Wildlife Stepping Stones: A Study of Biodiversity on Green Roofs

wildlife stepping stones: a study of biodiversity on green roofs carmen godinez

wildlife stepping stones: a study of biodiversity on green roofs carmen godinez I spring 2015 I senior project presented to the faculty of the landscape architecture department of the university of california, davis in partial fulfillment of the requirements for the degree of bachelors of science in landscape architecture

accepted and approved by: Loren Oki . UCD . senior project chair

Haven Kiers . UCD arboretum . technical advisor

David de la Pena . UCD . senior project advisor

Ellen Zagory . UCD arboretum . committee member

contents i. signature page

California Academy of Sciences

bee green roof

ii. table of content

Heron’s Head EcoCenter

bird green roof

iii. list of illustrations

32 the arboretum teaching nursery

‘the hybrid’

82 conclusion

iv. abstract

site introduction

v. acknowledgments

the problem

synopsis

the solution

references

10 introduction purpose

38 site forces

objectives

flora found in arboretum

significance

fauna found in arboretum

12 green roofs introduction

site analysis

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design

benefits of green roofs

introduction

biodiveristy in green roofs

flower forms

20 precedents

pollinator syndromes

‘The Venny’

designing schemes

One Tree Hill Shelter

master plan

Lewisham Wearside Depot

butterfly green roof

plant directory

list of illustrations 1 4

10 11 12 13 14

20 21 22 24 26 28 30 31 32

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red poppies california academy of sciences field of lavender field of purple flowers hesperaloe parvifolia field of buckwheat eriodictyon californicum malva neglecta eremocarpus setigerus trifolium repens california academy of sciences museo del oro vegetated rooftop hanging gardens of babylon sod roofs green roof in zurich aerial view of basel, switzerland wildflowers and tall grass sorghastrum nutans pink wildflowers ‘the venny’ one tree hill shelter green roof one tree hill shelter side view lewisham wearside depot california academy of sciences plants heron’s head ecocenter wetland on green roof maintenance on green roof cross section of heron’s head view inside teaching nursery lavandula angustifolia and bumble bee

flickr calacademy skyecandles flickr smgrowers flickr flickr flickr flickr flickr calacademy architype ASLA 2010 Awards unmuseum flickr flickr dw.de flickr flickr flickr chambermadeopera small green roofs small green roofs small green roofs calacademy ecocenterhhp ecocenterhp ecocenterhp ecocenterhp carmen godinez carmen godinez

33 fuschia and hummingbird 34 teaching nursery sign 35 37 38 39 41 42

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carmen godinez carmen godinez carmen godinez aloe and hummingbird carmen godinez view inside teaching nursery carmen godinez planting bed by shipping container carmen godinez native flora and fauna diagram flickr wildflowers and grass flickr close up of plant fllickr flowers and sunlight carmen godinez site analysis plan view flickr anna’s hummingbird and sage flickr western blue bird flickr pipevine swallowtail flickr ground squirrel lavandula angustifolia and bumble bee carmen godinez flickr insect on flower carmen godinez lavandula ‘otto quast’ flickr muhlenbergia rigens flickr agastache rupestris flickr eriogonum flavum flickr cerinthe major ‘purpurascens’ flickr agastache rupestris flickr nepeta x faassenii flickr stachys byzantine flickr salvia officinalis flickr lupinus densiflora flickr penstemon heterophyllus flickr teucrium chamaedry’s ‘nanum’ flickr kniphofia uvaria ‘nancy’s red’ flickr eriogonum flavum flickr cerinthe major ‘purpurascens’

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flickr scabiosa atropurpurea flickr eriogonum fascicularis eriogonum nudum ‘ella nelson’s yellow flickr flickr sorghastrum nutans flickr solidago ‘cascade creek’ flickr ammi majus flickr achillea millefolium flickr aclepias tuberosa flickr thymus praecox arcticus flickr sedum ‘autumn joy’ flickr teucrium cossonii ‘majoricum’ flickr sedum spp. flickr echinacea spp. flickr aster ‘purple dome’ flickr gilia tricolor flickr lobularia maritima flickr sidalcea malviflora flickr zephyranthes candida flickr coreopsis grandiflora flickr aster x frikartil flickr cosmos bipinnatus sonata flickr phacelia campanularia flickr mimulus aurantiacus flickr eschscholzia californica flickr erigeron karvinskianus flickr sphaeralcea ambigua flickr zauschneria californica flickr salvia greggii and salvia x jamensis flickr phygelius x rectus flickr nigella damascena flickr gaura lindheimeri flickr hesperaloe parvifolia flickr aloe aristata flickr thymus x citriodorus flickr origanum ‘betty rollins’ flickr dasylirion wheeleri carmen godinez green roof layers carmen godinez master plan

62 acmon blue

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buckeye common checkered skipper common or gray hairstreak monarch swallowtail sandhill skipper butterfly habitat diagram species, bloom, color diagram butterfly green roof axon butterfly green roof planting plan sweat bee carpenter bee bumble bee green sweat bee species, bloom, color diagram bee green roof axon bee green roof planting plan anna’s hummingbird house finch western scrub-jay bushtit western bluebird house sparrow species, bloom, color diagram bird green roof axon bird green roof planting plan species, bloom, color diagram ‘the hybrid’ green roof axon ‘the hybrid’ green roof planting plan butterfly and bee roof renderings bird and hybrid roof renderings teaching nursery perspective green roof construction details wildflowers

flickr flickr flickr flickr flickr flickr flickr carmen godinez carmen godinez carmen godinez carmen godinez flickr flickr flickr flickr carmen godinez carmen godinez carmen godinez flickr flickr flickr flickr flickr flickr carmen godinez carmen godinez carmen godinez carmen godinez carmen godinez carmen godinez carmen godinez carmen godinez carmen godinez carmen godinez flickr

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abstract Green roofs (roofs with a vegetated surface and substrate) provide ecosystem services including improved stormwater management, more efficient regulation of building temperatures, reduced heat-island effects, and among the most important is increased wildlife habitats. This study reviews the biodiversity on green roofs which may provide some connectivity in a fragmented landscape. In this study, factors that could influence biodiversity in general on green roofs will be researched and applied to a design on reclaimed shipping containers in the Arboretum Teaching Nursery in the University of California, Davis. The goal is to design green roofs that have the potential to provide foraging resources for native wildlife.

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acknowledgments I could not have achieved what I have done without the support of many other people, first and foremost my parents, who are always right behind me in everything I do. Gracias a mis padres por todo su apoyo y sacrificio. Haven Kiers, a kindred spirit in her love for green roofs, has been a valued professor and friend who guided me in this project. Loren Oki who offered his feedback and encouraged me to work harder. Ellen Zagory and all of the UC Davis Arboretum staff were very helpful and motivating.

I’m very grateful of my friends and classmates, without whom it would have been impossible to complete this and other projects, in particular to Taylor Baer, Danica Liongson, Flora Barbash, and my sister Belen Godinez.

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introduction The level of urbanization is constantly increasing. Riparian areas, grasslands, and forests are rapidly disappearing and being replaced by the impervious surfaces of streets, driveways, and buildings, which eventually intensify storm water runoff and enhance stream channel and river erosion. Dramatic changes in population densities and the urban environment are contributing to an unprecedented climate change, while, in turn, the damaging impacts on the urban environment are being exacerbated by this climate change. The results of globally increasing temperatures, melting of the polar icecaps, rise in sea levels, are felt most severely in cities and urban areas (Hopkins & C., 2011). A possible solution to this dilemma is to create more natural environments within cities and help mitigate climate change by using the rooftops of buildings. Green roofs can help create a living architecture within heavily populated areas.

Although green roofs are not the only solution to our environmental problems, they are part of a broader green infrastructure approach.

10 introduction

This approach integrates a range of methods and processes that take storm-water management, temperature control, pollution reduction, reclamation of urban wastelands, lifestyle and health, and economic benefits into consideration. By carefully designing green infrastructure, we can create and modify micro climates within cities and eventually make these environments more habitable to humans, fauna, and flora.

During the last two decades, a large amount of research has been published on the reduction of rainwater runoff for different types of roof greening (Mentens, Raes, & Hermy, 2006), green roof vegetation (Philippi, 2005), storm-water management (Vijayaraghavan & Joshi, 2014), improving roof membrane longevity (Kรถhler, 2005), and summer cooling (Castleton, Stovin, Beck, & Davison, 2010). Among the purposed benefits of green roofs, and one of the least studied, is the biodiversity that green roofs could potentially support. Even though there is a significant body of research (including case studies) about green roofs, green roofs are not often implemented in California. This

might be because much of the green roof plant selection depends on lists from German research. Another reason why green roofs are not implemented in California is because our Mediterranean climate requires summer time irrigation. Many studies have been conducted where summer rain is frequent. Furthermore, the Mediterranean climate creates a unique challenge for green roofs. Further research is needed to identify plant species that would be suitable in many other climatic regions. There is a need to identify plants that can provide other ecological services such as removing contaminants from stormwater and providing resources for native insects and other animals. It has been suggested that green roofs can provide habitat and act as stepping-stones for species whose habitats have been lost or disrupted.

influence biodiversity on green roofs. A study and conceptual design of green roof prototypes in the Arboretum Teaching Nursery will be conducted. The aim of this design is to create wildlife-friendly green roofs that can be readily implemented on top of shipping containers.

The purpose of this study is to explore the ecological factors that above Nearly all butterflies local to the Sacramento Valley are weedy or fugitive species.

number of species at your site. Eriodictyon californicum, Malva neglecta, Eremocarpus

Skillful planting will enable you to maximize both the number of individuals and the

setigerus, and Trifolium repens are just some species that can attract native butterflies.

