sun exposed

150 - 500 m.

Anthophora plumipes + large bee with possibly longer flying ratio

Nesting and habitat The solitary bees’ chores are energy and time consuming, making it key that their nesting site and forage site are not too far apart, as they travel this distance many times during a day. Research has shown that long distances in between habitat and suitable forage sites for solitary bees has had a negative impact on brood production and caused a decline in population numbers (Zurbuchen et al., 2010) and the longer time the nest is left unguarded when the female is foraging, the more vulnerable it is to parasites moving in while the female is away (Benton, 2019; Gathmann and Tscharntke, 2002). Research also suggests that when establishing for example flower strips or other kinds of planned forage sites for solitary bees, the forage site and suitable or known nesting opportunities should not be further apart than a maximum of 150-600 meters (Gathmann and Tscharntke, 2002), and the most common forage range is less than 500 metres (Danforth, 2019). The flying range of solitary bees correlate positively with their body length (see figure 4), and therefore smaller bees will need short distances from forage site to nest site (Hofmann et al., 2020; Danforth, 2019; Gathmann and Tscharntke, 2002). This is crucial to factor in when designing landscapes that cater to solitary bees and with an ambition to sustain and grow a population, as well as to attract a diverse group of species. Sun and shelter from strong winds are also important factors when the bees choose a fitting nest site, as many species prefer south-facing walls, banks, roots, sunlit flat terrain etc. (Benton, 2019), and it is important to think about when designing for solitary bees, especially if designing and constructing a habitat for them.

The bees are vulnerable to parasites and fungiinduced illness in the nests, which can quickly become a problem when constructing habitats for cavity-nesting bees. There are many commercialized insect hotels on the market, but most do not have the option of inspecting for illness or parasites, as well as many insect hotels do not have the right dimensions needed for cavity nesting bees. The company Habeetas developed a nest which can be disassembled and inspected without powertools and has different sized holes offering a variety of options for different bee species or specimen and holes deep enough to fit a whole brood generation with the correct male to female ratio (Amtoft, 2022, Appendix A). This shows that there is a need for attention to detail, when constructing artificial nests for bees. There are some different initiatives to create specific designs for solitary bees in the urban environment, such as bee bricks with ready-made holes in them being integrated in the planning requirement in the UK (Frearson, 2022), but it is a complex matter to create healthy, artificial nests for bees, and such bricks would likely also face issues with maintenance and parasites, without the option of taking out the brick to inspect or clean it. This thesis suggests shifting the focus to include design elements that cater not only to cavity-nesting solitary bees, but also the ground-nesting. This can be done by constructing banks of gravel, suitable for many different ground-nesting species (Buglife, 2020). In landscape architecture and design, working with and understanding soil and terrain is already infiltrated in the practice, making it an opportunity to include designed elements such as gravel banks as part of the landscape design.

Andrena fulva female on break in the sun, Grøndalsparken, Frederiksberg. April 2022

Andrena helvola on break in the sun Grøndalsparken, Frederikberg. April 2022

Choosing bee species to represent diversity

Existing data, phenology and ecology

Criteria and protocol To explore and develop ambitious design principles for solitary bees in landscape design, a qualified selection of different species to represent diversity was made. Representing diversity in this case means both diverse in species, behavior and preferences. The selection of species was made through researching the following three factors: • Existing data on solitary bees found in the urban environment and own sightings • Phenology of the bees • Ecology of the bees To be able to develop and present principles, that in their nature are general and should hold the ability to be applied in different contexts, I have chosen to consider all solitary bee families and then select species within them, both generalists and specialists, that are likely and known to appear in the urban context as well as in a Danish environment. The species were chosen based on data collected in Copenhagen in the bachelor project ‘How wild is Vild Campus’ (Vollmer and Jakobsen, 2016), the master thesis ‘Diversity and composition of pollinators in urban parks and cemeteries’ (Kongerslev, 2020) and the project ‘År 0 monitorering af bier I Københavns byskov, Amager’ (Ro-Poulsen, 2018) with the reservation that these data sets are somehow representative of solitary bees in the urban context in Copenhagen and Frederiksberg, but carried out through different sampling periods, with different methods and in different types of landscapes. The choices of species were qualified and detailed by looking at phenology and ecology (Benton, 2019; SLU, 2022, Bees Wasps and Ants Recording

Society, 2020) and reviewed through the Danish Red List (Aarhus Universitet 2, 2022), the research presented in the article ‘Distribution, phenology and host plants of Danish bees’ (Rasmussen et al., 2016) and the lexicon Taschenlexicon der Wildbienen Mitteleuropas (Scheuchl and Willner, 2016). The following list of species are all representative of solitary bees that appear in urban environments, but they are only a small selection. By choosing these 22 species, I can narrow down what factors are needed to create design principles that cater to both generalists and specialists, and by representing a broad range of genera, the design principles will also be able to cater to more species than just the ones selected here. Many of the species have similarities with each other within their genera, meaning that they have similar preferences. The list of species (see figure 5 and 6) should be seen as a tool to understand each species and use that detailed knowledge to create applicable design principles for solitary bees in landscape design.

Visual lexicon I have chosen to collect and communicate more detailed knowledge on each bee species, as well as illustrate them in greater detail, and place this information in a visual lexicon at the end of the thesis. This can be used as a reference work to get a better understanding of each species, its behavior and needs. It can also be used as a tool for recognition and fascination of the bees. The visual lexicon can be found on pages; 132-169.

List of species Family Andrenidae // Andrena haemorrhoa Andrena tibialis Andrena fulva Andrena carantonica Andrena helvola Andrena clarkella Family Colletidae // Colletes similis Colletes daviesanus Hylaeus communis Family Melittidae // Melitta leporina Macropis europaea Family Halictidae // Lasioglossum albipes Lasioglossum calceatum Lasioglossum morio Halictus tumulorum Family Megachilidae // Megachile willughbiella Osmia bicornis Chelostoma rapunculi Chelostoma florisomne Anthidium manicatum Family Apidae // Anthophora plumipes Anthophora quadrimaculata

Andrena haemorrhoa

Andrena tibialis

Andrena fulva

Andrena carantonica

Andrena helvola

Andrena clarkella

Colletes similis

Colletes daviesanus

Hylaeus communis

Melitta leporina

Macropis europaea

Figure 5. Illustrations showing the 22 solitary bee species chosen for the framework.

Lasioglossum albipes

Lasioglossum calceatum

Lasioglossum morio

Halictus tumulorum

Megachile willughbiella

Osmia bicornis

Chelostoma rapunculi

Chelostoma florisomne

Anthidium manicatum

Anthophora plumipes

Anthophora quadrimaculata

Figure 6. Table showing the characteristics of the 22 solitary bee species chosen for the framework.

Species

Common name ENG/DK

Family

Size

Andrena haemorrhoa

Orange-tailed Mining Bee / Havejordbi

Andrenidae

Medium

Andrena tibialis

Grey-gastered Mining Bee / Lønjordbi

Andrenidae

Large

Andrena fulva

Tawny Mining Bee / Rødpelset jordbi

Andrenidae

Large

Andrena carantonica

Chocolate Mining Bee / Tjørnejordbi

Andrenidae

Large

Andrena helvola

Coppice Mining Bee / Æblejordbi

Andrenidae

Medium

Andrena clarkella

Clarke's Mining Bee / Rødbrystet jordbi

Andrenidae

Medium

Colletes similis

Bare-saddled Colletes / Kurvsilkebi

Colletidae

Medium

Colletes daviesanus

Davies' Colletes / Vægsilkebi

Colletidae

Medium

Hylaeus communis

Common Yellow-face Bee / Havemaskebi

Colletidae

Small

Melitta leporina

Clover Melitta / Lucernebi

Mellitidae

Medium

Macropis europaea

Yellow Loosestrife Bee / Hvidbenet oliebi

Mellitidae

Small

Lasioglossum albipes

Bloomed Furrow Bee / Græslandsmalbi

Halictidae

Small

Lasioglossum calceatum

Common Furrow Bee / Moskussmalbi

Halictidae

Small

Lasioglossum morio

Green Furrow Bee / Metalsmalbi

Halictidae

Small

Halictus tumulorum

Bronze Furrow Bee / Bronzevejbi

Halictidae

Small

Megachile willughbiella

Willughby's Leafcutter Bee / Træboende bladskærerbi

Megachilidae

Large

Osmia bicornis

Red Mason Bee / Rød murerbi

Megachilidae

Medium

Chelostoma rapunculi

Scissor Bee / Stor saksebi

Megachilidae

Medium

Chelostoma florisomne

Large Scissor Bee / Ranunkelsaksebi

Megachilidae

Medium

Anthidium manicatum

Wool Carder Bee / Stor uldbi

Megachilidae

Large

Anthophora plumipes

Hairy-footed Flower Bee / Forårsvægbi

Apidae

Large

Anthophora quadrimaculata

Four-banded Flower Bee / Havevægbi

Apidae

Large

Tongue lenght

Ground nesting

Polylectic

Short

•

March/April - June/July

Polylectic

Short

•

March/April - June

Polylectic

Short

•

March/April - Early June

Polylectic

Short

•

April - July

Polylectic

Short

•

April - July

Oligolectic

Short

•

March - May

Salix oligolecty

Oligolectic

Short

•

July - August/September

Asteraceae oligolecty

Oligolectic

Short

•

June - September

Asteraceae oligolecty

Polylectic

Short

•

May - September/October

Oligolectic

Short

•

June - September

Fabaceae oligolecty

Oligolectic

Short

•

July - September

Lysimachia vulgaris

Polylectic

Short

•

March - September/October

Polylectic

Short

•

March - October

Polylectic

Short

•

Polylectic

Short

•

Polylectic

Long

•

May - August/September

Polylectic

Long

•

March/April - June/July

Oligolectic

Long

•

May - August

Campanula oligolecty

Oligolectic

Long

•

April - June

Ranunculus oligolecty

Polylectic

Long

•

June - August

Uses plant hairs for nesting

Polylectic

Long

•

March - June

Polylectic

Long

•

May - August

Lecti

Cavity nesting

•

On the wings

Notes

March - October March - Early autumn Uses plant leaves for nesting

Figure 7.

Number of active species 20

Figure 8.

Species name A. haemorrhoa A. tibialis A. fulva A. carantonica A. helvola A. clarkella C. similis C. daviesanus H. communis M. leporina M. europaea L. albipes L. calceatum L. morio H. tumulorum M. willughbiella O. bicornis C. rapunculi C. florisomne A. manicatum A. plumbipes A. quadrimaculata March Primary flying period Ocurring flying period

April

May

June

This page illustrates how the 22 species chosen for this thesis are distributed throughout a flying season. The graph (figure 7) visualizes the peak in number of species on the wings in the same time period, with June being the month with the highest peak. The table below (figure 8) shows the flight periods of the specific species. The full line represents their primary flight period, and the dashed line represents the period they may be occuring, but are not as likely.

July

August

September

October

Month

Choosing plants to sustain solitary bees

A varied forage resource throughout a changing season

Criteria and protocol To create a landscape design for solitary bees, choosing the right plants is of great importance. This thesis works with different criteria to support the choice of plant species. The choice of plants is based on the following factors; • Plants native to Denmark • Plants with proven solitary bee interaction • Different plants that provide for different species of solitary bees throughout a whole season (March-October) • Plants of different heights suitable for varying landscape design contexts The thesis works with plant species native to Denmark based on The Danish Red List (Aarhus Universitet 1, 2022) and the document ‘Plantekatalog: Planter, der understøtter biodiversitet’ Plant catalogue: plants that support biodiveristy (Strandberg et al., 2021). The choice of species and the ecological details are further researched and validated through ‘Nordens flora’ lexicon of the Nordic flora (Mossberg, B. and Stenberg, L. 2018), ‘Danmarks flora efter vokseted’ Denmark’s flora by habitat (Giversen et al., 2012) and SLU Artfakta Species facts (SLU, 2022).

Native or non-native In the urban environment, there are many nonnative plants, introduced through time by landscape design (Müller and Werner, 2010). Research on the effects of introduced non-native plants has shown, that they can be the cause of disruption and decline in entomofauna (Marinelli, 2020).

This thesis works with native plants on the grounds of research suggesting, that native plants have a better ability to sustain pollinators, and therefore they aid in increasing biodiversity (Marinelli, 2020). This is partly due to the fact, that delicate ecosystems easily get disrupted by too many interfering actors, such as non-natives, and this can cause a trickledown effect (Marinelli, 2020).

Spontaneous vegetation “It is quite a crucial moment to work with a new philosophical approach of appreciation of ‘weedy’, ‘untidy’, ‘messy’ or ‘meagre’ nature by experience and learning.” (Ignatieva, 2010, p. 139) The visual aesthetic which this thesis suggest through choice of plants and landscape elements, might be different to more traditional garden and landscape design aesthetic. This thesis works with a principle of letting spontaneous vegetation occur, meaning that native plants that already grow on site or during time appear should be preserved and kept. Many of the plants that would spontaneously appear in a site and often are perceived as “weeds” or “unwanted plants” are very important forage sources for solitary bees. These among others count: Aegopodium podagraria Taraxacum sp. Cirsium sp. Alliaria petiolata

Figure 9. Diagram showing the critera for the plant species chosen for the framework.

Diffe rin eights gh

Native p lan t

y ar

bee interac t

n io

Proven soli t

ies sp ec Spec ifi

Figure 10. Table showing the 54 plant species chosen for the framework. The list holds information on what kind of environment each plant thrives in, and can be used to match plants in a fitting plant community for the site in question.

Species

Family

Flowering season

Soil

Achillea millefolium ssp. millefolium L.

Asteraceae

June-October

Meadow

Ajuga reptans L.

Lamiaceae

May-July

Moist

Alchemilla glabra N.

Rosaceae

June-August

Moist

Alliaria petiolata M.

Brassicaceae

April-May

Topsoil/moist

Anthriscus sylvestris L.

Apiaceae

May-July

Nutritious

Anthyllis vulneraria L.

Fabaceae

June-August

Dry

Calluna vulgaris L.

Ericacea

AugustSeptember

Dry, nutrient poor

Campanula rotundifolia L.

Campanulaceae

July-September

Dry-wet sandy or clayey

Centaurea jacea L.

Asteraceae

July-September

Nutritious

Centaurea scabiosa L.

Asteraceae

July-September

Dry, sandy

Cichorium intybus var. intybus L.

Asteraceae

July-September

Nutritious, dry. Sun-exposed

Corydalis cava L.

Fumariaceae

April-June

Chalky, nutritious

Crataegus laevigata P.

Rosaceae

May-June

Moist, nutritious

Crataegus monogyna L.

Rosaceae

May-June

Moist, nutritious

Daucus carota ssp. carota L.

Apiaceae

July-August

Well-drained nutritious

Echium vulgare L.

Boraginaceae

June-July

Dry

Eupatorium cannabinum L.

Asteraceae

July-September

Moist, nutritious

Filipendula vulgaris M.

Rosaceae

May-July

Dry

Geraium sanguineum L.

Geraniacea

June-July

Dry, chalky

Geranium sylvaticum L.

Geraniacea

May-July

Moist, nutritious

Jasione montana L.

Campanulaceae

June-August

Nutrient poor, sandy

Knautia arvensis L.

Dipsacaceae

June-August

Well-drained sandy

Ellenberg value F

Ellenberg value N

4+5

5+4

6+7

Type

Height

Color

Perennial herb

20-70 cm.

White or rose

6+5

Perennial herb

15-60 cm.

Dark blue

6+6

4 +4

Perennial herb

20-60 cm.

Green and yellow

5+6

9+8

Perennial herb

30-100 cm.

White

5+5

8+7

Perennial herb

50-150 cm.

White

3+4

2+2

Perennial herb

15-50 cm.

Yellow, orange, red

1+2

Bush

up to 60 cm.

Lilac

2 +2

Perennial herb

10-50 cm.

Lilac

missing

Perennial herb

30-80 cm.

Violet

3+3

4+3

Perennial herb

30-100 cm.

Violet

4+4

5+5

Perennial herb

30-100 cm.

Blue

missing

Perennial herb

10-30 cm.

Purpur

5+5

Bush/tree

1-6 m.

White

4+5

4+6

Bush/tree

1-6 m.

White

4+4

4+3

Perennial herb

30-80 cm.

White

4+4

Perennial herb

20-90 cm.

Blue and violet

7+8

8 + 7+

Perennial herb

50-150 cm.

Lilac, rose

3+4

2+2

Perennial herb

20-50 cm.

White

3+4

3+3

Herb

15-50 cm.

Purpur

6+5

7+5

Herb

15-80 cm

Lilac

3+4

2+2

Perennial herb

10-35 cm.

Blue

4+3

4+4

Perennial herb

30-80 cm.

Lilac

Notes Viable in many different types of soil.

Tolerant and viable.

Low level PH soil

Tolerant and viable

Photo

Species

Family

Flowering season

Soil

Lamium purpureum L.

Lamiaceae

April-October

Nutritious, sandy or clayey

Leucanthemum vulgare Lam.

Asteraceae

June-July

Light, open

Lysimachia vulgaris L.

Myrsinaceae

June-August

Moist, nutritious

Lythrum salicaria L.

Lythraceae

July-August

Moist

Malus sylvestris L.

Rosaceae

May-June

Varied

Mentha aquatica ssp. aquatica L.

Lamiaceae

July-September

Moist or wet

Mentha arvensis L.

Lamiaceae

July-September

Moist to wet

Origanum vulgare L.

Lamiaceae

July-September

Sun-exposed chalky

Pilosella ssp. officinarum L.

Asteraceae

May-July

Dry

Prunella vulgaris L.

Lamiaceae

June-September Moist, open

Prunus avium L.

Rosaceae

May

Moist, nutritious

Prunus cerasifera E.

Rosaceae

April-May

Dry

Prunus spinosa L.

Rosaceae

April-May

Light, open

Pulmonaria obscura D.

Boraginaceae

April-May

Moist

Ranunculus acris ssp. acris

Ranunculaceae

May-September

Moist, nutritious

Ribes nigrum L.

Grossulariaceae

May-June

Moist

Ribes uva-crispa L.

Grossulariaceae

May-June

Well-drained

Rhinantus minor ssp. minor L.

Orobanchaceae

May-July

Open, meadow

Rosa canina ssp. canina L.

Rosaceae

June-July

Light, open

Salix aurita L.

Salicaceae

May-June

Moist, sandy

Salix caprea ssp. caprea L.

Salicaceae

March-May

Varied

Solidago virgaurea ssp. virgaurea L.

Asteraceae

July-September

Dry-moist

Ellenberg value F

Ellenberg value N

5+5

Type

Height

Color

Notes

7+7

Annual herb

5-35 cm.

Purpur

4+4

3+4

Perennial herb

20-70 cm.

White and yellow

8+9

Perennial herb

50-160 cm.

Yellow

8+9

Perennial herb

50-100 cm

Purple

5+5

5+6

Fruit bearing tree

2-8 m.

White and rose

9+8

5+5

Perennial herb

20-70 cm.

Lilac

Aromatic herb, water tolerant

7+7

Perennial herb

10-40 cm.

Lilac

Aromatic herb, water tolerant

3+4

Perennial herb

20-80 cm.

Red/Violet, tall, bushy

4+4

2+2

Perennial herb

5-20 cm.

Yellow

A. manicatum utilizes plant hairs

5+5

Perennial herb

5-25 cm.

Purple

Viable and adaptable

5+5

5+6

Tree

5-20 m.

White

Bush/tree

1-8 m.

White

4+5

Bush/tree

1-4 m.

White

6+6

7+7

Perennial herb

10-30 cm.

Violet, purpur

6+6

Perennial herb

20-70 cm.

Yellow

9+9

5+6

Fruit bearing bush

1-1,5 m.

Red/green flowers

6+6

Fruit bearing bush

0,5-1,5 m.

Red/green flowers

Annual herb

10-30 cm.

Light yellow

Bush

Up to 3 m.

Light rose

8+8

3+3

Bush/Tree

0,5-3 m.

White and yellow

6+7

7 + 7+

Bush/tree

3-15 m.

White and yellow

5+5

4+3

Perennial herb

25-100 cm.

Yellow

Macropis europaea is oligolectic

Aromatic herb

Water tolerant

Photo

Species

Family

Flowering season

Soil

Sorbus aucuparia ssp. aucuparia L.

Rosaceae

May-July

Dry-moist, nutritious

Stachys palustris L.

Lamiaceae

July-September

Moist, nutritious

Succisa pratensis L.

Dipsacaceae

AugustSeptember

Moist, nutrient poor

Tanacetum vulgare L.

Asteraceae

July-September

Sandy or humus

Thymus pulegioides L.

Lamiaceae

July-August

Well-drained nutritious

Torilis japonica DC.

Apiaceae

June-July

Open, nutritious

Trifilium repens L.

Fabaceae

June-September Open, moist

Verbascum densiflorum L.

Scrophulariales

July-September

Dry, nutritious

Verbascum thapsus L.

Scrophulariales

July-September

Well-drained, sun exposed

Veronica spicata L.

Scrophulariales

July-August

Moist, nutritious

Ellenberg value F

Ellenberg value N

7+8

6+7

7+7

Type

Height

Color

Notes

Tree/bush

5-15 m.

White

Perennial herb

20-110 cm.

Purple

2+2

Perennial herb

25-60 cm.

Violet

5+6

5+7

Perennial herb

30-150 sm.

Yellow

4+4

1+2

Perennial herb

5-25 cm.

Red/Violet , dense, bushy

5+5

8+7

Herb

30-90 cm.

White/rose

5+5

6+6

Perennial herb

10-30 cm.

White

Can capture nitrogen in soil

missing

Perennial herb (2 years)

30-180 cm.

Yellow

A. manicatum utilizes plant hairs

4+4

7+5

Perennial herb (2 years)

30-150 cm.

Yellow

A. manicatum utilizes plant hairs

3+3

2+2

Perennial herb

25-100 cm.

Blue

Photo

Aromatic herb

Nota bene This list should not be seen as a list to pick and choose from randomly, but a suggestion to which plants can support a varied population of solitary bees. To create a planting design, factors such as natural habitat, growth conditions and plant species interrelated dynamics need to be taken into account.

Example study

AV Miljø x Habeetats / Avedøre Holme brownfield industrial area

Site To get an understanding of what designing for solitary bees can mean and look like, I contacted the company Habeetats. They design nests for solitary bees, specifically catering to mason bees (Osmia) and leafcutter bees (Megachile) which are both cavity nesting species that seek out existing structures which fit their body diameter, to build their nests in. The Habeetats nests provide attractive habitat for Osmia and Megachile, particularly in more open and windblown landscapes where there are not as many structures for these bees that they can utilize for nesting. Placed in the industrial area of Avedøre Holme, the recycling station and landfill site AV Miljø with its vast and uncontrolled vegetation has become a site of potential for solitary bee conservation. The landscape is made up of deposit, which has created steep slopes and a hilly terrain. The site is full of spontaneous vegetation, and at a particular South-west facing sunlit and initially sheltered spot, Habeetats have put up three nests for solitary bees as well as sewn and planted a range of specific herbs and plants to create a varied foraging site. The purpose of the project is to monitor the bees and their preferences for nesting in different colored nests that represent different temperature scenarios, corresponding to the temperature shifts caused by climate change. The three nests and an information sign clearly and visually communicate the project, to spark curiosity and tell the story of solitary bees and their environment to visitors. The site is thought as a learning environment, with room for different levels of interest, exploration and engagement.

I found that the landscape was varied and interesting visually even in dormant state in January, where tall plant stems and shrubs offer structure for the visual composition of the place. There are narrow, winding paths, created by cutting the tall vegetation short only where needed.

Plants and vegetation List of added plants: Salvia officinalis Ajuga reptans Symphytum grandiflorum Corydalis sp. Lamium album Hieracium sp. Ranunculus sp. Astragulus sp. Campanula patula Lotus corniculatus Salvia pratensis Centaurea cyanus Origanum vulgare Leucanthemum vulgare Calluna vulgaris Lucerne sp. Stachys byzantine Papaver sp. Prunella vulgaris Teucrium chamaedrys Lamium maculatum Lavandula sp. Thymus sp. Echium vulgare Geranaium sylvaticum At the site there are also James Grieve apple, oak tree and willow which serve as a source of pollen.

Avedøre Holme, AV Miljø / Site registration, February 2022

Habeetats x AV Miljø Ingemann nests for cavity nesting solitary bees, testing different nest temperatures with albedo effect and digital data monitoring. Site visit in February, 2022.

There are numerous spontaneous plants brought to the site with building deposit over time, and this “un-designed” vegetation can add to the overall capacity of the site to support solitary bees of different kinds.

Reflections AV Miljø x Habeetats is an example of how to activate the peri-urban areas and brownfield environments to create intentional value and contribute to a higher diversity of plants and animal species, as well as communicate to and engage with the public. The project has a great vision as well as a well-thought-out design for the cavity-nesting solitary bees but is also quite narrow as the focus mainly lies on supporting two species of generalist bees. Regarding the plant design, it could potentially hold a greater focus on for example using only native plants, or map which plants ended up thriving in the site to get an understanding of the current plant community that developed over the three years and which solitary bee species it currently caters to. The design could potentially be supporting a good amount of ground-nesting species, as AV Miljø is evidently a site that could hold many different ground-nesting species in the sloping terrain with exposed soil, and observing which species utilize the plant community would be highly relevant, to understand if many different species can thrive in a site like this if additional forage opportunities are added. The project is very interesting and does well in its’ character of experiment and exploration. The project builds on deep knowledge about cavitynesting bees’ nests as well as a broader knowledge about plants for solitary bees, but it also experiments

with different temperatures in the nest, as well as how to create a designed landscape catering to solitary bees. Monitoring the bees and following the project through the seasons makes it a great site for trial and error, research, exploring and experimenting with how such a design develops over time and if it works as intended. The context of AV Miljø makes it an interesting and poetic cross-field - the industrial waste site becomes a potential site for propagating solitary bees and flowering plants, increasing biodiversity as well as a place for learning and communicating the issue of pollinators under pressure. The project creates grounds for exploration and experiments, as well as it is an inspirational pioneerproject showing a way to create a landscape design with solitary bees as the primary client, and with a deeper knowledge about their specific needs in focus, with the extra layer of engaging the surroundings.