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green roofs

14 green roofs

introduction to green roofs Green roofs have been around for many millennia. The earliest references to green roofs relate to the Hanging Gardens of Babylon and other roof gardens developed around 600 BC in Mesopotamia. These roof gardens provided a green cooling effect in the hot arid climate of the Middle East. In contrast, in cold northern Europe around 800-1000 AD, sod roofs were implemented, where turf, and sometimes seaweed, was used to line the walls and roofs of homes for wind protection, extreme cold, and rain (Hopkins & C., 2011). There are various types of green roofs that are based on the thickness of the substrate. These include extensive, semi-intensive, intensive, and an elevated landscape. An extensive roof has a substrate of 2-6 inches; semi-intensive roof has 6 inches (plus or minus 2 inches); an intensive roof is greater than 6 inches; and an elevated landscape is 24 inches or greater (Ansel, 2012).

The main point is that the deeper the substrate is, the greater rainwater absorption or retention the system has, and the better its storm water management potential.

left (clockwise) Hanging Garden of Babylon. Sod roofs in northern Europe. 90-year-old

meadow with high conservation value. The work in Basel has been the inspiration for

green roof in Zurich, in which native soil was used and which has become and orchid

creation of innovative replacement rooftop habitat in London.

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16 green roofs

benefits of green roofs The increasing density of our cities is resulting in less open or green space, which has a direct impact on the quality of the city’s environment, micro climate, and ecosystems. There are several reasons for building green roofs instead of conventional roofs. Green roofs mimic some of the natural systems that are lost due to development, thereby reducing the negative effects of development. The benefits of green roofs are habitat for wildlife, storm water mitigation, pollution reduction, decreased ambient temperature, an extended roof lifespan, and improved public health and wellbeing (Oberndorfer et al., 2007). These benefits can further be divided into private and public benefits. Private benefits particularly relate to the building owners and occupants, by having an impact on building costs, comfort levels, and energy levels. In contrast, public benefits are those that are shared by the wider communities and governments, such as through mitigation of the urban heat island effect or buffering the water flows into the storm water systems (Hopkins & C., 2011). In addition, rooftops offer empty and unused space that we can utilize to better our cities and reduce their environmental impact. This would ultimately be an investment for the future.

pollutants into water bodies and causing river banks to erode and flood (USGS Administration, 2011). In contrast, the unmodified hydrologic cycle allows water to return to the earth’s surface as precipitation. This water can either be absorbed into the ground, transpired by plants, or it can runoff the surface into other bodies of water. Green roofs can replace some of the components that are lost to impervious surfaces.

The plants on the green roof replace some of the vegetation that was lost due to development and so the transpiration phase of the hydrologic cycle is replaced. The substrate found in green roofs catches the precipitation and slowly releases it into the drainage system or stores the water. The water is available to the plants so that they can transpire and return the water to the atmosphere and the rest is evaporated from the substrate. As a result, the evaporation and transpiration done by plants helps lower the surrounding temperatures by acting as an evaporative cooler. The delayed runoff from the roof also helps ease the load that the storm water infrastructure deals with during peak flows.

In a typical urban area, rain that falls onto built-up or paved surfaces quickly flows into storm sewers and out into the nearest body of water.

The excess of this storm water runoff brings more environmental problems that include damaging the water quality by carrying urban 17

18 green roofs

biodiversity in green roofs Green roofs are often installed just for functional reasons, and when that is the case the plant community and biodiversity factor is often an afterthought. Most designers are familiar with gardening for wildlife on the ground, but many have not considered introducing insects and wildlife into the urban roofs context (Dakin, Benjamin, & Pantiel, 2013).

Urban rooftops can serve as perfect environments for the facilitation of wildlife habitats. Green roofs designed with no human interaction are huge opportunities for thriving wildlife because there is no foot traffic to disturb their nesting sites. By varying substrates and plant communities, which contain nectar and food sources, biodiversity can generally be encouraged (Dakin et al., 2013). Closer examination of urban green roofs reveal an entourage of fauna including the usual suspects like butterflies, ladybugs, ground-nesting birds and spiders and also snails, worms, and many families of insects (Breuning, 2008).

While storm water mitigation is the usual driver for green roof policy in some countries, endangered species can also direct green roof mandates too. For example, there are studies that took place in Switzerland and England that have found red-listed invertebrates, spiders and birds using green roofs for habitats (Brenneisen, 2006), and legal protection of these species in combination with committed spokespeople have resulted in the creation of policies mandating green roofs for biodiversity.

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precedents

22 precedents

‘the venny’ Holland Park, Kensington Road, Melbourne, Victoria, Australia I Owner: The Venny, Kensington Adventure Playground, in association with the City of Melbourne I Designer(s): City of Melbourne, Lambert, Lincolne Scott I Context: Public community building I Main purpose of green roof: Sustainability, human comfort, research trial in the public domain ‘The Venny’, is a communal backyard and play space for children.

This new facility provides a safe and purpose-built space to meet the special needs of users. It displays a passive solar design and features refurbished shipping containers painted in base colors. An extensive green roof, water cycling and other environmentally friendly elements are in keeping with the educational function of the building. Plants were chosen for their hardiness and disease resistance, and to provide good ground coverage to reduce weed invasion.

Criticism: The planting scheme for ‘The Venny’ includes five different species of Sedum and Oscularia. In my opinion they missed the opportunity to introduce flowering perennials that have the capability of attracting beneficial insects and wildlife. Plants were only chosen based on their resistance to disease and to reduce weed invasion. Native plants could have been selected that still serve these simple tasks but also invite local fauna into the green roof.

left These green roofs showcase passive solar design and features refurbished shipping containers.

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24 precedents

one tree hill shelter Langdon Hills County Park, Thurrock, Essex, United Kingdom I Owner: Thurrock Council I Designer(s): John Little I Context: Public community building I Main purpose of green roof: Biodiversity, aesthetic John Little wanted to design a practical space for the public to shelter from the sun and rain, but just as importantly, they wanted it to be a wildlife habitat and as sustainable as possible in its construction.

The building has two separate roofs. One slopes in one direction (monopitch) and uses reclaimed soil and green waste compost, and the other is flat and filled with crushed brick and concrete. Both of the roofs are planted with drought tolerant plants and with bare space to encourage the soil and concrete to heat up, which is important for invertebrates.

The walls of this building are thin panels filled with log sections from the park, crushed concrete, cans and bottles. Gaps are left between the materials to provide space for birds to nest in the wall cavity. There are also bamboo canes mixed in with the log wall for solitary bees and lacewings (Dunnett et al., 2011).

Criticism: The roof with the rich soil and compost was quickly dominated by weeds. The crushed brick and rubble roof supports diverse fauna, but this roof is suffering from poor drainage which is associated with the high brick content of the roof substrate. At the moment, water from the roof is discharged onto a set of galvanized chains clumped under the outlet.

Goals for the future include releasing the runoff into a small pond or to direct it back onto the walls of the building. Other goals include adding habitats within the building such as bumble bee and bug boxes. top left The roof soon after planting.

bottom left Once established, the two roofs developed different vegetation depending on the substrate.

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26 precedents

lewisham wearside depot Lewisham, London, United Kingdom I Owner: London Borough of Lewisham I Designer(s): Grass Roof Company and Dusty Gedge I Context: Council depot I Main purpose of green roof: Biodiversity, water retention, water quality

There is a tree next to the green roofs so no irrigation system was installed and a plan was created to irrigate the roof using a standard hose if necessary. A London living roofs mix consisting of native herbs and annuals was used.

These green roofs were retrofitted on a small building housing a generator and two metal modular buildings situated alongside the Ravensbourne River. As the borough’s biodiversity action plan – a strategy prepared by the local council to promote target species and habitats within the area – promotes the use of green roofs for biodiversity, the roofs were designed to encourage wildlife (Dunnett et al., 2011).

Criticism: The roofs were watered regularly during the dry periods in May and June, but this has been minimal. One of the minor issues was the presence of weeds, which must have come with the growing medium. Quick weeding resolved this issue but as other vegetation establishes, this type of unwanted vegetation will be kept to a minimum as competition increases.

A further objective was to use these green roofs as an example of good practice to stimulate other managers and departments to consider retrofitting small-scale green roofs on other buildings in the borough’s ownership. Along with a series of small ecological improvements to the river and a small wildlife garden within the depot, the roofs would add an additional feature for wildlife within an area that is essentially all asphalt.

The roof has a gentle slope, and at one end the slope ends in a small area that held rainwater and moss has now established in that portion.

The building has a simple parapet cap with a zinc protection trim. Using a simple geotextile over the membrane, two substrates were used to create a mounded terrain across the roof. The first substrate consists of crushed ceramics (old baths, basins, and toilets) mixed with a small amount of organic green waste compost. The second substrate is a brick-based growing medium with a slightly higher organic content. The depth of the substrate is (1.2-8.0 in). The lower areas were formed to act as a sort of riverbed meandering across the roof to the outlet. left Vegetation establishment was very successful. The roofs are highly visible, promoting a lot of interest and comment.

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28 precedents

california academy of sciences San Francisco, California, United States I Designer(s): SWA Group, Renzo Piano Building Workshop, Stantec Architecture I Context: Museum I Main purpose of green roof: Biodiversity, water quality, energy efficiency This museum located in San Francisco’s Golden Gate Park is praised as the “world’s greenest museum” for its ambitious sustainable design.

The academy’s LEED-platinum building replaces outdated, earthquake damaged buildings that served as the academy’s home since 1916.

away on San Bruno Mountain. It is very difficult for this butterfly species to even find this green roof as their typical range of travel is less than a mile. As a result, no checkspot butterflies visit this roof, but other species for which the new habitat was not so much of a leap are present. It is also known that some of the plants chosen became very invasive and started taking over the whole green roof.