“A large part of the problem and the solution is the lack of communication and understanding between ecologists and the professions currently responsible for designing and maintaining the urban environment, including (inter alia) planners, architects, civil engineers, sociologists, horticulturalists and foresters.” - Müller et al., 2010, p. 610

part two

translation

Biology

Landscape Design

Interdisciplinary method development Biology x Landscape Design

Building bridges The departure point for working with a site in this thesis is to look at it from the perspective of the solitary bees, to understand the correlation between flowering plants and pollinators, as well as to explore the complexity of working with supporting and assisting biodiversity. The methods presented in this part of the thesis therefore is a way of merging the knowledge about biology into a comprehensive framework for landscape architects to work with a deeper understanding and more detailed knowledge about interrelations between plants and pollinators when they create landscape and planting designs. It is an attempt in bridging gaps between the field of biology and the field of landscape design, and a way to challenge existing practices in landscape design which often-times prioritizes the human needs and experience before other considerations, leading to little focus on the detail of for example ecosystem processes. In the process of collecting and understanding the knowledge about solitary bees and flowering plants, the biology became a tool to better understand the natural flux and processes landscape design evidently works and interferes with. Zooming in on the behavior and needs of these important organisms gives the thesis a framework for design that unlocks interesting perspectives of landscape design practices.

Bringing this into the analysis means taking notice of the small details in the existing landscape, as well as understanding both challenges and potentials of a site in the perspective of creating a design supporting and creating bee- and biodiversity. This becomes an interdisciplinary method and translation between the field of science and the field of design – A crossfield where landscape architects already are present, but where there is a need for better communication (Müller et al., 2010). Analyzing a site from the perspective of the solitary bees and their needs, calls for attention to detail. It is important to get an understanding of the context the site is in as well as the existing conditions possibly catering to the bees. For example, a sunexposed sloping train terrain can be an important factor worth of preservation, or plants usually considered as “weeds” can be important for the bees and the ecosystem they are part of. In the analysis, one must keep an open mind and flip the usual way of analyzing human flow, recreational activities etc. and instead put themselves in the place of say; a Hairy-footed flower bee.

Site introduction

Grøndalsparken, Frederiksberg

Site boundaries and context

Grøndalen

Grøndalsparken is a 3-kilometer-long public park that stretches as a green strip all the way from Damhussøen in the South-west and to Nordvest in the North-east. The park is cut into different fragments by infrastructure, and the shape of the park is defined by how it follows the train tracks that run through the area.

South of the chosen site in a big terrain depression, the Danish landscape architects Opland have done an extensive re-design of the park to make it able of handling the large amounts of rainwater occurring during heavy rain and evermore frequent stormwater events. The project called ‘Grøndalen’ consists of a big skate bowl detention basin, a retention basin pond and seating steps in an amphitheater like formation. The main goal of the project is stormwater management, but it also holds wildflower meadows and many different perennials and bushes along the path and in the sloping terrain towards C.F. Richs Vej, which can aid in supporting the overall biodiversity of the park. This also means that bees with a longer flying range would be able to utilize the landscape South of the site boundaries of this thesis.

I will use a segment of the park as an example of an existing public green area, with the potential to support solitary bee diversity and ultimately biodiversity. This thesis works with the approximately 900-meter-long part of Grøndalsparken that lies in Frederiksberg between Godthåbsvej and C.F. Richs Vej, East of the train-tracks. I have chosen these site boundaries, because Frederiksberg municipality has worked with biodiversity projects, e.g. wildflower meadows, in this segment of the park, and I thought it was interesting to tap into an already existing incentive and political will to increase biodiversity in an urban planning context. The site boundaries are also defined by the physical barriers which shape the park segment, such as roads and train-tracks, to give the site a fitting and pragmatic scope. This thesis proposes and explores within these site boundaries, as landscape design proposals traditionally do. But it should be mentioned that solitary bees of course do not read site boundaries in the same way humans do, and their physical barriers and boundaries are experienced different to mine. They will transgress these boundaries as they see fit.

Site history The name of the park can be loosely translated to ‘The green valley park’ and it reflects the terrain shaped by the creek that used to run through it. The creek now runs in tubes underneath the train tracks, and rainwater is handled through a swale in the western side of the park. The creek has created a sloping terrain in the middle of the park, as well as the train infrastructure has created long, humanly inaccessible hillsides along the train tracks. The park is popular as a recreational area for citizens to do exercise, walk and play. Grøndalsparken was originally designed in 192933 by Valdemar Fischer-Hansen who was the city gardener for Copenhagen at the time (Nicolaisen, 2011), and the design has mostly been kept throughout the last near century. It primarily consists of open, kept grass lawns,

Figure 11. Context map 1: 10.000 (Ortophoto source: SDFE )

God thåb svej

rg be s k ri e de r F n arke p s l a ønd Gr

chs V ej

G rø

n dalen

by O pla n d

Grøndalsparken, aerial photo from 1930’s (Source: The Danish Royal Library) N

alternating between solitary trees, groups of trees and bushes, bulbous plants and hedges drawing up the edges of the site. These are all traditional landscape elements for this period in Western landscape design where the garden park style established by Olmstedt was still prevalent in the realm of public parks (Ignatieva, 2010). The park has many spatial qualities for the human user, with a broad variety of trees and bushes creating many different recreational zones for relaxation, exercise and walking on the paved path and smaller desire paths along the sloping terrain. These different vegetative elements in the park very likely also serve as habitat and source of life for a varied animal, insect and plant life. The park became a protected landscape area in 2010 with the purpose of securing the space as a recreational public park, protecting it from development but also to improve or at least maintain the existing biological, recreational and landscape values. A main purpose of the conservation is also to support and increase biodiversity in the park (Danmarks Naturfredningsforening/The Danish Society for Nature conservation, 2022). With Grøndalsparken as the example site to apply design principles, I will argue, that the aim to increase and uphold biodiversity in the park weighs heavier than the criteria in the conservation policy to not make changes in the existing vegetation or terrain.

Frederiksberg municipal biodiversity policy With the growing focus on biodiversity decline and biodiversity in urban nature, Frederiksberg municipality has developed a political strategy to support biodiversity within the municipality. For the years 2021-2025, 15.8 million DKK has been put aside to support biodiversity and urban nature at Frederiksberg (Frederiksberg Kommune, 2022). Frederiksberg municipality has an extensive political strategy for biodiversity, aiming to both strengthen their identity as a green city, give citizens opportunities to maintain a healthy lifestyle in the urban environment and spark inspiration for more individual and communal green initiatives. The aim is also to support livable habitats for birds, insect- and animal species, to increase biodiversity, use more native vegetation and contribute to aesthetic and visual experiences (Frederiksberg Kommune, 2020). The strategy focuses on many different aspects of what green spaces and urban nature can give to the citizens, how they represent the brand of the municipality as well as how they can be used as a measure to mitigate climate change caused phenomena such as CO2-emission and Urban Heat Island Effect. The strategy in this sense both focuses on the welfare and wellbeing of the citizens, but also claims to focus on plant and animal life.

Site mapping and analysis

Collecting knowledge and mapping potentials

A baseline analysis The method this thesis develops and uses, is a mapping method focused on noticing the important factors to create a functional landscape design for sustaining and attracting different species of solitary bees. This can both be in addition to an already existing one or in a completely new design.

Analysis factors • Landscape structure • Vegetation typology • Wind • Sunlight • Vegetation • Soil Landscape structure

The first step is noticing which landscape structures dominate and exists in the site. This means looking at the existing topography as well as the character of the landscape, both from above through maps and GIS information, but also most importantly by experience on site. This factor means a lot for establishing new vegetation, changing the terrain, making additions and design suggestions. Where does the water go? How is the landscape structured in regards of existing conditions suitable for nesting solitary bees and where could adjustments be made for the landscape to better cater to the solitary bees? Vegetation typology

Secondly, it is important to notice what kind of vegetation typology exists on site, if any, to understand the landscape base and starting point. This means mapping if the site is full of bushes, trees, grasses, herbs etc. Note if the site holds only

one type of vegetation or is more diverse. Look to the context of the site, if there are vegetative areas close-by or not,what kind of vegetation typology the possibly adjacent green areas hold and how far away they are. Sunlight/Wind/Vegetation/Soil

Next is zooming in, understanding the elements on site; When the sunlight hits which part of the site, what kind of wind conditions exists, which plant species exist there, and which kind of soil is on the site. The sunlight is important for both the nesting opportunities and the flora, both the existing and the ones added to the site. Wind is important for the bees’ nesting and flying behavior. The existing plants are important for the forage opportunities as well as which bees are already present, and what plants can thrive there. The soil types are important for nesting opportunities as well as the existing and added flora.

Summary These are all factors that can greatly differ depending on the site in matter, and therefore this initial mapping analysis will turn into diverse points of departure for a possible design for solitary bees in different context and sites, and an analysis can work as a baseline for which primary action points to take and how to design and plan further.

Landscape structure

Vegetation typology

Wind

Sunlight

Vegetation

Soil

Figure 11. The analysis of Grøndalsparken takes its starting point a walk-through from the southern part of the site, under C.F. Richs Vej [1] and continues North-east towards Godthåbsvej [2]. Map based on latest ortophoto showing the full park segment and route of the analysis, as well as a scale circle with a 80 m. radius to get an impression of the distances on site.

(Ortophoto source: SDFE)

Grøndalsparken looking Northwards at the bridge (C.F. Richs Vej) marking the site “entry”. April, evening sun

Landscape structure The site’s topographical character as former riverbed terrain is the first immediate structure to note, as the sloping terrain makes for a good existing base for many solitary bee species. When walking from South to North-east, there is a steep South-west facing soil bank dropping from 16.5 meters to 13.5 meters. Throughout this analysis, it will be referred to as ‘the bank’ (see figure 12). The bank is an important structural feature because it acts as a great nesting site for many groundnesting species of solitary bees, such as A. fulva, A. haemorrhoa, A. clarkella, C. similis, and A. plumipes. The bank is hidden away behind bushes and tall trees, making it less accessible to humans, which is favorable for the bees already living there as they can remain undisturbed. The bank is also relatively bare without too much vegetation and made up of loose soil which are both good conditions for the ground-nesting bees’ excavation practices. The landscape opposite the bank drops from 15.50 meters to 13.50, in a less steep manner. This slope consists of more hard-pressed soil and is more shaded, making it a less attractive nesting spot. In the middle of the site runs a recreational gravelpaved path for humans. Along the path, a swale has been dug to lead rainwater from the low point in Grøndalen (by Opland) through the terrain differences and into the pipes that run underneath the train tracks. Further North on site, the terrain flattens, widens and becomes more open with visual contact to both neighboring villas to the East and the train tracks to the West.

This change in the landscape creates opportunities for the ground-nesting bees that prefer an open and flat nesting ground, such as L. morio, L. albipes, L. calceatum and H. tumulorum. It does pose a challenge for some of the bigger cavity nesting bees such as O. bicornis, M. willughbiella and A. manicatum dependent on larger 6-10 mm diameter cavities, as there is a longer distance from fitting nesting sites to possible forage sites, but these larger bees can also fly longer distances.

The path in the middle of the site, showing the topography of the sloping riverbed terrain. The photo is taken in April 2022, facing North with the South-west facing bank on the right-hand side.

Figure 12. Analysis notations of the landscape structure and topography on site.

The North-eastern part of the site where the topography flattens out and grass lawns, big trees and patches with bulbous flowers dominate. The photo is taken in May at noon, facing North.

79 N

Figure 13. Analysis notations of the vegetation typologies on site.

Vegetation typology The main vegetation typologies on site are tree groups, single standing trees, bramble thickets, bushes, grass lawn, bulbous plants and flower meadow. Many of the bushes and trees are spring flowering. When walking from South to North-east, the vegetation typology on site changes a lot. In the southern end, where the site is narrow and varied in topography, the site is edged by dense bushes and groups of trees almost reaching each other. The Prunus cerasifera trees and bushes dominate in early spring, with their white flowers and dense treetops. The vegetation edging the sloping terrain almost creates a canopy, illustrating the closeness from on side to the other. It also seems like there is room for spontaneous vegetation, taller grasses and herbs as well as a there are relatively little garden maintenance practices carried out. Moving further North, the train tracks and a thicket of bushes make up the western edge and villa garden hedges make up the edge to the East. As the terrain drops, the path leads onto a wide, maintained grass lawn with single standing trees and few spread out, organically shaped flower patches in the lawn with bulbous plants such as tulips and daffodils. These can be utilized as a shelter for bees during cold spells (Danforth, 2019) but have little value as forage resource. Few of the trees and bushes are blossoming. The site lies adjacent to the part of Grøndalsparken in Copenhagen, just West of the train-tracks ( see figure 13). It also lies in close proximity to the many private gardens to the East, where a variety of native and non-native plants might also provide solitary bees with pollen and nectar throughout the season.

The path in the middle of the site, showing the topography of the sloping riverbed terrain and the vegetation almost creating a canopy above. The photo is taken in May at noon, facing South.

83 N

Wind conditions The site is quite sheltered from wind because of its topography, making it ideal for the bees being on their wings even during windier days. The eastern bank is technically exposed to the western wind, the prevalent wind direction in Denmark (Miljøstyrelsen, 2022), but tall trees, bushes and buildings create good shelter. This has great value, as the bees can get more time on the wings to collect pollen, when they are sheltered from strong winds.

Sunlight conditions To get an idea of the sunlight conditions on the site, a sun diagram shows the course of the sun in both winter and summer (see figure 14). The diagram shows, that during spring and summer, the bank gets many hours of sunlight, making it an obvious potential nesting site for ground-nesting solitary bees. In winter, the sun will reach the site much later in the day, but the bank will still have some hours of sun to create some external heat for the hibernating brood. I also spent time on site to understand at what times there is experienced sunlight and warmth. This is both to get an idea of where the sun hits and warms up existing nest and forage sites of the solitary bees that are on the site, and which spots have potential to support and propagate the bees further. The experience in late April was, that in the height of the afternoon the sun hits the bank as well as a lot of the vegetation, making the bees get on the wings to collect nectar, pollen and warm up in the sun. I observed different species of solitary bees (Andrena fulva, Anthophora plumipes, Andrena haemorrhoa, Andrena carantonica), as well as a number of honey bees (Apis mellifera) and several species of bumble bees (Apidae) when it was warm and sunny.

In the North-eastern part of site, sunlight hits the open landscape in morning and at noon, and because of the relatively low housing, the sun reaches the site well in spring when its course on the sky is tall. I did not observe as many bees in this area, though I did spot an Andrena sp. and bumble bees. Sunlight is also an important factor for the growth conditions of the plants being added on site in a potential design, as well as shadow can be important for some plants and for the bees to cool off in summer. The shadow on site is easiest to assess by experiencing the scale of things on site and noting which trees and bushes cast shadows that can affect the growth conditions of the vegetation.

Figure 14. Diagram showing the sunlight conditions on site with a starting point in winter solstice and summer solstice in Denmark. (Data source: SunCalc.com, 2022)

Summer sunset

Summer sunrise

circa 10 PM

circa 4.30 AM

Morning sun

ken r a alsp d n Grø Afternoon sun

Winter sunset

Winter sunrise

circa 3.30 PM

Midday sun

circa 8.30 AM

Vegetation

List of noted vegetation

During this thesis it has only been possible to get a general overview of the different species of plants on site. Through site visits and casual registration throughout March, April and May an overview was made of some of the variety in the park at springtime. I especially took note of existing vegetation important to, and already sustaining, solitary bees and therefore did not notice og identify all vegetation.

Acer platanoides Aegopodium podagraria Alliaria petiolata Crataegus monogyma Crocus sp. Lamium album Lonicera periclymenum Malus domestica Narcissus sp. Primula veris Prunus cerasifera Prunus padus Prunus serrulata Ribes uva-crispa Rubus plicatus Salix caprea Scilla sp. Taraxacum sp. Tussilago farfara Tulipa sp.

The vegetation in the southern part holds numerous Prunus cerasifera bushes and trees, Scilla sp. flowers, and a few Salix caprea trees all blooming in early spring. These are important for the willow specialist bees such as A. clarkella and the solitary bees of early spring such as A. fulva, A. plumipes, O. bicornis, L. calceatum and L. morio. There is also Ribes sp., Rubus sp. and Crataegus sp. on site, that could attract and supply for many solitary species in the flowering season during spring. There are a few Malus sp. trees, many Acer platanoides which can provide pollen for Andrena sp. and then there is an abundance of Taraxacum sp., Aegopodium podagraria and Alliaria petiolata all serving as good pollen provision for many generalist solitary bee species.

Photo registrering details to get an impression of the vegetaion sustaining solitary bees in the site. Grøndalsparken, April & May 2022

Existing Vegetation qualities Throughout the site there is a variety of flowering plants already serving and sustaining a population of pollinators. Many of the plants are intentional and classic for park design, such as Scilla sp., Narcissus sp., Prunus cerasifera, Tulipa sp., Acer platanoides and Prunus serrulata. There is also a variety of native plants, possibly spread spontaneously, that serve as an important source for nectar and pollen. During site registration I found common bumble bee species such as Bombus terrestris and Bombus lapidarius, as well as many specimen of the common honey bee Apis mellifera. I also registered a few different species of solitary bees, as mentioned on page 84. To increase the diversity as well as the total number of solitary bees, there is a need for more abundant foraging opportunities within reach of good nesting sites. There are many qualities in the vegetation in Grøndalsparken, making it a great opportunity to optimize and direct it to cater intentionally to existing solitary bee species on site and attract new species. A potential issue could be the already established and vegetation outcompeting added vegetation.

Soil conditions To assess the existing soil conditions of the site, I use Ellenberg’s general indicators of soil fertility (Aarhus Universitet [3] 2022; Hill, 1999) using the table from Aarhus University which names plants typical for a Danish context (see figure 15). By visually registering which plants grow on the site, it is possible to get an overall idea of the soil conditions without doing a comprehensive soil analysis, as well of an overview of which plants would be viable in the current different environments. It is important to note, that well-functioning plant communities (phytocoenosis) and their ability to thrive on a specific site not only depends on the nutrient value, but also on Ellenberg’s other indicators such as moist, sunlight, shadow, PH value etc. as well as how they interact in dynamics together. This thesis focuses on analysis of a site and applicable design principles. Therefore, I have chosen to focus mainly on the nutrient indicators, as a full indicator analysis would be too time- and resource consuming and take time away from focusing on the solitary bees. In Grøndalsparken, within the site boundaries of this thesis, there is a lot of grass lawn quickly giving away that the soil is nutrient rich, as a thick carpet of grass thrives in and reproduces well in nutrient rich soil. There are big patches of Aegopodium podagraria, (indication number 7), meaning that the soil is richly fertile. Tussilago farfara (indicator value 6) and Alliaria petiolata also grows in the same spot. Aegopodium podagraria generally grows in many half-shaded spots on the site, indicating nutrient rich soil.

Figure 15. Table showing the Ellenberg indicator values for nutrients in soil, as well as the visual indicators, meaning plant species that can indicate nutrient conditions (Latin and Danish names). (Data source: Arhus Universitet [3], 2022)

Indicator value for nutrients (N+NO)

Description

Species ENG/DK

Indicator of extremely infertile sites

Drosera intermedia (Liden soldug), Empetrum nigrum (Revling), Erica tetralix (Klokkelyng), Eriophorum vaginatum (Tue-kæruld), Gentiana pneumonanthe (Klokke-ensian)

Between 1 and 3

Vaccinium uliginosum (Mose-bølle), Viola palustris (Eng-viol), Triglochin palustris (Kær-trehage), Succisa pratensis (Djævelsbid), Potentilla erecta (Tormentil), Carex rostrata (Næb-star)

Indicator of more or less infertile sites

Briza media (Hjertegræs), Comarum palaustre (Kragefod), Epilobium palustre (Kær-dueurt), Equisetum palustre (Kær-padderok), Hydrocotyle vulgaris (Vandnavle), Juncus conglomeratus (Knop-siv)

Between 3 and 5

Stellaria palustre (Kær-fladstjerne), Prunella vulgaris (Alm. brunelle), Lychnis flos-cuculi (Trævlekrone), Juncus effusus (Lyse-siv), Deschampsia cespitosa (Mose-bunke), Equisetum fluviatile (Dynd-padderok)

Indicator of sites of intermediate fertility

Epilobium parviflorum (Dunet dueurt), Carex elata (Stiv star), Holcus lanatus (Fløjlsgræs), Juncus bufonius (Tudse-siv), Lathyrus pratensis (Gul fladbælg)

Between 5 and 7

Rumex crispus (Kruset skræppe), Schoenoplectus lacustris (Sø-kogleaks), Sonchus arvensis (Agersvinemælk), Glyceria fluitans (Manna-sødgræs), Phragmites australis (Tagrør), Iris pseudacorus (Gul iris), Lemna minor (Liden andemad)

Plant often found in richly fertile places

Aegopodium podagraria (Skvalderkål), Anthriscus sylvestris (Vild kørvel), Bidens tripartita (Fliget brøndsel), Ranunculus repens (Lav ranunkel), Elytrigia repens (Almindelig kvik), Geum urbanum (Feber-nellikerod), Phalaris arundinacea (Rørgræs)

Between 7 and 9

Urtica dioica (Stor nælde), Ranunculus sceleratus (Tigger-ranunkel), Heracleum mantegazzianum (Kæmpe-bjørneklo), Glyceria maxima (Høj sødgræs), Galium aparine (Burre-snerre)

Indicator of extremely rich situations, such as cattle resting places or near polluted rivers

Rumex obtusifolius (Buttbladet skræppe), Oxybasis glauca (Blågrøn gåsefod)

Photo registrering details to get an impression of the different spatial qualities, typologies and elements sustaining solitary bees in the site. Grøndalsparken, April & May 2022

Existing soil qualities and issues The site holds some good nesting spots for ground-nesting species. Taller banks, smaller slopes and more flat and open stretches of soil, sunlit at different times during the day, offer different opportunities for differing species. Some of the soil at the highpoints of the riverbed terrain and the rainwater swale is very hard-pressed due to rainwater runoff and sun, making it harder to excavate for some ground-nesting species as well as for the existing vegetation to thrive, though it does also create spots with sparse vegetation which is often a requirement for good nesting spots. On the bank, there is a more loose soil type also rich in bark and old branches, which creates opportunities for many different species to excavate nest corridors.

Summary Through the six-step analysis of the site many potentials have been brough to light. The topography of the park as well as its character as a narrow green spine running through multiple different urban areas, makes it an evidently fitting habitat for cavity-nesting and especially groundnesting solitary bees. With targeted, incision landscape design interventions, the park can better sustain existing solitary bee species, support and propagate a larger population and attract more specialist species to the area. The analysis has also brought forward some issues, mainly that the landscape structure of the Northeastern park segment is more open and has less herbal density as well as fewer flowering trees and bushes, making it a less attractive site for solitary bees needing to forage for pollen and nectar. The segment does hold many trees and bushes, but not many fruit-bearing which creates long distances with no forage opportunities. The flat terrain can cater to some solitary bee species, but more nest sites for both ground-nesting and cavity-nesting bees should be provided. The flower patches on the grass lawn hold bulbous and perennial plants flowering in spring, where both Scilla sp. and Crocus sp. is an important source for bees early on the wings, but as they shift into Narcissus sp. and Tulipa sp. and wither away, the patches lose their function as forage sites for solitary bees, and in this way do not provide for the bees throughout the season. The park segment has the potential to become a good habitat for a broad range of solitary bee species.

From translation to creation In the following part six design principles based on the findings in this thesis are presented. The principles were developed through an iterative process of researching and understanding the most important factors to work with, to create a landscape design for solitary bees. The principles are then applied to the site to show an example of how they can develop into a proposed design for supporting bee and biodiversity in Grøndalsparken.

“You learn a lot from doing things you’ve never done before.” - Piet Oudolf, Garden designer (Lecture at AARCH, Aarhus, 25.03.2022)

part three

creation

Design principles

Connecting the solitary bees to landscape design

1. Analyze the site from a solitary bee perspective

sis aly n A

To understand what kind of actions to take in a landscape design catering to solitary bees, it is important to understand the site as seen from the solitary bee’s perspective for sustaining life. The steps of the analysis are explained and exemplified throughout part two: translation in this thesis.

Challenges

2. Consider nest site to forage site ratio Nesting site to forage site ratio should not exceed 150-500 m. As solitary bees have a limited range of movement agency, the actual distance depending on their size, the habitats need to be within a few hundred meters of the forage site when designing for solitary bees. Habitats could both be existing habitats known to hold solitary bees, potential habitats that bees could utilize if a forage site was nearby or constructed artificial habitats for either cavity or ground nesting bees. Nesting and forage site should be thought as a dynamic pair, and no design should hold just one or the other. Distance and availability to the forage site from the habitat is key, and the shorter the distance, the better.

3. Add plants relevant to the site-specific context To create a design with the best conditions to succeed, the plants chosen are alpha omega. Plant communities cannot be generalized and the designer must be attentive to the existing plant community, the soil and other conditions present in the sitespecific context.

ls ntia Pote

4. Supply pollen and nectar throughout a whole season When most of the species peak, the flowers need to peak too. It is important that the bees have access to pollen and nectar throughout their whole season, making it key to time the planting design in a way that it will blossom and release pollen continuously at different times. To support bees that arrive in early spring, flowering trees and bushes are key.

5. Add plants that cater to specific bees To design for solitary bees, it is necessary to choose plant species that sustain their specific needs. To support biodiversity in the best possible way, it is also important to use only native plants if possible. The plant composition of the forage site should be put together according to the needs of the bees in focus of a design. If the design caters to both specialists and generalists, the plant design needs to reflect and be based on the needs of all species in focus.

6. Place plants in clusters for better orientation To give the solitary bees the best possible conditions to forage, the plants should be placed in clusters, mimicking naturally occurring plant clusters, instead of spreading them out in a mixed formation (Strandberg et al., 2021). The bees will be able to orientate well and find their wished source of pollen in a practical agglomeration of flowering plants.

Spring

Autumn

Figure 16. Solitary bee agency range diagram showing distances from 100-500 m. related to the site. 1: 5000

500 m. 400 m. 300 m. 200 m. 100 m.

Solitary landscape design in Grøndalsparken

Based on the analysis of Grøndalsparken, the following part will apply the presented design principles in a design proposal. I have chosen two focus areas for the proposed design. The Southern part I chose to name Lysningen / The Clearing, as the vegetation is woodier and almost has an urban forest character. The sun breaks through in the middle of the site, creating a light open area with room for perennial and annual herbs to grow in sun and half-shade. The North-eastern part I have chosen to name Engen / The Meadow because of its open and flat, sunlit character. In municipal context this area is also called Grøndalsengen The green valley meadow. The two focus areas for the design are presented through plans and principal sections supplemented with the proposed herbaceous and woody plant communities suggested for the site. The two areas lie within a circle of circa 500 meters of each other, to accommodate the recommended maximum agency range of the solitary bees. The planting designs are distributed evenly in the areas, to create forage sites within a short range of existing and possible nest sites.

Siteplan showing the context and focus areas chosen for the design in this thesis. Part three: creation presents a design proposal for Lysningen / The Clearing and a suggestive strategy for design in Engen / The Meadow.