The green roof has proven to be a highlight attraction that introduces visitors to a living experiment in native plant restoration within a major city like San Francisco. More than 1.7 million California native plants, including 25 species fill the academy’s roof. All of the plants were selected for their adaptation to the local climate and ability to attract butterflies in the region as well as birds, and insects, some of which are endangered (“California Academy of Sciences”, 2014) .

The native plants and soil composition of the roof absorb and filter rain water, helping to reduce runoff by more than 90 percent. Less runoff contributes to smaller drains installed, saving the project cost and materials. Some other features include a six-inch layer of soil and plants which insulate the building. Skylights add to the energy efficiency of the building, allowing natural light to filter to rooms below. Visitors can also see how the roof produces its own solar energy through thousands of photovoltaic cells that are mounted around the perimeter of the roof.

Criticism: A primary goal of the green roof was to draw in the endangered Bay checkerspot butterfly which is native to Golden Gate Park.

However, the closest linking habitat for the butterfly is several miles left The California Academy of Sciences is a perfect opportunity to support, advocate,

Francisco and offers many opportunities to learn from and to research on its living roof.

and engage the public in local native plants because it is a popular destination in San

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30 precedents

heron’s head ecocenter Center for EcoLiteracy and Justice (LEJ) I San Francisco, California, United States I Owner: Port of San Francisco I Designer(s): Evocatalyst, Habitat Gardens I Context: Educational community center I Main purpose of green roof: Biodiversity, education, wastewater treatment This living (green) roof was designed to fit in with the surrounding environment at Bay View Hunter’s Point. The conditions are fairly harsh with the high winds and sun exposure that dries out the growing media quickly. The vegetation consists of 39 plant species that are native to the San Francisco Bay Area region. The goal of this living roof was to attract birds, bees, and butterflies. Integrated water management principles were also implemented. The plants are all drought tolerant and the irrigation system (aided by two 5,000-gallon galvanized tanks) was designed as a closed-loop system in order to save water due to waste and runoff.

Recycled and reclaimed materials were used wherever possible. Gravel was purchased from a local quarry just off the property, and rocks and driftwood were collected from Heron’s Head Park. The roof is used as an education tool for the youth showcasing that plants that grow on the property can also grow on the roof.

Criticism: The living roof restores habitat for wildlife and contains two pools. My only criticism is that the water from these pools can quickly evaporate during the dry seasons.

left One of the project goals was to provide an attractive habitat for native birds, coastal annuals, and perennials.

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the site

the arboretum teaching nursery The Arboretum in the University of California, Davis, is a botanical garden, museum, nature trail, and outdoor laboratory and classroom.

Located along the banks of the north fork of Putah Creek, the Arboretum just celebrated the 60th year of providing a unique venue for research, teaching and outreach to the community. The Arboretum staff are consulted by nurseries, landscape planners and other professionals regularly. The staff also conducts in-service training for landscape staff and municipal and county employees. By utilizing educational outreach programs, Arboretum staff and volunteers offer environmental education for elementary school children, workshops and classes, guided tours, field trips and publications. Its gardens, natural setting, and activities, roughly attract 250,000 visitors a year (Anderson, 2010).

The idea for creating an Arboretum first surfaced in the 1920s in discussions that included well-known figures. In 1959, the Arboretum Committee reaffirmed the Arboretum’s goals: to preserve the one unique topographical feature of the campus—Putah Creek channel— 34 arboretum teaching nursery

and its natural vegetation, to research Mediterranean-type plants for use in the Central Valley, to provide specimens not usually available for teaching and research, and to provide a passive recreation area (Anderson, 2010). Since its establishment, the plant collections in the Arboretum have expanded. The Arboretum now includes 17 gardens and collections and represents a living museum (“UC Davis Arboretum,” 2015).

Due to ongoing habitat loss in the Sacramento Valley, urban “wild” spaces, such as the University of California Davis Arboretum, will become increasingly important as refuges for local wildlife in years to come (Novotny, 2003; Spinks et al., 2003). Arboretum management has mainly focused on the health and wellbeing of its valuable plant collection. However, in 2002, the Arboretum underwent a period of extensive self-examination and goal development in the preparation of the UC Davis Arboretum Ten-Year Plan 2002-2012 (Castaneda & Truan, 2006). During the process of this examination and goal development,

left Arboretum Nursery and the Arboretum All-stars at close proximity. Anna’s

above Inside the Arboretum Teaching Nursery where the shipping containers are located.

hummingbird found feeding on an aloe.

A shipping container located by a planting bed designed specifically for wildlife.

Arboretum staff determined that wildlife populations were highly valued by visitors.

The goal for this site, is to study the benefits of introducing green roofs on existing shipping containers located in the Arboretum Teaching Nursery and researching the biodiversity benefits that these green roofs would provide to local flora and fauna. The shipping containers on this site are currently being used for storage of nursery materials. The goal is to have these recycled shipping containers serve multiple purposes.

Not only can they serve as a place to store the tools used in the nursery, they can also provide habitat and foraging resources for wildlife if green roofs are introduced. These green roofs can serve as prototypes that can be easily implemented and serve as stepping stones for the wildlife populations that are highly valued by visitors. The Teaching Nursery is located in the Mediterranean section of the Arboretum and is surrounded on the west, north, and south side by butterfly gardens that contain plants that are part of the Arboretum all-stars group. However,

the east side of the teaching nursery is barren and a new design is on the way which will include an amphitheater, a meadow, a stormwater detention demonstration area, an events lawn, and a bird and bee habitat garden. Green roofs on top of the existing shipping containers would serve as stepping stones for these species as well as have the potential to attract more visitors and educate the public about the various benefits of green roofs. These new green roofs can also serve as prototypes of biodiversity; examples which can later be implemented throughout all of campus.

In addition to the Arboretum Ten-Year Plan 2002-2012 which contains information on improvements to the Arboretum, section 2 of the Wildlife Management Plan (Castaneda & Truan, 2006) presents a summary of the species known to occur in the Arboretum, as well as additional species that might occur if habitat were suitable for them, given their current range and habitat requirements. There are 169 recorded species that include state species of special concern and state 35

threatened species (Castaneda & Truan, 2006). By creating green roofs that are designed for specific species, improvement of habitats can be achieved.

The Problem Along with providing important plant collections, the UC Davis Arboretum also provides valuable habitat for wildlife. Potential for wildlife habitat enhancement is high, and measures to increase this enhancement are needed.

A high level of anthropogenic disturbance, coupled with a degraded waterway and a lack of complex understory habitat are some of the greatest obstacles for biodiversity in the Arboretum. The Arboretum is also home to large numbers of nonnative or invasive species which thrive in altered conditions and compete with native wildlife (Castaneda and Truan).

The changing nature of the Arboretum is comprehensible, given the high levels of anthropogenic disturbance, the agriculture and urban nature of the landscape, and the operational constraints of a world-class botanical garden associated with a major University (Castaneda and Truan). However, enhancement of the wildlife habitat in the Arboretum is possible and an integrated, holistic perspective to ecosystem management will improve the function and structure of the Arboretum ecosystem and its value to wildlife and the community.

The Solution The goal or vision of this project is Improve habitat for native species by utilizing the existing shipping containers so that they can act as stepping stones, connecting gardens. Where shipping containers are is “leftover� unattractive space where all materials are stored. This area could be designed to be more aesthetically pleasing for visitors and attract wildlife at the same time.

As mentioned earlier, green roofs are not often implemented in California, due to the lack of research and reliance on German research.

The creation of these small scale green roofs would be very beneficial 36 arboretum teaching nursery

since plant and building materials will be tested. In short, these green roofs could be used as experiments to see what works and what does not.

Polites sabuleti sabuleti

Battus philenor

Danaus plexippus

Pyrgus communis

Junonia coenia

Plebejus acmon

Strymon melinus

Western scrub-jay

Anna’s hummingbird

House sparrow

House finch

Western bluebird

Bushtit

Green sweat bee

Bumblee bee

Carpenter bee

Sweat bee

Achillea millefolium Common yarrow Epilobium canum California fuschia Erigeron karvinskianus Santa Barabara daisy Nepeta x faassenii Hybrid catmint Penstemon heterophyllus Foothill penstemon

California native plants

left There is great potential in native plants since it increases biodiversity in beneficial ways. The fauna shown are the focal species.

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site forces

site analysis The Arboretum Teaching Nursery is a horticulture hub where teams of staff, students, and volunteers grow plants for the Arboretum collections and for the plant sales which happen once in the fall and three times in the spring.

With the climate, geology, soil, and hydrology considerations factored in, examination of how these items affect the vegetation layer, and ultimately influence which flora and fauna existed historically, exist now, and are possible in the future was researched. The site analysis of the Arboretum Teaching Nursery includes types of vegetation found, signs of biodiversity around and in the nursery, infrastructure on the site, pedestrian circulation, and access points.

Findings: Burrowing holes - signs of wildlife. Burrowing holes provide habitat for organisms. They can also serve as shelter for amphibians, reptiles, small mammals and birds.

Nonvegetated areas - and areas with bare soil are good for nesting.

Majority of bees nest here.

East area - by the gazebo is the most populated. Other than that, there is minimal car and bicycle traffic.

Passive activities - many people strolling, picnicking, walking their dog, jogging, and napping close to the Arboretum.

Mediterranean Collection - Teaching Nursery is located in the Mediterranean section of the Arboretum.

Arboretum All-stars - surround the Teaching Nursery. These all-stars attract a lot of bees, butterflies, hummingbirds, and beneficial insects.

Shipping containers - are used to store all the supplies used by the 40 site forces

volunteers of the nursery. Shipping containers are visible to the public during the monthly plant sales.

Ceramic art pieces - all located in the several planting beds in the nursery. These insect ceramic pieces were made by UC Davis students enrolled in the entomology 1 class which is part of the Art/Science Fusion program . This is a process of engaging a local community to work creatively and develop a permanent piece of public art.