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Siteplan 1: 2500

Lysningen / The Clearing

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An optimized landscape design for solitary bees in Grøndalsparken

Suggested design In this site there is great potential for sustaining a diverse population of solitary bees because of the landscape structure creating a varied base for ground-nesting bees and the nesting sites’ closeness to varied vegetation from both villa gardens, blossoming trees and bushes and various herbs. Through a plant design the foraging biotope can be strengthened and varied further to support a healthy population of bees and attract new species to the site. On site there is already a good pollen supply in early spring due to the amount of Prunus cerasifera and Salix caprea. In the suggested plant design there is a focus on adding more floral resources throughout summer, sustaining a changing population of solitary bees. The plant communities suggested are based on the existing soil and sun conditions as well as they are divided into fractions based on height, so tall herbs do not out-compete small or medium height herbs.

Concept The planting design is made up of different zones to utilize the highest amount of space for more varied vegetation, while still thinking the design into an urban context that leaves room for human activity. The planting design is distributed evenly in the area, to create differing forage sites for near nesting solitary bees, and furthermore placed with care and thought for the spatiality of the site, meaning that the low, dense vegetation is placed in open areas close to paths, medium height vegetation is placed in defined clusters where they can create an interesting spatiality and the tall vegetation is placed at the edges. A small winding path is suggested to run between the low and medium heigh vegetation to encourage wandering and a circular piece of

sitting furniture is placed close to the plant beds to encourage pause, calm and turning the attention to the bees for the human user.

Site-specific planting design Low zones

The low zones are made up of herbs between 10-70 cm. in height The plants should over time spread and become like a carpet. The low zones are established in open areas where there is sun or halfshade. Middle zone

The middle zone is made up of medium height herbs with a varied composition. It functions as an element creating spatiality and division of more open spaces. Edge zones

The edge zones consist of tall and sturdy herbs designed in linear shapes following and utilizing the narrow edges of the site to create more diversity in flowering plants for the solitary bees. The edge zones should dynamically follow the site conditions, both regarding the shape and size of the plant design and growth conditions. The herbaceous communities are described in detail on the following pages 104-109.

10.5 Zoom in siteplan 1: 500 11

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.5 11N

L. var. 2

E. var. 2 Apartment buildings

Swale

Salix trees

Walking path between zones

Circular bench L. var. 1 E. var. 2 Salix tree

The bank South-west facing bank and bushes functioning as existing solitary bee habitat for ground-nesting species

15 14. 5 1 6 15 . 5 1 6 .5

13.5

Villa neighborhood Opportunities for cavity-nesting bees in old brick house structures

E. var. 1. E. var. 1.

Low zone / L. var. 1.

Alchemilla glabra

Geranium sanguineum

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Prunella vulgaris

Trifolium repens

Suggestive example of solitary bee species benefitting from this herbaceous community (based on data from Rasmussen et al., 2016) A. fulva A. quadrimaculata C. daviesanus C. florisomne C. rapunculi H. tumulorum L. albipes M. willughbiella M. leporina

Ranunculus acris

Low zone / L. var. 2.

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Ajuga reptans

Corydalis cava

Lamium pupureum

Pulmonarium obscura

Rinanthus minor

Suggestive example of solitary bee species benefitting from this herbaceous community (based on data from Rasmussen et al., 2016) A. plumipes A. quadrimaculata L. morio M. willughbiella

Middle zone / M

Suggestive example of solitary bee species benefitting from this herbaceous community (based on data from Rasmussen et al., 2016) A. haemorrhoa A. helvola A. manicatum A. quadrimaculata C. daviesanus C. rapunculi C. similis H. tumulorum, L. albipes L. morio M. europaea M. leporina

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Achillea millefolium

Leucanthemum vulgare

Centaurea jacea

Lytrhum salicaria

Centaurea scabiosa

Stachys palustris

Geranium sylvaticum

Tanacetum vulgare

Knautia arvensis

Veronica spicata

Edge zone / E. var. 1

Cichorium intybus

Daucus carota

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Torilis japonica

Echium vulgare

Suggestive example of solitary bee species benefitting from this herbaceous community (based on data from Rasmussen et al., 2016) A. haemorrhoa A. helvola A. manicatum A. plumipes A quadrimaculata C. daviesanus C. rapunculi H. communis L. albipes L. morio

Anthriscus sylvestris

Edge zone / E. var. 2

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Eupatorium cannabium

Lysimachia vulgaris

Verbascum densiflorum

Verbascum thapsus

Suggestive example of solitary bee species benefitting from this herbaceous community (based on data from Rasmussen et al., 2016) A. manicatum M. europaea

Planting plan / Lysningen

Low zone variation 1

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Medium zone

Alchemilla glabra Geranium sanguineum Prunella vulgaris Trifolium repens Ranunculus acris

Achillea millefolium Centaurea jacea Centaurea scabiosa Principal section of the spatial differences between the planting zones 1: 50 Geranium sylvaticum Knautia arvensis Leucanthemum vulgare Lythrum salicaria Stachys palustris Tanacetum vulgare Veronica spicata

The planting plan for Lysningen / The Clearing shows how big clusters of one plant can be distributed. This particular plan has very large clusters of each herb to visually explore what a solitary bee design looks like, but the design could also easily consist of smaller clusters creating a more

dynamic aesthetic experience for the human user. The size of the clusters is not too important, as there is not much data available on what solitary bees prefer. The clusters could also be distributed in a striped manner, creating another visual experience, while still keeping them in groups based on species.

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Planting plan 1: 100 Planting plan showing a suggested layout and distribution of herbaceous community L. var. 1. and M. in The Clearing.

L. var. 1.

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Establishing the design The edge zones could be established with little disturbance to the existing vegetation by simply sowing out the seeds in clustered lines. As the edges of the site does not have a lot of human interference and walking, it is not necessary to mark the design clearly. The seeding should be done in autumn, when other vegetation is no longer dominant and so the seeds can either sprout and overwinter or hibernate during the dormant stage of winter. To establish the middle and low zone, cultivation of the existing soil is needed. Grass turf and top soil should be removed to create room for introducing the plant design and preferable soil can be added. The plants could be planted as cultivated perennials either in spring time or autumn or be sown out in clusters. Planting them as perennial plants would naturally mark the design visually, to keep humans from walking on or interfering with the early-stage planting design. As the design grows and changes, maintenance should be kept low and seasonal.

Maintaining the design The maintenance of the design will differ through the stages of establishment and through the first years of growing. To give the zones the best conditions for thriving and developing in the early stage, seasonal watering and thinning out of grasses is needed. Spontaneous vegetation will occur, and most likely native and site-present plants that support solitary bees will spread and interfere with the design. It is recommended that they are not weeded out, unless they outnumber the intentional vegetation of the design and prevent them from establishing.

Alliaria petiolate, Aegopodium podagraria, Tussilago farfara, Taraxacum sp. and Cirsium sp. are all examples of unintentional plants that could occur, and these are recommended to stay if they appear. The tall plant stems can be utilized for nests by Lasioglossum sp. amongst others. The winding path should be cut and maintained with a scythe in order to be the gentlest to the vegetation. It is recommended that the vegetation is cut down before early spring, and the cut-off can be used for assisted spreading of the seed bank in nearby areas. Cutting down the vegetation should preferably be done by scythe to make room for varying heights and protect insects nesting in plant stems and shrubs.

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The differing types vegetation creates a dynamic and varied forage site for the solitary bees, as well as a varied recreational landscape for the human users.

180 cm.

150 cm.

70 cm. Low zone

Narrow path

Middle zone

Edge zone

Activating the swale

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Principal section of swale with added vegetation Mentha arvensis 1: 50

The rainwater swale on site currently holds Lamium album, Aegopodium podagraria and Taraxacum sp. It is suggested to introduce Mentha arvensis as a way of activating the ditch later in the season, providing for bees such as A. quadrimaculata.

Mentha arvensis

A. quadrimaculata

Thicket

Path

Swale

Low zone

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Mentha arvensis

Engen / The Meadow

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An optimized landscape design for solitary bees in Grøndalsparken

Suggested design In this north-eastern area of the site, it is evident that more flowering herbs should be introduced, as well as bushes and trees that can provide pollen and nectar for solitary bees during springtime. As the area is used as a recreational spot for sports and playing, the big grass lawn has a valid function in a human and urban perspective. The focus of the proposed strategy for this area is therefore to introduce more flowering tree and bush species, to activate the edges of the site as a better forage site for solitary bees by planting tall herbs and to introduce landscape structures that can serve as nesting sites. It is also proposed to include elements such as bigger stones, that can act as guiding elements in the landscape, making it easier for the bees to navigate the vast grass lawn. This is thought into a landscape design that still leaves room for the human activities such as sports, playing and sitting. The open lawn can be utilized better, if the thicket and edges are thought into a vegetative strategy supporting solitary bees, and if flower patches are added or the existing flower patches are optimized. As the landscape structure and use is of a very different character in this site than in the southern part, the proposed design is also different in its character.

Concept The plant communities from The Clearing are repeated in this area, but single standing tress and groupings are also placed as well as different species of bushes are added to the thicket to create plentiful resources for solitary bees. This strategy can also support better connections to the forage and nesting sites that are present

West of the train tracks in the Copenhagen part of Grøndalsparken.

Woody plant community The woody plant community is made up of blossoming trees and bushes that can supplement the existing trees and bushes in the site to make it a better forage site for solitary bees throughout the spring season. The trees and bushes also add a new spatiality and function for humans in the site. The white and rose floral flower blooms add aesthetic value and visual variety in the park. The woody plant community is described in detail on pages 120-121. The herbaceous communities (Low zone, Middle zone and Edge zone) are described in detail on pages 104-109.

Artificial nesting sites In The Meadow, more opportunities for nesting are needed. To create nest sites for the ground-nesting species, bee-banks are suggested as an experiment to see if the solitary bees of the area can and will utilize these. Nests for cavity-nesting bees, Habeetats’ Ingemann model, are provided and placed in strategic spots on site with shelter from the wind and exposed to sun. Big stones can be placed near nest and forage sites, to create markers the bees can use to orientate. These stones can also be placed in a manner that makes them function as seating or for play and exercise.

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Existing landscape of the lawn, facing South Grøndalsparken, May 2022

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Prunus cerasifera Salix aurita

Nests for cavity-nesters E. var. 1.

Prunus cerasifera Prunus spinosa

Stone Ribes nigrum + Ribes uva-crispa

Bee bank Crataegus monogyna

L. var. 1 Existing flower patch

Villa neighborhood Opportunities for cavity-nesting bees in old brick house structures

Salix caprea

Malus sylvestris

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Zoom in siteplan 1: 500

Tr ai

West Grøndalsparken Plentiful bushes and trees as forage and nest site for solitary bees

Rosa canina

rac ks

Crataegus laevitaga

Bee bank L. var. 2

E. var. 2.

Stones

Nests for cavity-nesters Existing flower patch

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7.5

L. var. 2

Sorbus aucuparia Prunus avium

8 Playground Malus sylvestris 8.5

Ribes nigrum + Ribes uva-crispa

Malus sylvestris Prunus avium Sorbus aucuparia

Woody plant community

Suggestive example of solitary bee species benefitting from this woody plant community (based on data from Rasmussen et al., 2016) A. carantonica A. clarkella A. fulva A. haemorrhoa A. helvola A. plumipes L. albipes L. morio

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Crataegus leavitaga

Prunus cerasifera

Rosa canina

Crataegus monogyna

Prunus spinosa

Salix aurita

Malus sylvestris

Ribes nigrum

Salix caprea

Prunus avium

Ribes uva-crispa

Sorbus aucuparia

Plan and principal section of solitary bee bank 1: 50

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The bank should be constructed in a sun-exposed environment and made in a crecent moon shape to create different angles and a lot of surface area (Buglife, 2020)

Edge zone 180 cm.

80 cm.

Section AA

1 m.

Low zone

Added builders sand with varied grain size

Removed grass turf and top soil with roots

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Establishing the design The low, middle and edge zone plant communities are established in the same manner as suggested for The Clearing. As the area of The Meadow is used more for recreational human purposes, signage during establishment might be needed to communicate the boundaries for the design. Another option could be establishing permanent physical edges to the low and middle zones, using bent steel to create low plantbed edges. This could also prevent the grass from spreading into the plant design. Trees and bushes are established in the existing soil by excavation. The bee banks should be constructed in the time period between November-March, so the first solitary bees on their wings can utilize them for nesting. The banks can be constructed using builders sand or other sandy soil qualities with varying grain size (Buglife, 2020).

Maintaining the design The maintenance of the design will differ through the stages of establishment and through the first years of growing. To give the zones and woody plant community the best conditions for thriving and developing in the early stage, seasonal watering and thinning out of grasses is needed. Spontaneous vegetation will occur, and most likely native and site-present plants that support solitary bees will spread and interfere with the design. It is recommended that they are not weeded out, unless they outnumber the intentional vegetation.

Cutting down the vegetation should preferably be done by scythe to make room for varying heights and protect insects nesting in plant stems and shrubs. Alliaria petiolata, Aegopodium podagraria, Tussilago farfara, Taraxacum sp. and Cirsium sp. are all examples of unintentional plants that could occur, and these are recommended to stay if they appear. The tall plant stems can be utilized for nests by Lasioglossum sp. amongst others. It is recommended that the herbaceous vegetation is cut down before early spring, and the cut-off can be used for assisted spreading of the seed bank in nearby areas. Trees and bushes should not be trimmed just before the blooming season, as that will prevent them from being a source of forage for solitary bees. The bee banks should be kept free of too much vegetation, as most ground-nesting solitary bees prefer sparse vegetation to be able to excavate their nests. The Habeetats nests can be inspected to check and keep an eye on the brood as well as visually inspect and note which species might establish in the nest. The artificial nest sites are a good opportunity for creating a learning environment for kids and adults, to engage users of the park in the new design.

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“Designing with biodiversity in mind is not just a new ‘ecological fashion’ in modern landscape architecture. It is a very important ecological strategy and one of the crucial parts of urban sustainability concept.” - Ignatieva., 2010, p. 140

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part four

reflection

Solitary bees influencing Landscape Design Reflections on how solitary bees can directly influence urban planning and landscape design in practice

The following part will go through a series of reflections on the thesis approach and findings, discuss where the thesis lands and look to which windows it opens for further development in the field of landscape design.

Already designed In the work with Grøndalsparken as a site for the framework, it became clear that the park already has many potentials as an existing design and an already established and relatively diverse biotope. This is an advantage because there are already solitary bees present on site that can be supported. The thesis design proposal therefore became a suggestion of how to optimize an existing design, which is highly relevant for many urban sites where existing green areas could add more value to non-human users in an urban biodiversity context. An advantage with working with a clean slate in another context, for example establishing a landscape design in a newly developed housing area, would be the ability to alter the terrain in a way that from the beginning caters to ground-nesting bees as well as base the plant communities on principles supporting solitary bees from the get-go. A fresh design also brings the opportunity for creating plant communities with more demanding needs in terms of soil conditions, as different soil types can be used. The analysis and proposed landscape design for solitary bees in Grøndalsparken points to multiple potentials in the site. The site-specific design is suggested based on the existing conditions on site, both regarding known solitary bee species and herbaceous and woody plant communities that thrive in the environment of an urban public park. This may lead to an advantage for some herbal species that thrive in soil with high nutrition and high productivity, and it means that herbal species growing in less nutrient rich conditions are left

out of the design proposal. The thesis seeks to accommodate that, by proposing multiple different herbaceous communities with different growth conditions and productivity, based on Ellenberg values, plant height and natural habitat, to still increase the forage opportunities for solitary bees.

22 out of 292 In this thesis I, as a delimitation due to time constraints and resources, only touch upon 22 bee species chosen based on the available data I could find on solitary bees in Copenhagen and Frederiksberg. The chosen species were mostly the ones highest in findings because I wanted to create a realistic design and principles catering to many different species that would with certainty live and thrive in the urban environment, as this was my focus area. This had the effect that the thesis does not focus on endangered or very rare species, which could have been a valid, relevant and interesting approach. The hope is that through designing for these 22 solitary bees, both specialists and generalists, representing different families a design could also with time attract other species within the families, as well as support not only solitary bees but other pollinators such as flies, butterflies and social bee species.

The bee biases Bees with their furry appearance can be considered a charismatic representative for insects, and this was a bias I walked into the project with. During my research, I found that my interest and “tolerance” for interacting with other insects increased, and it is an interesting thought that more knowledge and information from the field of entomofauna maybe can help to raise awareness and ultimately

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tolerance and excitement for insects in our urban environments.

where they can be observed and become visually represented to humans in the urban context.

Throughout the thesis it has become apparent to me, that ground-nesting bees are less present in urban planning and the public eye, and this could be caused by several reasons. The way bees are generally communicated and perceived is often with a definition of bees in hives or colonies, or bees and other insects living in cavities. Previous to writing this thesis, wild bees were to me an undefined and homogenous group of insects, with no real individual characteristics and honey bees or bumble bees were what I immediately thought of when thinking and talking about bees. This exact notion might confuse the conversation about how to create bee-friendly designs, as honey bees and bumble bees have some of the same behaviors and needs as the soitary, but solitary bees are far more diverse and rely greatly on the right conditions and opportunities for forage and nesting. The social bees are more dependent on each other, and therefore have another kind of resilience and less needs to attend to in a design. Ground-nesting bees, making up a big portion of the solitary bees in urban context, might also be harder to communicate simply because of their physical presence underneath the surface making them harder for people and designers to engage with or understand, because things that exist beneath the ground are harder for humans to grasp. Not knowing that their appearance differs greatly from honey bees, most people will not know that they are encountering solitary species when they are spending time in the flowering plant-beds or tree canopies above.

Design as a gateway to mutual understanding and interest

Solitary bee specific landscape design could serve as a platform where attention is brought to the existence and diversity of solitary bees - a platform

How can landscape design tell and communicate a story about what it does, and can it become a common ground for better understanding and caring for nature? “(…) ‘Indirect’ ecological problems, such as the loss of biodiversity and the deterioration of ecological services, are much more complex, more difficult for most people to understand, and require solutions that involve the simultaneous resolution of many interacting factors.” (Müller et al., 2010, p. 609) Complex problems need multi-faceted solutions, and part of designing in the urban space can also be communicating and telling a story that creates interest in the public, engages people and validates the room biodiversity “takes up”. This is especially the case for the urban areas where humans and their needs are traditionally the primary design parameter considered, and it can seem questionable to incorporate other living organisms needs and behaviors in a design. Landscape design has the potential to become a gateway to better understand complex fields of science such as biodiversity, as well as a way of sparking interest and fascination about plants and pollinators, not only for landscape architects and planners, but also through a communicative strategy including the citizens experiencing and daily interacting with a landscape design. To actively engage people in learning about nature, information and communication evidently needs to

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be thought into the design. This thesis focuses on exploring the premise of designing with the solitary bees as the main client, to see which needs and design parameters unfold when the human users are no longer the only ones in focus. It does so in the context of communicating to designers and planners. An obvious next step and layer to the thesis would be to activate a layer of storytelling, for example in the form of signage, wayfinding, information and learning material and a strategic communication effort from planning instances. Another layer to the design could be activating not only solitary bees’ senses but also human senses through the design. This could be by creating pockets of aromatic herbs, making seating platforms surrounded by tall herbs or placing descriptive signs that tell a story of the observed bee species people can look for in the plant design. A good landscape design can become a facilitator of sensory experiences, facilitating better understanding for and connection with nature.

Interdisciplinary practices and design “(…) It is important to realize that although there are numerous research activities and good practices in relation to urban biodiversity worldwide, there is a tremendous lack of information and action compared with other fields of biodiversity and indeed, other aspects of ecology.” (Müller et al., 2010, p. 609) As stated above in Müller et al.’s text, there has been a gap between the existing knowledge and research on urban biodiversity and the urban planning instances actively implementing it in regular practice. Since the text was written in 2010, I will argue that a lot has happened regarding incentives, policies and in the field of landscape architecture,

where urban biodiversity is now a present discourse incorporated in the practice. But there is a risk that the newest knowledge is not applied directly into design practice and that standard phrases instead become the basis for design. Research activities have a great potential to impact the status quo of urban planning, if the fields become better at communicating, experimenting and cooperating. “The future of biodiverse landscapes is directly dependent on an integrated approach and on cooperation of landscape architects, ecologists, architects and urban planners.” (Ignatieva, p. 139, 2010) Working with biodiversity within landscape design evidently calls for a better interdisciplinary practice, which focuses on building bridges not just between different professionals but also between different fields of science that are intertwined. There is an urgent need for common understanding, collaboration and communication between experts, the field of research, designers and planners to explore better design solutions for a future that can hopefully hold more plant and animal diversity in our urban environments. This thesis does not claim to know and explore all the complex aspects of solitary bees and their route to thrive in the urban environment, but it gives an idea of how to explore and implement new kinds of design parameters in the current landscape design context, based on an interdisciplinary ecological approach.

Rethinking design parameters In direct linkage to interdisciplinary work, comes a re-arrangement of design practices and design parameters. This thesis sought to spring from the perspective of solitary bees as non-human actors, to better understand and work with the

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complex problems related to biodiversity and entomofauna loss as a global issue, and to re-shuffle the normalized human-centric approach to urban planning and landscape design. The result of this exploration was a method that focuses on the needs and behavior of solitary bees, as well as a design proposal and strategy focused on how they can be sustained better in the urban environment. Throughout the work with expanding my own horizon to what can inform design choices, new understandings of non-human interactions also emerged. These interactions between plants, insects, soil, sun, water and wind worked as a base for the design actions I needed to take, making it less relevant, in this project, to look at for example human flow and interactions. This leaves space for curiosity and alternative landscape design inspired and informed by a holistic nature philosophy, not excluding the humans but raising plants and solitary bees to the same level of importance. In the last phase of the project where a design proposal was developed, the human interactions with the landscape did appear and affected the way I distributed and thought out the design, although the solitary bee behavior and needs and the human ones were worked with in tandem to create a design that left room for both.

Time is of the essence During the thesis process, time as a resource has been of the essence, as I acknowledged that designing for solitary bees not only means obtaining knowledge about their biology, ecology and phenology but also obtaining knowledge about the diverse factors needed to design well-functioning plant communities for them. This knowledge is not obtained in a few days, but through an iterative process with the help of others’

expertise and experience as well as cross-references in different lexica, and I would argue that it is a continuous process where evaluation and re-design over time should be part of the maintenance plan. As the thesis had a timeframe of four months in total, this created some barriers and constraints for how much knowledge I was able to obtain and how much field work I could carry out. As an example, during the season this thesis was written (February to late May), it was not possible to get a fulfilling overview of the different floral resources throughout a whole solitary bee season, and this is a bias worth being aware of. This thesis therefore places itself in the explorative phase of a framework for designing for solitary bees and ultimately bee and biodiversity. The framework cannot be considered finished, as the thesis timeline left no room for carrying out a trial design and the thesis was carried out during only a third of the flying and flowering season, leaving no time for surveys and fieldwork representing a full season on site. This does not mean the framework should be considered unfulfilling, but that it is in a beginning phase taking shape and it explores how such a framework could be developed further. The next step would be to do more fieldwork and team up with biologists, designers and planners to fully explore the potential of the interdisciplinary approach. I met shortly with a biology student at KU writing her master thesis about the vegetation in Grøndalsparken, and this was very useful to get new perspective on my own analysis. It would have been relevant to collaborate with her and share more knowledge in an iterative design process, if the thesis was to go on. The analysis method of this thesis possibly presents a challenge for the regular planning practice, as it suggests site-analysis throughout a full season, evidently arguing for a slow and timely process with attention to small details.

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Throughout the work with this thesis, it has become clear that to incorporate a deeper understanding for solitary bees in landscape design, there is a need for attention to the smallest details, as well as a need for time and dedication to the ecology of a landscape design. There is also a need for interdisciplinary work and closer cooperation between biologists, designers and planners. This thesis is a first draft of what a framework for including solitary bees as a landscape design parameter could look like, and a proposal for design principles that could be applied in an urban context in Denmark, with Grøndalsparken as the example case. Design principles are in their nature generic, and to develop principles that can contain and endure diversity in the shape of different contexts, more time and research is needed. The design principles brough forth in this thesis can be used as an exploration of design based not only on human needs, but also on the needs of fauna and flora in the urban setting. Applied in practice, the design principles form a dynamic plant design with a focus on native plant species and aesthetic experiences visually differing from the ones usually experienced in public parks, where mixed flower-meadows often dominate as the “wild” or biodiverse element. The design feeds into the policy of Frederiksberg municipality, in their aim to improve and support biodiversity and quality of animal life, to use more native plants and to add new visual and aesthetic experiences for the citizens.

Conclusion

Using knowledge about solitary bees, their behavior and needs can inform landscape design to become more mindful of interactions and interrelations between plants and pollinators. Design choices based on valuing solitary bees as an active and important partaker in urban ecosystems and urban biodiversity, can aid in making design choices that sustain and increase biodiversity in landscape design. Doing this asks more of the designer in terms of plant and ecology knowledge, making it key that the design process holds space for interdisciplinary work and research. Designing for solitary bees in the urban landscape brings new principles into play. It sheds light on the importance of knowing where the wild bees in cities live, as well as where they can thrive, how big their range of agency is and what they prefer in terms of both forage and nest. There is a need for thinking not just about providing food for solitary bees in urban areas, but also to find and keep their existing nest sites as well as give them new ones and explore how that can possibly aid in increasing their numbers as well as the floral diversity in urban areas. The thesis concludes that solitary bees can be a design parameter shaping a landscape design, and that the future practice of landscape design calls for including and normalizing a holistic approach where fascination and care for nature can inspire and inform the design decisions shaping the urban landscapes. Curiosity and exploration of the equal wonders and global issues to be found in the field of biology, as well as the political momentum to do something about the biodiversity crisis, can become an endless source to new design parameters, principles and inspiration for landscape design.

132

The following detailed descriptions of the different species take their starting point in the phenology and ecology of the female bees, as they are the individuals collecting pollen and choosing nest sites to provide for the coming generation. They have the most particular behavior and needs, and that is why the focus is delimited to describing them. The male bees are equally important to uphold the life cycle, but they do not have as many needs and factors that need to be considered and catered to in a landscape design.

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lexicon

the bees of Solitary Landscape

134

135

Family

Andrenidae

Andrena haemorrhoa

136

(Fabricius, 1781)

A. haemorrhoa is a reddish brown and white bee with a length of 10-12 mm. This bee can be an important source of pollination in fruit orchards. Generalist with preferences: Taraxacum, Ficaria verna, Leucanthemum vulgare, Lamium album, Prunus spinosa, Crataegus, Prunus avium, Salix caprea, Rubus idaeus, Ribes rubrum, Ribes nigrum, Ribes uva-crispa. Habitat and nesting: Common in parks, roadsides and gardens. Nests in open spots with sparse vegetation, where the soil is sandy, but can also nest in harder clayey soil types.