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MONDAVI CENTER FOR THE PERFORMING ARTS

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2

OLD

VET MED CENTER

DAV

GARROD DRIVE

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UC DAVIS / MONDAVI CENTER EXIT

ARBORETUM TEACHING NURSERY

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3

RE BO C G 04AT 6

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ANALYSIS RESULTS 8 4 ARBORETUM RESTROOM

1

Burrowing holes

2

Birds lingering by construction equipment and cut grass clippings

3

Minimal car/ bike traffic

4

Passive activities

5

Mediterranean Collection

6

Arboretum All-stars (see plant list)

7

Bare ground and informal paths

8

Lots of birds by large oak trees

9

Shipping containers used to store supplies

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Teaching Nursery used for growing plants for plant sales and special projects

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Soil storage

12

Gravel

13

Work station

14

GEM parking

15

Meeting area

16

Ceramic art piece

G132

80’

GAZEBO G034

6

x

16

x

14 x

x

11

9

TREE COVER LAWN GARDEN HORSE PENS

x

13

x

UNVEGETATED AREA VEGETATED AREA

10

x

x

WATER

x

x

15 x

SHIPPING CONTAINERS

x

KIOSK CANOPY PEDESTRIAN CIRCULATION

20’

ACCESS POINTS

41

fauna found Table 1 presents a summary of species known to occur in the Arboretum, as well as additional species that might occur, given their current range and habitat requirements. There is no doubt that there are many more invertebrates that occur in the Arboretum than are listed; comprehensive surveys for invertebrates have not been undertaken. The full listed of wildlife present was shortened to species that would be suitable or would like the micro and macro habitats created by green roofs. A full list of the species known to occur in the Arboretum can be found in the Arboretum Wildlife Management & Enhancement Plan (Castaneda & Truan, 2006).

42 site forces

Avian Ants Mallard Argentine Ant Great Egret Velvety Tree Ant Black-crowned Night-Heron Fish Swainson's Hawk Common Carp Mourning Dove Western Mosquitofish Anna's Hummingbird Sacramento Blackfish Nuttail's Woodpecker AMPHIBIANS AND REPTILES Black Phoebe Western Fence Lizard House Finch Pacific Gopher Snake Orange-crowned Warbler Mammals Western Scrub-jay Ornate Shrew Yellow-billed Magpie Broad-footed Mole American Crow Eastern Gray Squirrel Tree Swallow Western Harvest Mouse Bushtit Deer Mouse Western Bluebird Bats Northern Mockingbird Hoary Bat European Starling Pallid Bat Table 1. Wildlife in the Arboretum

Black-tailed Jackrabbit Desert Cottontail Mesocarnivores Domestic Cats Domestic Dogs Native Coyote

flora found The UC Davis Arboretum contains important plant collections and is an aesthetic resource of great value to the Davis community. Tables 2 and 3 present a summary of some of the plant species located in the site.

The list was shortened to plant species that are found in the surrounding gardens in the Mediterranean section of the Arboretum. Table 3 presents the Arboretum all-stars that are found by the Arboretum Teaching Nursery. It is important to know that these plants thrive in California’s Mediterranean climate and have the qualities that can make them great choices for sustainable gardens.

Abies numidica Arbutus 'Marina' Argyranthemum foeniculaceum Callistemon comboyensis Clematis flammula Cupressus sp.

Euphorbia myrsinites Fraxinus xanthoxyloides Genista lydia Iris sp.

Lavandula angustifolia Lavandula dentata Lavandula stoechas 'Otto Quast' Myoporum parvifolium Myrtus communis Olea europaea Osteospermum comboyensis Phillyrea latifolia

Abies Numidica Arbutus 'Marina' Argyranthemum Foeniculaceum Callistemon Comboyensis Clematis Flammula Cupressus Sp. Euphorbia Myrsinites Fraxinus Xanthoxyloides Genista Lydia Salvia officinalis 'Compacta' Sambucus mexicana Santolina chamaecyparissus Santolina pinnata Stipa gigantea Tanacetum fruticans Teucrium fruticans Thymus capitatus Vitex agnuscastus

Achillea millefolium Aloe sp.

Aquilegia Eximia Bouteloua gracilis Callistemon 'Violaceus' Ceanothus 'Concha' Ceanothus maritimus 'Valley Violet' Cercis occidentalis Dichondra arundinacea Echeveria 'Imbricata' Epilobium canum Erigeron karvinskianus Eschscholzia californica Heuchera 'Lillian's Pink' Kniphofia uvaria Lavandula stoechas 'Otto Quast' Lavandula x ginginsii 'Goodwin Creek Grey' Lupinus bicolor

Muhlenbergia rigens Penstemon heterophyllus 'Margarita B.O.P' Rosa sp.

Salvia apiana Salvia clevelandii 'Winnifred Gilman' Salvia greggii Salvia spathacea Sedum palmeri Teucrium fruticans

Table 3. Arboretum All-stars

Table 2. Plants in the Mediterranean section.

left Some of the wildlife that can be found in the Arboretum. right Some of the plants observed int the Arboretum Teaching Nursery.

43

design

introduction Green roof planting designers must consider multiple criteria when planning a design, including design intent; the client’s needs and expected outcomes; budget and maintenance parameters; life expectancy of the green roof; access and safety issues; location; micro an macro environments; humidity or dryness; exposure; maximum and minimum temperatures; medium weight, depth and composition; and irrigation. There must be a careful plant selection to make sure the green roof succeeds. Green roof plants must be tougher and less nutrientreliant than plants found in most gardens.

Multiple planting plans were created based on fauna requirements.

Plants whose fruits, nectar or seeds attract birds, pollinators, or beneficial insects were chosen because they provide habitat for wildlife.

In addition to visual beauty, the new biodiverse green roofs will have a new appreciation for landscape processes and function. The plant selection and landscape structure will ultimately influence the animal species that plants support.

46 design

The plant selection for the design of green roofs is very important. Forms and structures of the plants and flowers also add to the aesthetic appeal of a green roof. The form and structure of plants is more intrinsic to them than color. Flower color is with us for a relatively short season, compared with the shape of the plant. To evoke nature and provide a long-lasting season of interest, gardens should focus on the plant form since the plant color is only an exciting extra.

A perennial has a form that is intrinsic and unique to itself. One can quickly learn that there are many more stages in the life of a perennial that are deserving of study and appreciation than simply the flowersbuds, unfurling leaves, seedheads, autumn foliage, winter’s skeletal remains- although the dominant feature of most perennials remains the flowers and how they are arranged in a head- what botanists call the inflorescence. The first part of this examination will look closely at the flowerheads of the plants selected and the characteristic forms that they take. Some of these forms are often apparent even some time before

the flowers actually emerge from their buds and forms that are, in many cases, strong sculptural features in the garden well after the flowers themselves have died and turned to seed.

Flowerheads come in many forms, all of which have been adapted by nature to attract pollinating insects to the flowers, or, in the case of grasses, to distribute the pollen on the wind. It is these forms that give flowers so much of their distinctive character. The flower forms presented in the next pages are classified as different forms that include spires, buttons and globes, plumes, umbels, daisies, screens and curtains, and leaf shape (for a complete plant list please see the plant directory).

47

form

spires Spires help take our vision upwards, they remind us of other realms, they help connect the earth and heaven. Spire-shaped flowers can help add lift to the garden. Flowerheads shaped like spires differ dramatically from other flower forms and they successfully introduce a sense of clarity among other less defined flower shapes or a mass of foliage. Spire forms have a dominant visual appearance but they cannot stand alone, a clump or loose gathering of spires is always more visually appealing as well as satisfactory.

Flower spires consist of a stem packed with flowers (Oudolf, 1999); the more tightly packed the flowers are, the cleaner the shape is. Some spires even have smaller spires that can branch out from the main one, all of them pointing upwards at the same angle, to create a blurred forest of spires.

above Agastache rupestris right (top to bottom) Nepeta x faassenii, Stachys byzantina, Salvia officinalis far right (top to bottom) Lupinus densiflora, Penstemon heterophyllus, Teucrium chamaedry’s ‘Nanumn, Kniphofia uvaria ‘Nancy’s Red’

48 design

form

buttons and globes Buttons and globes are flowers that are tightly packed together in concentrated clusters. They are also defined points (Oudolf, 1999). Buttons and globes are known to be prominent against soft shapes like plumes or against veils of fine stems. They are often points of concentrated color in the summer. In the wintertime, they are often the only clear points in a garden, standing out against the decay of everything else as dark spots. The number of buttons is increased in winter. The effect that the buttons and globes form has is dependent on how they are arranged in a garden. Some of them are set in whorls on upright stems, others on scattered fine stems.

Since the buttons and globes are spaced out in the stem means that it is possible to see through the clusters of buttons. In some sense, transparent, in the same way that groups of narrow stems are transparent.

above Eriogonum flavum right (top to bottom) Cerinthe major ‘Purpurascens’, Scabiosa atropurpurea, Eriogonum fascicularis, Eriogonum nudum ‘Ella Nelson’s Yellow

49

form

plumes

Plumes are a delicate form, intermediate between spires and umbels. They are also composed of multiple tiny individual flowers, but arranged in a looser, fluffier, often more transparent way. Since they act as intermediate between spires and umbels, they can serve as the “connectors” in the upper reaches of the border. Their vague fluffy quality is most effective in mass, evoking in particular the flowering of marsh plants like reeds. Since plumes tend to be unidirectional, they are especially attractive when they are blown by the wind since all the plumes will blow in the same direction. Putting together too many bold or clearly defined shapes in a border can create the impression of fussiness or can sometimes be overstimulating. The presence of plumes or less clearly defined forms can act like the softness of the color pink, as a linking form, making it easy to bring in stronger, more defined forms.

above Sorghastrum nutans, Solidago ‘Cascade Creek’

50 design

form

umbels Umbels consist of a flower cluster in which stalks of nearly equal length spring from a common center and form a flat or curved surface.

They have the familiar upturned bowl shapes of many common wildflowers and ‘weeds’. These flower characteristics are found in wild, unkempt places. Many of them are not regarded as garden flowers. But once we set aside the idea that all flowers must be colorful to be in the garden, we can begin to appreciate the real beauty of these flower forms. Umbels can be thought of as the opposite of the heaven pointing spires. Their gently rounded shapes counterbalance the energy of the sky-seeking spires. They have a soft and gentle look since they are composed of tiny minute individual flowers and often have a soft and gentle look.

Many of the flower clusters form complex patterns, often umbels within umbels. When used in a garden, umbels lend a look to gentle naturalism.

above Ammi majus right (top to bottom) Achillea millefolium, Aclepias tuberosa, Thymus praecox arcticus, Sedum ‘Autumn Joy’, Teucrium cossonii ‘Majoricum’, Sedum spp.

51

form

daisies A daisy is a small grassland plant that has flowers with a disk and multiple rays. Daisies often remind us of the sun, not just because of their shape but also because they are found in sunny places; meadows, fields and prairies. Daisies are also strongly associated with the sun since most of them flower from midsummer onwards. Daisies can be described as concentrated versions umbels, masses of tiny flowers so closely packed together that they are usually taken to be a single flower, but with the outer flowers having ray-like petals, creating the characteristic daisy appearance.

What’s even more striking is that the central and outside petals are often different colors. After flowering the outer petals generally drop off, leaving buttons behind, which are often very persistent.

above (top to bottom) Echinacea spp., Aster ‘Purple Dome’ right (top to bottom) Gilia tricolor, Lobularia maritima, Sidalcea malviflora, Zephyranthes candida, Coreopsis grandiflora, Aster x frikartil

52 design

above Cosmos bipinnatus sonata, Phacelia campanularia, Mimulus aurantiacus, Eschscholzia californica, Erigeron karvinskianus, Sphaeralcea ambigua

53

form

screens & curtains Plants do not always have solid shapes. Some plants form a network of leaves, stems, and flowers, some of which allow you to see right through them. Think about how you can see right through the stems of grass. Transparent plants are mostly air and they create another perspective as you are able to see the plants directly behind them. Transparency or screens and curtains can sometimes be overdone; it can destroy patterns if too many of the same plants are used, drawing attention from the real concept. Screens and curtains should create the impression that they are everywhere, when in fact they are not. These screens and curtains can allow you to see through or past them to get some idea what is hidden behind. If used correctly, they can effective combinations of colors and form as well as romance and mystery.

above Epilobium canum right (top to bottom) Salvia greggii and Salvia x jamensis, Phygelius x rectus, Nigella damascena, Gaura lindheimeri

54 design

leaves

shape Shapes help the way we see the world. Leaf shapes have an effect that is often accentuated by distinctive or attractive coloring or texture. Leaf shapes have the strongest effect, especially in the short of middle distance of a garden. Since plants often lose their flowers, it is wise to pay attention to the value of foliage in a garden.

Plants with large or bold leaves create a different effect than small leaves or leaves that are divided into many small leaflets.

above Hesperaloe parvifolia right (top to bottom) Aloe aristata, Thymus x citriodorus, Origanum ‘Betty Rollins’, Dasylirion wheeleri

55

plant traits and the pollinators they attract Plants can be grouped together based on the similar characteristics of their flowers. These floral characteristics can be useful to predict the of pollination method or animal that is most effective for that group of plants.

Plants and pollinators have co-evolved physical characterisics. These characteristics allow them to interact more successfully. Both the plant and pollinator benefit from this co-evolution. Plants attract a particular type of pollinator to its flower, this ensures that its pollen will be carried to another flower of the same species, resulting in successful reproduction and genetic diversity. On the other hand, the pollinators benefit from their adaptation to a particular flower type by ensuring that it will find and access nectar and pollen (Forest, 2013). These relationships are considered mutualistic.

Animals, wind, and water can all be carries of pollen. The flower type, color, odor, nectar, shape, and structure vary by the pollinator that visits them. These characteristics are considered pollination syndromes and can be used to predict the type of pollinator flowers can potentially attract.

56 design

Pollinator Syndrome Traits Table

plant traits

bats

bees

beetles

birds

color

Dull white, green or purple

Bright white, yellow, blue, or UV

Dull white or green

Scarlet, Bright, orange, red or including red white and purple

nectar guides

Absent

Present

Absent

Absent

Present

odor

Strong musty; emitted at night Abundant; somewhat hidden Ample

Fresh, mild, pleasant

None to strongly fruity or fetid Sometimes present; not hidden Ample

None

Faint but fresh Putrid

Large bowllike, Magnolia

nectar

pollen

flower shape

Regular; bowl shaped – closed during day

Usually present Limited; often sticky and scented Shallow; have landing platform; tubular

butterflies

flies

moths

wind

Pale and dull to dark brown or purple; flecked with translucent patches Absent

Pale and dull red, purple, pink or white

Dull green, brown, or colorless; petals absent or reduced

Absent

Absent

Ample; deeply Ample; deeply Usually hidden hidden absent

Strong sweet; None emitted at night Ample; deeply None hidden

Modest

Limited

Modest in amount

Limited

Large funnel like; cups, strong perch support

Narrow tube with spur; wide landing pad

Shallow; funnel like or complex and trap-like

Regular; tubular without a lip

Abundant; small, smooth, and not sticky Regular: small and stigmas exerted

above Use the table above to help you identify the potential pollinators you may associate with different flower types.

57

designing schemes Virtually any green roof will attract some wildlife, but to maximize the opportunities for attracting the widest range of invertebrates and plants it is necessary to widen the diversity of ecological conditions on the roof.

These are some of the strategies that will be applied to the design of the shipping container’s green roofs.

Vary the depth of the substrate Varying the depth of the growing medium, preferably between 2-6 in, will allow for a range of microhabitats and growing conditions, providing both dry conditions with sparsely vegetated areas and more lush areas of taller vegetation. The varied substrates will also allow burrowing invertebrates to nest. Mounding and differences in aspect and sun and shade, can provide an even wider array of ecological conditions.

Use different substrates Different substrates, including rubble and stony material, sand, and brick-based or similar media, provide different opportunities for invertebrates. Rubble and stony areas offer shelter and nesting opportunities for certain species. Sandy areas will allow burrowing bees and other invertebrates to have nesting opportunities.

Provide a diversity of plants A diversity of plants will allow a range of invertebrate species to colonize the green roofs. Consideration will be given to plants that provide both nectar and food for butterflies, moths and their caterpillars. Will take plants that flower in early spring and late summer into consideration to ensure that the roofs provide the best possible resource for nectarfeeding fauna. Plant diversity will also increase the sheltering and habitat opportunities for invertebrates.

58 design

Use a diversity of plants and different plant establishment methods From a wildlife perspective, different planting methods have their benefits. For example, plug planting will have almost immediate interest for wildlife. Seeding a range of appropriate species, especially on roofs with a varied substrate depth and type will allow the plants to establish themselves where they want to be.

Provide other structural features Using logs and stones or boulders can add another dimension to small scaled green roofs. These structural features have the potential to offer habitat. Certain plants that struggle on extensive green roofs could be planted on the shady side of such features. Adding invertebrate nesting boxes and sand walls for mining bees can provide more opportunities for nesting.

Relate to the local area The UC Davis Arboretum has its own distinctive native habitats and plant and animal communities, which are related to the Mediterranean climate and the geology of the area. One of the major objectives is to attract and draw wildlife in from the surrounding area. Using native plants or Arboretum all-stars can help achieve this goal. Native vegetation used in the green roofs can also help replace lost habitat and draw wildlife in from the surrounding area.

structural features

vegetation

substrate

Hunter ecomat straw drainage rubber liner geotextile gabion edge roof deck shipping container

8’-0”

20’-0” 8’-0”

above The shipping container green roof build up. Axonometric showing the different layers that make up the green roof.

59

master plan shields oak grove

arboretum teaching nursery vet med arboretum waterway

shipping containers

future meadow and stormwater detention demonstration area

mediterranean section

60 design

stepping stone green roofs

1 butterfly green roof 2 ‘the hybrid’ green roof 3 bee green roof 4 bird green roof

1

2

3

4

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butterfly green roof Butterflies tend to be eye-catching, as are the flowers that attract them.

Some of the most welcoming gardens include ones that have sunny areas that are sheltered from the wind and contain amenities such as leaf litter, rock crevices, brush piles, damp places, and even weeds.

Sun-warmed boulders with shallow, water-filled basins in the top are also desirable. By providing a safe place to eat and nest, gardeners can also support the pollination role that butterflies play in the landscape.

This might mean accepting minimal damage to the plants, known as host plants, that provide food for the larval stage of the butterfly.

Seven butterfly focal species were chosen for purpose of this design and study. Acmon Blue, Buckeye, Common Checkered Skipper, Common or Gray Hairstreak, Monarch, Swallowtail, and Sandhill Skipper are these focal species. They usually look for flowers that provide a good landing platform and they are especially attracted to bright flowers, including red and purple.

Aristolochia californica

Acmon Blue

Buckeye

Common Checkered Skipper Butterflies

Common or Gray Hairstreak

Monarch

Pipevine Swallowtail

Sandhill Skipper

Asclepias fascularis

Chaparral

Asclepias speciosa

Coastal prairie

Aster sp.