On the wings: April – End of July Findings: Found in Copenhagen and Frederiksberg.

Andrena tibialis

137

A. tibialis is a 12-15 mm. long bee with dark brown, beige, white and orange hairs. It has characteristic orange hairs on the hindleg. Generalist: This bee is polylectic and collects pollen from various flowering plants, with a preference for blossoming trees and bushes. It mainly collects from five plant families: Aceraceae, Asteraceae, Brassicaceae, Rosaceae and Salicaceae. Habitat and nesting: Nests in open, sandy soil with sparse vegetation. Can also nest in harder, clayey soil.

(Kirby, 1802)

On the wings: April – End of June (Seldom, July/Mid August) Findings: Found in Copenhagen.

Andrena fulva

138

(Müller, 1766)

A. fulva is a 12-14 mm. long bee with a characteristic, illuminating red appearance. It has red hairs on the back thorax as well as the abdomen and black hairs on the bottom part and legs. It has the common name Tawny mining bee. Generalist: This bee collects pollen from a broad variety of flowering plants, specifically ten different plant families. Aceraceae, Aquifoliaceae, Berberidaceae, Brassicaceae, Buxaceae, Caprifoliaceae, Fabaceae, Grossulariaceae, Ranunculaceae, Rosaceae and Salicaceae. It is drawn to blossoming bushes. Habitat and nesting: This bee is common in the urban environment in parks and gardens. It nests in open, sun-exposed landscape. Nests can be up to half a meter deep.

On the wings: Mid March – Mid June Findings: Found in Copenhagen and Frederiksberg.

Andrena carantonica

139

A. carantonica is a 12-14 mm. long bee with a black, brown, beige and at early stages orange appearance. It has a two-colored dark and light hindleg. Generalist: The bee is polylectic, collecting pollen from various flowering plants. It has a preference for blossoming trees and bushes, such as Crataegus, Malus, Prunus spinosa, P. avium, Salix caprera, Acer platanoides, Rubus idaeus. Habitat and nesting: The bee is common in the urban landscapes such as parks and gardens. Nests in open landscape, sandy field or lawn with sparse vegetation, but can also nest in harder, clayey walls. A group of A. carantonica females can use the same main entrance to the nest site, but build their own, individual brood cell corridors.

(Peréz, 1902)

On the wings: April – Mid July Findings: Found in Copenhagen and Frederiksberg.

Andrena helvola

140

(Linnaeus, 1758)

A. helvola is a ground-nesting bee of 11-12 mm. It has orange-colored, beige and white hairs.

On the wings: April – End of July

Generalist with preferences: This bee collects pollen from a range of flowering plants but is especially drawn to flowering apple- and pear-trees. Malus, Pyrus communis, Prunus spinosa, Crataegus, Ribes alpinum, Prunus padus, Anemone nemorosa, Rubus fruticosus, Ribes uva-crispa.

Findings: Found in Copenhagen and Frederiksberg.

Habitat and nesting: Open, flat landscape where there is sandy or harder soil and sparse vegetation.

Andrena clarkella

141

(Kirby, 1802)

A. clarkella has a length of 12-13 mm. The bee has a characteristic reddish thorax and a reddish hindleg that contrasts the rest of the body. Willow-specialist: This species is oligolectic on Salicaceae and exclusively collects pollen from willow species. E.g., Salix caprera and Salix cinera. Habitat and nesting: Nests in sandy soil with sparse vegetation. The nests are seldom deeper than 5-10 cm below ground, and preferably built in sloping terrain or hillsides.

On the wings: Mid March – End of May Findings: Missing data.

142

143

Family

Colletidae

Colletes similis

144

(Schenck, 1853)

C. similis is a 8-12 mm. bee with beige, brown and redbrown hairs. It has a dark band creating a stripe pattern on the hind part Specialist: This bee is oligolectic on Asteraceae. It collects pollen from e.g., Cota tinctoria, Tanacetum vulgaris and Pentanema salicinum. Habitat and nesting: Common in the urban environment. Nests in sandy soil with sparse vegetation and in clayey slopes.

On the wings: June – Mid September Findings: No data from used sources, but found near Copenhagen according to users at Naturbasen.dk

Colletes daviesanus

145

C. daviesanus is a 7-10 mm. long bee with yellow-brown and grey-brown hairs. It has a dark band creating a stripe pattern on the hind part. Specialist: This bee is oligolectic on Asteraceae. It collects pollen from e.g., Leucanthemum vulgare, Cota tinctoria, Tanacetum vulgaris Habitat and nesting: Common in the urban environment, gardens, parks etc. Nests in harder soil in sloping terrain, or where there are existing, fitting cavities. Can also nest in porous material in buildings.

(Smith, 1846)

On the wings: Mid June – End of August Findings: Found in Copenhagen.

Hylaeus communis

146

(Nylander, 1852)

H. communis is a very small bee (5-7 mm.) with a mainly black appearance with lemon-colored facial markings.

On the wings: Mid May – End of August (seldom Mid September)

Generalist: Collects pollen from a various range of plants but has preferences for Apiaceae with its flat-topped cluster of flowers – examples are Astrantia major, Aegopodium podagraria, Angelica sylvestris and Daucus carota.

Findings: Found in Copenhagen and Frederiksberg.

Habitat and nesting: Nests in empty insect holes in wood, tree trunks, or in bigger bush branches and perennial stems.

147

148

149

Family

Melittidae

Melitta leporina

150

(Panzer, 1799)

M. leporina is a 10-12 mm. bee with light, yellow-brown to yellow-grey hairs. It has a black band creating a clear stripe pattern on the hind part. Specialist: This bee is oligolectic on Fabaceae with a preference for Medicago sativa. Also collects pollen from different species of Trifolium. Habitat and nesting: Common in agricultural landscapes, but also ruderals and industrial urban areas. Nests in sandy soil in open fields with relatively dense vegetation of grass and herbs.

On the wings: June - Mid September Findings: Missing data from Copenhagen and Frederiksberg, found in other locations in Denmark accordign to users at Naturbasen.dk

Macropis europaea

151

M. europaea is a 8-9 mm. bee with black, grey and white hairs on the body. It has characteristic yellow-white hairs on the hindleg. Specialist: This bee is strictly oligolectic and only collects pollen from Lysimachia vulgaris and L. punctata. It consumes nectar from seasonal flowers such as Cirsium, Lythrum salicaria, Origanum vulgare, Mentha arvensis and Thymus serpyllum. Habitat and nesting: Common in urban environments, because of the occurrence of L. punctata in gardens and residential areas. Nests in south-facing slopes in sandy soil and with sparse vegetation.

(Warncke, 1973)

On the wings: June – Mid September Findings: Found in Frederiksberg, Rolighedsvej 23, by Hjalte Ro-Poulsen

152

153

Family

Halictidae

Lasioglossum albipes

154

(Fabricius, 1781)

L. albipes is a small (7-9 mm) bee with golden hairs and a metallic shine to its body.

On the wings: Mid April – Mid October

Generalist: Sources pollen and nectar from a broad range of flowering plants, with preference for buttercup flowers and Succisa pratensis.

Findings: Found in Copenhagen.

Habitat and nesting: Nests in mineral soil in open field.

Lasioglossum calceatum

155

(Scopoli, 1763)

L. calceatum is a 8-9 mm. bee with golden hairs and a shiny appearance.

On the wings: April – Mid October

Generalist: This bee is polylectic and sources pollen from as many as 16 plant families. Often appears collecting pollen from Taraxacum.

Findings: Found in Copenhagen

Habitat and nesting: Common in urban environments and prefers open landscape as opposed to forest. Nests in the ground in turf soil.

Lasioglossum morio

156

(Fabricius, 1793)

L. morio is a very small (6 mm.), shiny bee with a metallic appearance in greenish color. Primitively social, meaning that they can occur in nest clusters. Generalist: Sources pollen and nectar from a broad range of flowering plants. Habitat and nesting: Nests mostly in flat terrain, fields, lawns etc. Can also nest in wall mortar and at tree roots.

On the wings: Mid March – Mid October Findings: Found in Copenhagen and Frederiksberg.

Halictus tumulorum

157

H. tumulorum is a very small (6-8 mm.) bee with a metal like shine. It’s appearance and color has given it the common name Bronze Furrow Bee. Generalist: Sources pollen and nectar from a broad range of flowering plants. Habitat and nesting: Nests mostly in flat terrain, fields, lawns etc. in mixed, sandy soil.

(Linnaeus, 1758)

On the wings: Mid April – Mid October Findings: Found in Copenhagen and Frederiksberg.

158

159

Family

Megachilidae

Megachile willugbhiella

160

(Kirby, 1802)

M. whillugbhiella is a 12-15 mm. bee with a dark brown body and beige hairs. The abdomen can appear orange.

On the wings: May – End of August (Seldom mid September)

Generalist: This bee is polylectic and collects pollen from five plant families. Asteraceae, Campanulaceae, Crassulaceae, Fabaceae and Onagraceae.

Findings: Found in Copenhagen.

Habitat and nesting: Common in urban environments. Nests in existing cavities, in wood, brick walls or artificial nests. Uses cut out leaves to line its brood cells.

Osmia bicornis

161

O. bicornis is a cavity nesting bee known as the red mason bee. It is 10-12 mm long and has a reddish and black, striped appearance. It is common in gardens and in urban parks. Generalist: This bee is widely polylectic and sources pollen and nectar from a broad range of flowering plants, with a preference for nectar from the flowering plants in early spring and pollen from various flowering fruit trees such as cherry (Prunus avium, Prunus cerasus), Pear (Pyrus communis), Plum (Prunus armeniaca, Prunus domestica), Apple (Malus domestica) and Raspberry (Rubus idaeus). Habitat and nesting: Nests in walls, in cavities and crevice’s they can find in different material. They readily use human-made nests with the right dimensions and materials. Uses mud to make their brood cells.

(Linneaus, 1758)

On the wings: Mid March - Mid July Findings: Found in Copenhagen and Frederiksberg.

Chelostoma rapunculi

162

(Lepeletier, 1841)

C. rapunculi is a 8-10 mm. bee with a black appearance and few light hairs on the body.

On the wings: Mid May – End of August

Specialist: This bee is strictly oligolectic and only sources pollen from Campanula.

Findings: Missing data.

Habitat and nesting: Common in gardens and parks. Nests in dead wood in left insect corridors, old plant stems, fallen logs etc. and in sun-exposed areas.

Chelostoma florisomne

163

(Linnaeus, 1758)

C. florisomne is a 8-11 mm. bee with a black, shiny appearance and white hairs on the body.

On the wings: Mid May – End of August

Specialist: This bee is strictly oligolectic, and only collects pollen from Ranunculus.

Findings: Found in Copenhagen.

Habitat and nesting: Appear in the urban environment in parks and gardens. Nests in dead wood in left insect corridors, old plant stems, fallen logs etc. and in sun-exposed areas. Has limited flying distance, and distance from nest to foraging site should be a maximum of 150 meters.

Anthidium manicatum

164

(Linnaeus, 1758)

A. manicatum is a 10-12 mm bee with a robust body. It has golden hairs on the legs, reddish hairs on the back and yellow and black markings on the upper abdomen. Generalist with preferences: This bee is polylectic, but has preferences for Fabaceae, Lamiaceae and Scrophulariaceae. Habitat and nesting: Common in urban areas, parks and gardens. Uses plant hairs from Stacys byzantine, Pilosella lactucella and the like to line the brood cells. Nests in existing cavities, such as window cracks, cracks between boards, or natural cavities in wood.

On the wings: June – Mid September Findings: Found in Copenhagen.

165

166

167

Family

Apidae

Anthophora plumipes

168

(Pallas, 1772)

A. pmubipes is a 14-16 mm bee with black and brown fur and orange-colored hairs on the hindleg.

On the wings: Mid March – End of May (Seldom June)

Generalist: This bee is widely polylectic and collects pollen from a broad range of flowering plants. Berberidaceae, Boraginaceae, Fabaceae, Iridaceae, Lamiaceae, Liliaceae, Papaveraceae, Primulaceae, Rosaceae and Schrophulariaceae. Some of the flowering plants it prefers in gardens is Lamium, Pulmonaria, Corydalis, Primula veris and early blooming bulbous plants.

Findings: Found in Frederiksberg (26.03.2022, Rolighedsvej 23 and Grøndalsparken 21.04.2022)

Habitat and nesting: Common in gardens and the urban environment. Nests in warm areas with sloping terrain, in vertical slopes of clayey or hard-pressed sandy soil. Can also nest in brick walls, and also readily uses artificial nests, such as loam walls with drilled holes.

Anthophora quadrimaculata

169

(Panzer, 1798)

A. quadrimaculata is a 10-12 mm. bee with extensive fur in brown, yellowy and beige colors. The bee almost resembles a bumblebee because of its round and furry appearance. Generalist with preferences: This bee is polylectic and collects pollen from a broad variety of flowering plants. Boraginaceae, Crassulaceae, Fabaceae, Lamiaceae and Solanaceae. Some of the flowering plants it prefers in gardens is Nepeta × faassenii, N. cataria, Betonica officinalis and Lavendula. Habitat and nesting: Common in gardens and the urban environment. Nests in existing holes in the ground or in cavities in brick walls. Also readily uses artificial nests, such as loam walls with drilled holes.

On the wings: May – End of August Findings: Found in Copenhagen.