Coastal sage scrub

Croton setigerus

Coastal strand

Dichelostemma capitatum

Disturbed

Eriodictyon lobbii

Foothill woodland

Eriogonum fasciculatum

Joshua tree woodland

Lotus scoparius

Meadows

Malva neglecta

Mixed evergreen forest

Malva nicaeensis

Pinyon-juniper woodland

Malva parvifolia

Red fir forest

Medicago sativa

Sagebrush scrub

Phyla nodiflora

Valley grassland

Polygonum aviculare

Wetland-riparian

Scrophularia californica

Yellow pine forest

Sidalcea malviflora Trifolium repens Triteleia laxa

62 design

start bloom time: winter Aquilegia eximia

butterfly vegetation diagram JAN

NG JUN

SUMM

OCT SEP

APR

SPRI

AUTU ER

MAR

UG

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WINT

ER

MN

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DEC OV

EB

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JUL

start bloom time: summer Achillea millefolium Agastache rupestris Ammi majus Asclepias fascicularis Asclepias tuberosa Aster x frikartil Coreopsis grandiflora Cosmos atrosanguineus Echinacea spp.

Erigeron glaucus Goniolimon incanum Eriogonum flavum Gaillardia x grandiflora Malva spp.

Ruta graveolens Scabiosa columbaria Sedum spp.

Sorghastrum nutans

start bloom time: spring Armeria maritima Brachyscome spp.

Dianthus spp.

Centranthus ruber Eriogonum fasciculatum ‘Theodore Payne’ Gaura linheimeri Gilia tricolor Lupinus densiflora Mimulus spp.

Penstemon heterophyllus Salvia officinalis Sidalcea malviflora Silene acaulis Veronica repens year-round Bidens ferulifolia Lobularia maritima

above Butterfly chart showing the genus and species of chosen plants, blooming season,

to increase accountability. bottom left diagram showing focal species, desired plants, and

and color of inflorescence. left Acmon Blue, Buckeye, Common Checkered Skipper,

the preferred habitats.

Common or Gray Hairstreak, Monarch, Swallowtail, Sandhill skipper. The goal of the focal species strategy is to measure the success in achieving butterfly conservation and

63

boulders gabion edge

nectar plants food plants

64 design

Butterfly planting plan

Plant Symbol Scientific Name

Common Name

Sun Exposure Watering Needs Height Width Blooms

Color

Type

AM A Ama AF APD DW E EK EF EC GL GT LM LU PH S SM SN

Common Yarrow Licorice mint Bishop’s lace Narrow leaf milkweed Purple dome Michaelmas Desert spoon Coneflower Santa Barbara Daisy Wild buckwheat California poppy

full sun full sun full sun/part shade full sun full full full full full full full full full full full sun/part shade full full full

white orange white white Purple white yellow white white orange white pink purple white purple deep blue white pink green

perennial perennial annual perennial perennial shrub perennial perennial perennial perennial perennial annual annual perennial perennial perennial/succulent perennial perennial grass

Achillea millefolium Agastache rupestris Ammi majus Asclepias fascicularis Aster 'Purple Dome' Dasylirion wheeleri Echinacea spp.

Erigeron karvinskianus Eriogonum flavum Eschscholzia californica Gaura lindheimeri Gilia tricolor Lobularia maritima Lupinus densiflora Penstemon heterophyllus Sedum (most) Sidalcea malviflora Sorghastrum nutans

Bird's eyes Sweet alyssum Lupine Foothill penstemon Stonecrop Checkerbloom Indiangrass

very low medium low-medium medium low-medium very low-low low-medium low low-medium low-medium medium low-medium medium very low low low-medium medium very low

3’ 2' 1-3’ 2-4’ 2' 3-5' 2-3' 10-20" 10" 1' 3-4' 4-18" 1' 1.5-2' 1-1.5' 2-5" 2' 3-4'

2' 1’ 2’ 2' 4-5' 2-3' 3' 8" 1.5' 3-4' 9" 1' 1.5-2' 2.5' 1-1.5' 2' 1.5'

summer-early fall midsummer-midautumn summer summer late summer-early fall spring-summer summer spring-fall early summer spring-summer late spring-fall late spring-early fall all year spring spring-summer midsummer early spring midsummer

65

bee green roof There are nearly 4000 species of native ground and twig nesting bees in the United States. Some form colonies while other live and work a solitary life. Bees have tongues of different lengths that help determine which flowers they can obtain nectar and pollen from (Forest, 2013).

Encourage all bees into the garden. Bees will go for whatever’s blooming, even if it’s not their favorite. But they are especially attracted to blue, white, and yellow flowers. Hang up a bee box with a grid of small holes in front where solitary bees can nest. Lure bees by planting flowers that produce lots of pollen, and both honeybees and native bee species will zoom in. About 70% of native bees are ground nesters. A small patch of bare earth in a sunny spot-as little as 1 square foot- is all they need.

The remainder are wood nesters; they’ll occupy holes in trees, or move into bee houses or nesting blocks-pieces of untreated wood drilled with a grid of small holes.

Four bee focal species were chosen for purpose of this design and study. The sweat bee (Halictidae), carpenter bee (Xylocopa spp.), bumble bee (Bombus spp.), and the green sweat bee (Agapostemon spp.) are these focal genera. They usually look for flowers that are shallow, tubular, and have a landing platform.

66 design

start bloom time: winter Cephalophyllum ‘Red Spike’

DEC

NG

Y MA JUN

SUMM

OCT SEP

APR

AUTU ER

MAR

SPRI

UG

F

ER

A

bee vegetation diagram

MN

JAN

WINT

EB

V NO

JUL

start bloom time: summer Agastache rupestris Aster x frikartil Sphaeralcea ambigua Coreopsis grandiflora Cosmos bipinnatus Echinacea spp.

Hyssopus officinalis Lavandula angustifolia Origanum ‘Betty Rollins’ Sedum spp.

Thymus x citriodorus

start bloom time: spring Cerinthe major ‘Purpurascens’ Eschoscholzia californica Lavandula ‘Otto Quast’ Mentha spicata Monardella villosa Nepeta x faassenii Penstemon heterophyllus Phacelia campanularia Salvia officinalis Stachys byzantina

year-round Asteriscus maritimus Lobularia maritima

above Bee chart showing the genus and species of chosen plants, blooming season, and color of inflorescence. left Sweat Bee, Carpenter Bee, Bumble Bee, Green Sweat Bee.

67

bare earth

yellow flowers white flowers

blue flowers

bee farms

68 design

Bee planting plan

Plant Symbol Scientific Name AR AF CM CG CB E EN EC LM NP OB PH PC SO SA SAB SB TC TCM TP TCI

Agastache rupestris Aster x frikartil Cerinthe major 'Purpurascens' Coreopsis grandiflora Cosmos bipinnatus Echinacea Eriogonum nudum 'Ella Nelson's Yellow' Eschscholzia californica Lobularia maritima Nepeta x faassenii Origanum 'Betty Rollins' Penstemon heterophyllus Phacelia campanularia Salvia officinalis Sedum spp.

Sphaeralcea ambigua Teucrium chamaedry's 'Nanum' Teucrium cossonii 'Marjoricum' Thymus praecox arcticus Thymus x citriodorus Zephyranthes candida

Common Name

Sun Exposure

Watering Height Width Blooms Needs

Color

Type

Licorice mint

full sun/part shade full full sun/part shade full full full full full full full sun/part shade full full sun/part shade full full full full full sun/part shade full full part shade full sun/part shade

medium medium medium low-medium medium low-medium low low-medium medium low low low low-medium low-medium low low very low-low low low low-medium very low-low

orange blue purple bright yellow white yellow yellow orange white purple light pink deep blue blue blue pink orange pink purple purple pale lilac white

perennial perennial perennial perennial annual perennial perennial perennial annual perennial perennial perennial annual perennial perennial/succulent perennial groundcover groundcover groundcover shrubby perennial perennial

Honeywort

Coneflower Naked buckwheat 'Ella Nelson's Yellow' California poppy Sweet alyssum Hybrid catmint Dwarf oregano Foothill penstemon California desert bluebells Garden sage Sedum 'Autumn Joy' Apricot mallow Dwarf germander Fruity germander Mother of thyme Lemon thyme Argentine rain lily

1.5-2.5' 2' 2' 1-2' 1.5-2' 2-3' 10" 1' 1' 2-3' 3-6" 1-1.5' 6-18" 1-3' 2-5" 3-4' 8" 8" 1-3" 6-12" 1'

1.5' 2'

midsummer-midautumn late summer-early fall spring to fall 3' summer 1.5-2.5' summer-fall 2-3' summer 8" early summer 1.5' spring-summer 1' all year 2-3' late spring-summer 1-1.5' summer 2.5' spring-summer 6-18" spring 1-2.5' late spring-summer 1-1.5' midsummer 2-3' summer-fall 1.5' spring-fall 1.5' late spring-early summer 6"-3' early-late summer 2' summer 1' summer-fall

69

bird green roof Hummingbirds are the primary birds which play a role in pollination in North America. Their beaks and tongues are very long and they draw nectar from tubular flowers. Pollen is carried on the beaks and feathers of different hummingbirds (Forest, 2013).

To keep birds coming, create a living smorgasbord that includes plants with berries, foliage, fruit and nectar. Mix up natives and non-natives and include plants that bloom at different times of the year. Birds also need leafy or twiggy shrubbery to protect them from predators and to provide nesting places.

Six bird focal species were chosen for purpose of this design and study.

Anna’s hummingbird, house finch, western scrub-jay, bushtit, western blue-bird and house sparrow are these focal species. Bright colored tubular flowers attract hummingbirds to gardens. Hummingbirds are able to see the color red; bees cannot.

70 design

NG

Y MA

SUMM

JUN

N OCT

AUTU ER

APR

UG

MAR

SPRI

SEP

MN

ER

A

JUL

start bloom time: summer Agastache rupestris Asclepias tuberosa Coreopsis grandiflora Cosmos bipinnatus Echinacea spp.

Eriogonum flavum Gaillardia pulchella Gladiolus tristis Lobelia laxiflora Monarda spp.

Phygelius spp.

Scabiosa atropurpurea Solidago ‘Cascade Creek’ Tagetes spp.

F

WINT

EB

bird vegetation diagram

JAN

DEC

OV

start bloom time: spring Aquilegia spp.

Clarkia concinna Eschscholzia californica Lupinus densiflora Mimulus aurantiacus Nigella damascena Penstemon heterophyllus Salvia officinalis Veronica spp.

Zinnia grandiflora year-round Lobularia maritima

above Bird chart showing the genus and species of chosen plants, blooming season, and

success in achieving bird conservation and to increase accountability.

color of inflorescence. left Anna’s hummingbird, house finch, western scrub-jay, bushtit, western bluebird, house sparrow. The goal of the focal species strategy is to measure the

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boulders

log

fruit plants nectar plants

72 design

Bird planting plan

Plant Symbol Scientific Name AA AT CG CB EF EC HP KU LM LD MA ND PR SG SA SC ZC

Aloe aristata Asclepias tuberosa Coreopsis grandiflora Cosmos bipinnatus sonata Eriogonum flavum Eschscholzia californica Hesperaloe parvifolia Kniphofia uvaria 'Nancy's Red' Lobularia maritima Lupinus densiflora Mimulus aurantiacus Nigella damascena Phygelius x rectus Salvia greggii and Salvia x jamensis Scabiosa atropurpurea Solidago 'Cascade Creek' Epilobium canum

Common Name Sun Exposure

Watering Height Width Blooms Needs

Color

Type

full sun/part shade full full full Wild buckwheat full California poppy full Coral yucca full full Sweet alyssum full Lupine full Sticky monkey flower full Love-in-a-mist full sun/part shade Cape fuschia full sun/part shade autumn sage full sun/part shade Pincushion flower full Goldenrod full sun/part shade California fuschia full

low-medium medium low-medium medium low-medium low-medium very low-low low medium very low very low medium medium low low-medium low very low-low

red white yellow white yellow orange pink red white purple orange purple pink red dark purple yellow red

succulent perennial perennial annual perennial perennial shrub perennial annual annual perennial annual perennial shrub perennial perennial shrubby perennial

Butterfly weed

8-10" 3' 1-2' 1.5-2' 10" 1' 3-4' 2' 1' 1.5-2' 4.5' 1-1.5' 2' 1-4' 2.5-3' 2-3' 6"-4'

8-10" 1' 3' 1.5-2.5' 8" 1.5' 3-4' 2' 1' 1.5-2' 4.5' 10" 3' 1-4' 1' 1-2' 3-4'

midwinter-summer summer summer summer-fall early summer spring-summer summer-fall early-midsummer all year spring spring-summer spring summer-fall spring-fall summer summer-fall late summer-fall

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hybrid green roof There are a lot of opportunities for wildlife to forage and nest on a small green roof, although much of it will be on the micro scale. The diversity of invertebrate species is a good indicator of the ecological health of a green roof. There has been some research done on biodiversity and it has been focused on certain families and orders, notably beetles, spiders, and the Hymenoptera (bees, wasps, and ants) (Dunnett et al., 2011). Invertebrates are very mobile and can colonize green roofs easily, but many other animals are also attracted to green roofs and will colonize from some distance.

The design of ‘the hybrid’ green roof focused on the attraction of butterflies, bees, and birds. Design elements from all three green roofs (butterflies, bees, birds) were taken into consideration for the design of the hybrid. It is important to note that alternatives to sedum mats are introduced. These alternatives include using native plants and mimicking natural habitats to incorporate microhabitats that are customized for butterflies, bees, and birds. Scattered rocks, dead wood, bee farms and more diverse vegetation are incorporated. This hybrid green roof design and research suggest that if suitable niches are provided on green roofs, plants and animals will move in rapidly and establish communities. Customized green roofs can even provide habitat for declining and endangered species, suggesting that they have the potential to be an essential tool in species conservation.

74 design

DEC

APR

NG JUN

SUMM JUL

OCT

SEP

MAR

AUTU ER

F

SPRI

UG

JAN

WINT

ER

A

start bloom time: summer Achillea millefolium Aster 'Purple Dome' Dasylirion wheeleri Asclepias fascicularis Echinacea spp.

Hesperaloe parvifolia Origanum 'Betty Rollins' Sedum spp.

Solidago 'Cascade Creek' Sphaeralcea ambigua Eriogonum nudum 'Ella Nelson's Yellow' Zauschneria californica Kniphofia uvaria 'Nancy's Red'

MN

Y MA

V NO

EB

hyrbid vegetation diagram

start bloom time: spring Erigeron karvinskianus Eschscholzia californica Lupinus densiflora Penstemon heterophyllus Salvia greggii and Salvia x jamensis Gilia tricolor Nepeta x faassenii Teucrium cossonii 'Marjoricum' Aloe aristata

above Hybrid green roof chart showing the genus and species of chosen plants, blooming season, and color of inflorescence.

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bare earth

boulders log

climbing vine bee farms

76 design

Hybrid planting plan

Plant Symbol Scientific Name

Common Name

Sun Exposure

Watering Height Width Blooms Needs

Color

Type

Form

Pollinator

AM AF AP DW E EK EN EC GT HP KU LD NF OB PH SG SG SC SA TC ZC

Common Yarrow Narrow leaf milkweed Purple dome Michaelmas Desert spoon Coneflower Santa Barbara Daisy Naked buckwheat 'Ella Nelson's Yellow' California poppy Bird's eyes Coral yucca

full full full full full full full full full full full full full sun/part shade full full sun/part shade full sun/part shade full full sun/part shade full full full

very low very low low-medium very low-low low-medium low low low-medium low-medium very low-low low very low low low low low low low low low very low-low

white white purple white white white yellow orange purple pink red purple purple pink deep blue red pink yellow orange purple red

perennial perennial perennial shrub perennial perennial perennial perennial annual shrub perennial annual perennial perennial perennial shrub perennial/succulent perennial perennial groundcover shrubby perennial

umbel buttons and globes daisy leaves shape daisy daisy buttons and globes daisy daisy spire, leaves shape spire spire spire leaves shape spire screens and curtains umbel plume daisy umbel screens and curtains

butterflies, beneficials butterflies butterflies, beneficials beneficial insects butterflies, bees butterflies, beneficials bees butterflies, bees, birds butterflies birds birds butterflies, birds bees butterflies, bees butterflies, bees birds, beneficials butterflies, bees butterflies, birds, beneficials bees bees birds

Achillea millefolium Asclepias fascicularis Aster 'Purple Dome' Dasylirion wheeleri Echinacea Erigeron karvinskianus Eriogonum nudum 'Ella Nelson's Yellow' Eschscholzia californica Gilia tricolor Hesperaloe parvifolia Kniphofia uvaria 'Nancy's Red' Lupinus densiflora Nepeta x faassenii Origanum 'Betty Rollins' Penstemon heterophyllus Salvia greggii and Salvia x jamensis Sedum spp.

Solidago 'Cascade Creek' Sphaeralcea ambigua Teucrium cossonii 'Marjoricum' Epilobium canum

Lupine Hybrid catmint Dwarf oregano Foothill penstemon Autumn sage Sedum 'Autumn Joy' Goldenrod Apricot mallow Fruity germander California fuschia

3’ 2-4’ 2' 3-5' 2-3' 10-20" 10" 1' 4-18" 3-4' 2' 1.5-2' 2-3' 3-6" 1-1.5' 1-4' 2-5" 2-3' 3-4' 8" 6"-4'

2’ 2' 4-5' 2-3' 3' 8" 1.5' 9" 3-4' 2' 1.5-2' 2-3' 1-1.5' 2.5' 1-4' 1-1.5' 1-2' 2-3' 1.5' 3-4'

summer-early fall summer late summer-early fall spring-summer summer spring-fall early summer spring-summer late spring-early fall summer-fall early-midsummer spring late spring-summer summer spring-summer spring-fall midsummer summer-fall summer-fall late spring-early summer late summer-fall

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butterfly green roof Gilia tricolor Lobularia maritima Echinacea spp.

Sorghastrum nutans Dasylirion wheeleri Penstemon heterophyllus

78 design

Eschscholzia californica Sedum spp.

bee green roof Thymus x citriodorus Echinacea spp.

Cerinthe major ‘Purpurascens’ Origanum ‘Betty Rollins’

bird green roof

hybrid green roof

Aloe aristata Nigella damascena Epilobium canum Hesperaloe parvifolia Solidago ‘Cascade Creek’ Lupinus densiflora

Sedum spp.

Echinacea spp.

Epilobium canum Dasylirion wheeleri Hesperaloe parvifolia Erigeron karvinskianus

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80 design

1

HYBRID SHIPPING CONTAINER GREEN ROOF NTS

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conclusion

synopsis Ensuring that pollinators have adequate foraging resources is important for maintaining the health of ecosystems. Green roofs can play an important role in bioregional biodiversity design approaches by forming linkages for green networks or greenways that interconnect natural or vegetated open space. The Arboretum Teaching Nursery has many pollinator friendly gardens surrounding it that attract beneficial wildlife and insects. By creating linkages or “wildlife stepping stones� we can heavily influence biodiversity and eliminate the ongoing loss of habitat so that these new green roofs can serve as refuges or shelters for wildlife in years to come.

84 conclusion

references Administration, U. S. G. S. (2011). The Benefits and Challenges of Green Roofs on Public and Commercial Buildings.

Hopkins, G., & C., G. (2011). Living Architecture: Green Roofs and Walls: CSIRO Publishing.

Anderson, B. (2010). In Our Own Back Yard: A History of the UC Davis Arboretum. UC Davis Magazine.