References

Aarhus Universitet [1], Institut for Ecoscience. 2022. Den danske Rødliste; Søg en art. [online] Available at: https://ecos.au.dk/forskningraadgivning/ temasider/redlistframe/soeg-en-art [Accessed 21.03.22] Aarhus Universitet [2], Institut for Ecoscience. 2022. Den danske Rødliste; Bier. [online] Available at: https://ecos.au.dk/forskningraadgivning/temasider/ redlistframe/artsgrupperne/oevrige-leddyr/bier [Accessed 21.03.22] Aarhus Universitet [3], NOVANA. 2022. Ellenbergs næringsindikator. [online] Available at: https:// novana.au.dk/naturtyper/kontrolovervaagning/ indikatorer/indikatorvaerdier/naeringsindikator [Accessed 30.04.22] Architects Declare. 2022. Danish Architects Declare Climate and Biodiversity Emergency. [online] Available at: https://dk.architectsdeclare.com/ [Accessed 01.02.22] Bees Wasps and Ants Recording Society (BWARS). 2020. [online] Available at: https://www.bwars.com/ home [Accessed 18.03.22] Benton, T. 2019. Solitary Bees – Naturalists’ Handbooks 33. Exeter: Pelagic Publishing. Buglife. 2020. How to create a Bee Bank. Carson, R. 1962. Silent Spring. London: Hamish Hamilton Convention on Biological Diversity. 1992 (updated 02.08.2007). [online] https://www.cbd. int/convention/articles/?a=cbd-00 [Accessed 05.05.2022]

170

Danforth, B.N., Minckley, R.L. and Neff, J.L. 2019. The Solitary Bees – Biology, Evolution, Conservation. Princeton: Princeton University Press. Danmarks Naturfredningsforening. 2022. Grøndalen, Grøndalsenge og 5. Juni Plads. [online] Available at: https://www.fredninger.dk/fredning/ groendalen-mv/ [Accessed 04.03.22] Dunlap, T. and Cronon, W. 2008. DDT, Silent Spring and the Rise of Environmentalism. University of Washington Press. Fischer et. al. 2016. Disentangling urban habitat and matrix effects on wild bee species. PeerJ. Available at: https://peerj.com/articles/2729/ Frearson, A. 2022. Bee bricks become planning requirement for new buildings in Brighton. Dezeen. [online] Available at: https://www.dezeen. com/2022/01/24/bee-bricks-planning-requirementbrighton/ [Accessed 20.04.22] Frederiksberg Kommune. 2020. Frederiksberg Kommunes strategi for bynatur og biodiversitet. https://www.frederiksberg.dk/sites/default/ files/2021-07/strategi_for_bynatur_og_ biodiversitet_2020.pdf Frederiksberg Kommune. 2022. Biodiversitet og bynatur. [online] Available at: https://www. frederiksberg.dk/borger/klima-miljoe-og-affald/ klima-og-baeredygtighed/biodiversitet-og-bynatur [Accessed 04.03.22] Gabbianelli, A., Rinaldi, B.M., Salizzoni, E. 2021. Enhancing urban nature: On design, biodiversity and the construction of experience in Italy. Landscape Research, 46;5, 728-747, https://doi.org/10.1080/014 26397.2021.1931072

171

Gathmann, A. and Tscharntke, T. 2002. Foraging ranges of solitary bees. Journal of Animal ecology, 71, 757-764 Giversen, I., Jensen, J., Kristiansen, B. and Norman, L. 2012. Danmarks flora efter voksested. Gyldendal Green Cities Europe. 2022. Biodiversitet i byer. https://www.paperturn-view.com/da/green-cities/ biodiversitet-i-byer?pid=MjM238895&v=2.1 Hicks, D.M., Ouvrard, P., Baldock, K.C.R., Baude, M., Goddard, M.A. Kunin, W.E., et al. 2016. Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows. PLOS ONE. DOI:10.1371/journal.pone.0158117 Hill, M. 1999. Ellenberg’s indicator values for British plants. Hofmann, M.M., Fleischmann, A. and Renner, S.S. 2020. Foraging distances in six species of solitary bees with body lengths of 6 to 15 mm, inferred from individual tagging, suggest 150 m-rule-of-thumb for flower strip distances. Journal of Hymenoptera Research 77: 105-117. doi: 10.3897/jhr.77.51182 Hooper, D., Adair, E., Cardinale, B. et al. A global synthesis reveals biodiversity loss as a major driver of ecosystem change. Nature 486, 105–108 (2012). https://doi.org/10.1038/nature11118. Ignatieva, M. 2010. Design and Future of Urban Biodiversity in; Müller, N., Werner, P. and Kelcey, J.G. 2010. Urban Biodiversity and Design. Blackwell Publishing Ltd. DOI:10.1002/9781444318654

IPBES. 2016. Summary for policymakers of the assessment report of the Intergovernmental SciencePolicy Platform on Biodiversity and Ecosystem Services on pollinators, pollination and food production. [S.G. Potts, V. L. Imperatriz-Fonseca, H. T. Ngo, J. C. Biesmeijer, T. D. Breeze, L. V. Dicks, L. A. Garibaldi, R. Hill, J. Settele, A. J. Vanbergen, M. A. Aizen, S. A. Cunningham, C. Eardley, B. M. Freitas, N. Gallai, P. G. Kevan, A. Kovacs-Hostyanszki, P. K. Kwapong, J. Li, X. Li, D. J. Martins, G. Nates-Parra, J. S. Pettis, R. Rader, and B. F. Viana (eds.).] Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, Bonn, Germany. 36 pages. IPBES. 2019. Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. [S. Díaz, J. Settele, E. S. Brondízio, H. T. Ngo, M. Guèze, J. Agard, A. Arneth, P. Balvanera, K. A. Brauman, S. H. M. Butchart, K. M. A. Chan, L. A. Garibaldi, K. Ichii, J. Liu, S. M. Subramanian, G. F. Midgley, P. Miloslavich, Z. Molnár, D. Obura, A. Pfaff, S. Polasky, A. Purvis, J. Razzaque, B. Reyers, R. Roy Chowdhury, Y. J. Shin, I. J. Visseren-Hamakers, K. J. Willis, and C. N. Zayas (eds.).] IPBES secretariat, Bonn, Germany. 56 pages. https://doi. org/10.5281/zenodo.3553579

172

IPCC. 2022. Summary for Policymakers [H.-O. Pörtner, D.C. Roberts, E.S. Poloczanska, K. Mintenbeck, M. Tignor, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem (eds.)]. In: Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press. In Press. Kongerslev, K. 2020. Diversity and composition of pollinators in urban parks and cemeteries. Master thesis, University of Copenhagen. Københavns Kommune. 2022. Københavns nye strategi for biodiversitet. [online] available at: https://www.kk.dk/brug-byen/byens-groenneoaser/biodiversitet/koebenhavns-nye-strategi-forbiodiversitet [Accessed 01.04.22] Mallinger, R. E., Gaines-Day, H. R. and Gratton, C. 2017. Do managed bees have negative effects on wild bees?: A systematic review of the literature. PLoS ONE 12(12): e0189268. https://doi.org/10.1371/ journal.pone.0189268 Marinelli, J. 2020. How Non-Native plants Are Contributing to a Global Insect Decline. Yale School of Environment / Yale Environment 360 [online] Available at: https://e360.yale.edu/features/hownon-native-plants-are-contributing-to-a-globalinsect-decline?fbclid=IwAR0IQcT3kPlcTSDY9uFq COXedXfvCSppWKgMgiE2B_E5ox4qJC0cwStPfx4 [Accesed 07.05.2022]

McCune, F., Normandin, É., Mazerolle, M. J. and Fournier, V. 2020. Response of wild bee communities to beekeping, urbanization and flower availability. Urban Ecosystems 23, 39-54. McIntyre, N.E., Knowles-Yánez, K. and Hope, D. 2008. Urban Ecology as an Interdisciplinary Field: Differences in the use of “Urban” Between the Social and Natural Sciences in; Urban Ecology – An international Perspective on the Interaction Between Humans and Nature. Springer. Ministry of Environment. 2022. United for a wilder Denmark. [online] Available at: https://dkvild.dk/ english/ [Accessed 07.05.2022] Miljøministeriet. 2022. Vestenvinden. [online] https://mst.dk/friluftsliv/undervisning/ undervisningsmaterialer/danmarks-natur/vejrog-himmelfaenomener/vestenvinden/ [Accessed 10.05.2022] Müller, N. and Werner, P. 2010. Urban Biodiversity and the Case for Implementing the Convention on Biological Diversity in Towns and Cities in; Müller, N., Werner, P. and Kelcey, J.G. 2010. Urban Biodiversity and Design. Blackwell Publishing Ltd. DOI:10.1002/9781444318654 Müller, N., Werner, P. and Kelcey, J.G. 2010. Conclusions in; Müller, N., Werner, P. and Kelcey, J.G. 2010. Urban Biodiversity and Design. Blackwell Publishing Ltd. DOI:10.1002/9781444318654 Moeslund, J.E. 2022. Den danske Rødliste – Bier. [online] Available at: https://ecos.au.dk/ forskningraadgivning/temasider/redlistframe/ artsgrupperne/oevrige-leddyr/bier [Accessed 05.05.2022]

173

Mori, A.S. 2020. Advancing nature-based approaches to address the biodiversity and climate emergency. Ecology Letters (2020) 23: 1729–1732. John Wiley & Sons Ltd. doi: 10.1111/ele.13594. Mossberg, B. and Stenberg, L. 2018. Nordens Flora. Gyldendal Nicolaisen, Å. 2011. Biografisk Leksikon. [online] Available at: https://biografiskleksikon.lex.dk/ Valdemar_Fabricius_Hansen [Accessed 04.03.22] Ollerton, J., Winfree, R. and Tarrant, S. 2011. How many flowering plants are pollinated by animals? Oikos 120; 321-326, Nordic Society Oikos. https:// onlinelibrary.wiley.com/doi/epdf/10.1111/j.16000706.2010.18644.x Oudolf, P. and Gerritsen, H. 2019. Planting The Natural Garden. Third printing 2021. Portland: Timber Press Inc. Poinar, G. 2020. Discoscapidae fam. nov. (Hymenoptera: Apoidea), a new family of stem lineage bees with associated beetle triungulins in midCretaceous Burmese amber. Palaeodiversity 13(1) pp. 1-9. Stuttgart State Museum of Natural History. https://doi.org/10.18476/pale.v13.a1. Poinar, G.O. and Danforth, B.N. 2006. A Fossil Bee from Early Cretaceous Burmese Amber. Science, Oct. 27, 2006, New Series, Vol. 314, No. 5799 (Oct. 27, 2006), p. 614. American Association for the Advancement of Science. https://www.jstor.org/ stable/20031628. Ro-Poulsen, H. 2018. År 0 monitorering af bier i Københavns byskov, Amager. Institut for Geovidenskab og Naturforvaltning, Københavns Universitet.

Sánchez-Bayo, F. and Wyckhuys, K.A.G. 2019. Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation 232 (2019) 8-27. Scheuchl, E. and Willner, W. 2016. Taschenlexicon der Wildbienen Mitteleuropa - Alle Arten im Porträt. Wieblesheim: Quelle & Meyer Verlag GmbH & Co. Schwägerl, C. (2018). The Anthropocene: The human era and how it shapes our planet. Synergetic Press. SLA. 2022. Biodiversity and ecosystem services. [online] Available at: https://www.sla.dk/services/ biology/ [Accessed 01.04.22] SLU. 2022. Artdatabanken. [online] Available at: https://artfakta.se/artbestamning [Accessed 03.03.22] Strandberg, B., Bruus, M. & Axelsen, J.A. 2021. Plantekatalog. Planter, der understøtter biodiversitet. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 46 s. Teknisk rapport nr. 193 http://dce2.au.dk/pub/ TR193.pdf Rasmussen, C., Schmidt, H.T., and Madsen, H.B. 2016. Distribution, phenology and host plants of Danish bees (Hymenoptora, Apoidea). Zootaxa 4212 (1). Magnolia Press, Auckland, New Zealand

174

Rockström, J., W. Steffen, K. Noone, Å. Persson, F. S. Chapin, III, E. Lambin, T. M. Lenton, M. Scheffer, C. Folke, H. Schellnhuber, B. Nykvist, C. A. De Wit, T. Hughes, S. van der Leeuw, H. Rodhe, S. Sörlin, P. K. Snyder, R. Costanza, U. Svedin, M. Falkenmark, L. Karlberg, R. W. Corell, V. J. Fabry, J. Hansen, B. Walker, D. Liverman, K. Richardson, P. Crutzen, and J. Foley. 2009. Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society 14(2): 32. [online] URL: http://www. ecologyandsociety.org/vol14/iss2/art32/ Van der Kooi, C.J. and Ollerton, J. 2020. The origin of flowering plants and pollinators. Science vol. 368 pp. 1306-1308. https://www.science.org/doi/10.1126/ science.aay3662# Vollmer, B.H., and Jakobsen, R.D. 2016. How Wild is Vild Campus. Bachelorproject, University of Copenhagen. https://science.ku.dk/vildcampus/ doc/HowwildisVildCampus__Vollmer_and_ Jakobsen__2016_.pdf Zurbuchen, A. Cheesman, S., Klaiber, J., Müller, A., Hein, S. and Dorn, S. 2010. Long foraging distances impose high costs on offspring production in solitary bees. Journal of Animal Ecology, 79, 674-681. doi: 10.1111/j.1365-2656.2010.01675.x