Köhler, M. (2005). Long-Term Vegetation Research on Two Extensive Green Roofs in Berlin. Urban Habitats, 4, 3-26.

Ansel, W. (2012). A Quick Guide to Green Roofs. IGRA (International Green Roof).

Mentens, J., Raes, D., & Hermy, M. (2006). Green roofs as a tool for solving the rainwater runoff problem in the urbanized 21st century?

Landscape and Urban Planning, 77(3), 217-226. doi: http://dx.doi. org/10.1016/j.landurbplan.2005.02.010

Breuning, J. (2008). Where Beetles are Crawling and Honeybees are Humming. Sixth Annual greening Rooftops for Sustainable Communities, 1-10.

“California Academy of Sciences, San Francisco, Ca, U.S.A.” Designing our Future: Sustainable Landscapes (2014). Print.

Castaneda, A., & Truan, M. (2006). UC Davis Arboretum Wildlife Management and Enhancement Plan (AWMEP). UC Davis Museum of WIldlife and Fish Biology Biomonitoring Program, 2-65.

Castleton, H. F., Stovin, V., Beck, S. B. M., & Davison, J. B. (2010). Green roofs; Building energy savings and the potential for retrofit. Energy and Buildings, 42, 1582-1591. doi: 10.1016/j.enbuild.2010.05.004 Dakin, K., Benjamin, L. L., & Pantiel, M. (2013). The Professional Design Guide to Green Roofs. Portland, Oregon: Timber Press, Inc. .

Dunnett, N., Gedge, D., Little, J., & Snodgrass, E. C. (2011). Small Green Roofs: Low-Tech Options for Greener Living. Portland, Oregon: Timber Press, Inc.

Oberndorfer, E., Lundholm, J., Bass, B., Coffman, R. R., Doshi, H., Dunnett, N., Rowe, B. (2007). Green Roofs as Urban Ecosystems: Ecological Structures, Functions, and Services. BioScience, 57(10), 823-833. doi: 10.1641/B571005 Oudolf, P., & Kingsbury, N. (1999). Designing with Plants. Portland, Oregon: Timber Press, Inc. Philippi, P. M. (2005). Introduction to the German FLL: Guideline for the Planning, Execution and Upkeep of Green Roof Sites.

UC Davis Arboretum. (2015). 2015, from http://arboretum.ucdavis.edu/ Vijayaraghavan, K., & Joshi, U. M. (2014). Can green roof act as a sink for contaminants? A methodological study to evaluate runoff quality from green roofs. Environmental Pollution, 194, 121-129. doi: 10.1016/j. envpol.2014.07.021

Forest, M. (2013). Selecting Plants for Pollinators: A Regional Guide for Farmers, Land Managers, and Gardeners in the California Dry Steppe Province. Retrieved from pollinator.org 85

plant directory This selection covers the plants used in the research of this study. All the plants used in this project are suitable for use in California’s Central Valley, Zone 9 which is characterized by being hot and dry in the summer, and occasionaly filled with a deep, thick radiation fog in winter.

sun exposure during hot summer months.

abbreviations

Low Water deeply every two weeks during the dry season.

General

Medium Water deeply once a week during the dry season.

spp.=species (plural)

Type

Height

Perennial long-lived, soft-stemmed plants that do not form woody branches. Many perennials need seasonal care such as removing spent blossoms or cutting back dormant stems to the ground.

Plant height varies greatly between different growing conditions.

Width The approximate diameter of the bulk of the plant’s foliage at its widest point after three years, NOT the spread of the base of the plant.

Sun Exposure Full Sun Plant requires direct sunlight for most of the day Full Sun or Part Shade Plant will do well in direct sunlight for most of the day or shade for part of the day. Plant can tolerate exposure to hot afternoon sun.

Part Shade Plant will do well in dappled shade. Plant will tolerate sun exposure in the morning but must be protected from hot afternoon sun.

Part Shade or Shade Plant will do well in dappled shade or full shade.

Plant will tolerate sun exposure in the morning but must be protected from hot afternoon sun.

Shade Plant requires full shade. Plant will do best if it never gets direct 86 conclusion

Watering Needs Very Low water deeply once a month during the dry season.

Annual a plant that completes its life cycle, from germination to the production of seed, within one year, and then dies.

Groundcover low-growing plants that can spread to cover a wide area.

Shrubs woody plants that stay below 15 feet tall. Tend to have deeper root systems than perennials and many boast showy flowers.

Form (please see pages 48-55 for more information)

Scientific Name

Common Name

Achillea millefolium Agastache rupestris Aloe aristata Ammi majus Asclepias fascicularis Asclepias tuberosa Aster 'Purple Dome' Aster x frikartil Cerinthe major 'Purpurascens' Coreopsis grandiflora Cosmos bipinnatus Cosmos bipinnatus sonata Dasylirion wheeleri Echinacea Erigeron karvinskianus Eriogonum flavum Eriogonum nudum 'Ella Nelson's Yellow' Eschscholzia californica Gaura lindheimeri Gilia tricolor Hesperaloe parvifolia Kniphofia uvaria 'Nancy's Red' Lobularia maritima Lupinus densiflora Mimulus aurantiacus Nepeta x faassenii Nigella damascena Origanum 'Betty Rollins' Penstemon heterophyllus Phacelia campanularia Phygelius x rectus Salvia greggii and Salvia x jamensis Salvia officinalis Scabiosa atropurpurea Sedum (most) Sedum sp.

Sidalcea malviflora Solidago 'Cascade Creek' Sorghastrum nutans Sphaeralcea ambigua Teucrium chamaedry's 'Nanum' Teucrium cossonii 'Marjoricum' Thymus praecox arcticus Thymus x citriodorus Epilobium canum Zephyranthes candida

Common Yarrow Licorice mint

Sun Exposure

full sun full sun/part shade full sun/light shade Bishop’s lace full sun/part shade Narrow leaf milkweed full sun Butterfly weed full Purple dome Michaelmas full full Honeywort full sun/light shade full full full Desert spoon full Coneflower full Santa Barbara Daisy full Wild buckwheat full Naked buckwheat 'Ella Nelson's Yellow' full California poppy full full Bird's eyes full Coral yucca full full Sweet alyssum full Lupine full Sticky monkey flower full Hybrid catmint full sun/part shade Love-in-a-mist full sun/part shade Dwarf oregano full Foothill penstemon full sun/part shade California desert bluebells full Cape fuschia full sun/light shade autumn sage full sun/light shade Garden sage full Pincushion flower full Stonecrop full Sedum 'Autumn Joy' full Checkerbloom full Goldenrod full sun/light shade Indiangrass full Apricot mallow full Dwarf germander full sun/light shade Fruity germander full Mother of thyme full Lemon thyme light shade California fuschia full Argentine rain lily full sun/light shade

Watering Needs Height Width Blooms

Color

Type

Form

very low medium low-medium low-medium very low medium low-medium medium medium low-medium medium medium very low-low low-medium low low-medium low low-medium medium low-medium very low-low low medium very low very low low medium low low low-medium medium low low-medium low-medium low-medium low medium low very low low very low-low low low low-medium very low-low very low-low

white pink red white white white purple purple purple yellow white white white white white yellow yellow orange white pink purple pink red white purple orange purple purple pink deep blue deep blue pink red purple dark purple white pink pink Yellow green orange purple purple purple white red white

perennial perennial succulent annual perennial perennial perennial perennial perennial perennial annual Annual shrub perennial perennial perennial perennial perennial perennial annual shrub perennial annual annual perennial perennial annual perennial perennial annual perennial shrub perennial perennial perennial/succulent perennial/succulent perennial perennial perennial grass perennial groundcover groundcover groundcover shrubby perennial shrubby perennial perennial

umbel spire spire, leaves shape umbel buttons and globes umbel daisy daisy buttons and globes daisy daisy daisy leaves shape daisy daisy buttons and globes buttons and globes daisy screens and curtains daisy spire, leaves shape spire daisy spire daisy spire screens and curtains leaves shape spire daisy screens and curtains screens and curtains spire buttons and globes umbel umbel daisy plume plume daisy spire umbel umbel leaves shape screens and curtains daisy

3’ 1.5-2.5' 8-10" 1-3’ 2-4’ 3' 2' 2' 2' 1-2' 1.5-2' 1.5-2' 3-5' 2-3' 10-20" 10" 10" 1' 3-4' 4-18" 3-4' 2' 1' 1.5-2' 4.5' 2-3' 1-1.5' 3-6" 1-1.5' 6-18" 2' 1-4' 1-3' 2.5-3' 2-5" 2-5" 2' 2-3' 3-4' 3-4' 8" 8" 1-3" 6-12" 6"-4' 1'

summer-early Fall midsummer-midautumn midwinter-summer Summer summer summer late summer-early fall late summer-early fall spring to fall 3' summer 1.5-2.5' summer-fall 1.5-2.5' summer-fall 4-5' spring-summer 2-3' summer 3' spring-fall 8" early summer 8" early summer 1.5' spring-summer 3-4' late spring-fall 9" late spring-early fall 3-4' summer-fall 2' early-midsummer 1' all yr.

1.5-2' spring 4.5' spring-summer 2-3' late spring-summer 10" spring 1-1.5' summer 2.5' spring-summer 6-18" spring 3' summer-fall 1-4' spring-fall 1-2.5' late spring-summer 1' summer 1-1.5' midsummer 1-1.5' midsummer 2' early spring 1-2' summer-fall 1.5' midsummer 2-3' summer-fall 1.5' spring-fall 1.5' late spring-early summer 6"-3' early-late summer 2' summer 3-4' late summer-fall 1' summer-fall 1.5' 8-10" 1’ 2’ 1' 2' 2'

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thank you

wildlife stepping stones: a study of biodiversity on green roofs

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