Mitigating Habitat Loss Through Green Roof Design Kristine Kopia, MLA Candidate 2014
Table of Contents Introduction | 01 Proposal 02 Green Roofs 03 Songbirds 04
Case Studies | 05
Tallgrass Prairie and Wetland Habitats Habitat Restoration and Ecological Stewardship Urban Tidal Marsh Habitat Zurich Main Station Klinikum 2 John Deere Works
07 09 12 14 16 18
Design | 21
Site / Roof Selection Plant Palette, Benefits, and Design Roof Design Lathe House Observation Roof
Closing Remarks Author Thanks Bibliography Image Sources
23 24 30 32 33
| 37 | 39 | 40 | 41
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Urban areas cover 2.7 of the world’s surface and, since 2008, are inhabited by the majority of the human population (Strohbach et. al 2009). It is predicted that by 2030 more than 60% of the world population will live in cities (Miller 2005). With more people wanting to live in cities, as well as population increase, comes the need for more living space. This means cutting into the natural landscape to build houses, apartments, shopping malls, and parking lots. The process of urbanization generally leads to an environment that is favorable for humans, but 2
Introduction
also to many environmental problems, including the loss of biodiversity. Urbanization decreases biodiversity (Strobach et. al 2009). When we urbanize, habitats can become fragmented or non-existent. Cities try to remedy this by creating green space and parks, but these spaces do not guarantee an increase in diversity. But cities do possess a level of biodiversity, and recent literature shows that there is more than previously thought. Urban structures can provide a wide range of habitats depending on the intensity of urbanization. They often contain bits and pieces of natural or semi-natural ecosystems (Strobach et. al 2009). In cities, these spaces can include systems that filter air, regulate micro-climate, reduce noise, drain rainwater, and treat sewage (Bolund and Hunhammar 1999).
Machinery removing trees before construction 1
Proposal: To increase and enhance biodiversity in cities, I am proposing a design that implements habitat loss mitigation strategies onto green roofs. Mitigating habitat loss is important for a multitude of reasons. Repairing a site that was disturbed can create space for future use: these habitats can be used by visiting organisms, and can be observed by biologists, ecologists, nature-lovers, and other residents of the buildings around the roofs. Habitat restoration impacts human health. For example, healthy forests and riparian zones help maintain clean drinking water and control floods. Having good water quality increases fish and amphibian populations. Lastly, nature is a thing of beauty. By mitigating habitat loss we can accomplish two things: increase wildlife in disturbed areas for people to enjoy and increase the aesthetic properties that nature has to offer so that millions of people live a mentally healthier life (Hill 2000). Because more people live in cities, a disconnect is created by humans and nature (Miller 2005). According to the United Nations Population Division, as of 2003 approximately 48% of people in the world live in urban areas. This figure is predicted to surpass 60% by 2030 (UN, 1997). Some developed countries have already exceeded this figure. In the USA, around half the population lives within the suburbs with an additional 30% living in urban areas (Miller 2005). As more people choose to live in urbanized areas, more of the landscape is used to accommodate the new population, thus decreasing the natural landscape and the biodiversity within it. There is no real opportunity to see nature when you are surrounded by buildings and high rises. There needs to be more of an effort to design places that provide more opportunities to see and interact with nature (Miller 2005). An example of this is the High Line, the one-mile greenway in New York City that provides people with an educational walk through native plantings and a chance to see organisms that have decided to call the greenway their home (Chrisman et al. 2005). Creating these habitats on roofs would allow people the same 2
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Volunteers planting new grass during a habitat restoration project 4
Bird watchers in the winter 5
Tree gates keeping people from disturbing the vegetation
opportunity to immerse themselves in a pocket of nature, or to see nature from the windows of their apartments. These roofs bring in nature that was absent before that can be observed at varying levels, while providing some of the ecosystem services previously mentioned.
The Chicago City Hall green roof helps cool the building and minimize water run-off
Why green roofs? Green roofs have been used since 4000 BC. In the past, green roofs were used to create sacred places and gardens. In the modern world, these structures have other uses. Green roofs reduce pollution and urban heat islands, mitigate stormwater runoff, and maximize the utilization of urban land (Weiler and Scholz-Barth 2009). They can also help reduce energy consumption. A green roof can decrease building temperature by 68 degrees Fahrenheit (20 degrees Celsius), and can cut down on air conditioning energy between 25% and 80% (Saadatian et. al, 2013).
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Recent literature discusses how green roofs are becoming a means of habitat loss mitigation, specifically for birds. Research shows that birds come to green roofs in search of food. Green roofs provide the space for many habitat components that would attract birds such as water, cover, and most importantly food (Fernandez-Canero and GonzalezRedondo, 2010).
Green roofs used as habitats provide open, flat green space, which is limited on the ground level. This allows for more biodiversity in urban areas. Using multiple roofs will maximize green space and extend habitat. Along with having energy-saving benefits, green roofs are an optimal way to mitigate habitat loss in urban areas.
Green roof on the Bronx County Courthouse in New York City
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Songbirds The target of this design is to provide habitat for songbirds because they have been in decline. According to the North American Breeding Bird Survey, there was an 18% decrease in birds between 1966 and 2005. Resident species decreased by 30% and migrant species decreased by 19% in both the United States and Canada (Valiela and Martinetto 2007). Many species of birds in the songbird group have suffered overall declines of 30% to 70% in the last 40 years in New Jersey, New York, Maryland, and other eastern states (Detjen 1990). Many factors contribute to the decline of songbird population. One is the disappearance of open fields and meadows where they mate, nest, and gather food. Another factor is fragmented forest lands. Some songbirds prefer to nest deep within forest interiors, but due to suburban sprawl, highways, and other developments, forests have been severely fragmented and do not offer the same safety for songbirds as they once did (Carney 1985). Nest robbing predators like raccoons and squirrels, as well as outdoors cats, have also caused a threat to many songbirds (Detjen 1990). By replicating songbird habitat on roofs, many of the problems that threaten songbird decline could be addressed. Roofs are out of reach to many predatory animals. There are no worries of raccoons or squirrels stealing eggs from nests, and we would most likely not find cats at such a high elevation. If planted correctly, these roofs could provide birds 10
Wild turkeys cross the road to get from one forested area to another 4
with all the essentials they need to survive, from food to nesting materials. The roofs can be used as stop off points for migrating birds as well as provide food for birds that do not migrate, and nesting sites for birds in the spring and summer. Having these roofs would not only encourage bird presence, but increase biodiversity in cities.
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Case Studies
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Cedar Waxwings nesting in a newly restored habitat The American Goldfish, state bird of New Jersey 9
Forest fragmentation due to roads and farm land
The consideration of these case studies serves two purposes. The first is to explore the strategies used in habitat restoration for various sites. This is important to first understand the many approaches to restoring habitats in varying environments. For example, habitat restoration in a meadow will most likely be different than habitat restoration in a wetland. Once these approaches are examined, it is my hope to apply them to green roof design. The second purpose is to see how some green roofs have been designed to provide habitat for various species of animals and plants. Oftentimes a building (or buildings) are constructed that negatively impact neighboring ecosystems. Some green roofs have been designed to not only benefit the building, but benefit those ecosystems that the building has disturbed by creating more habitat space. It is important to research green roofs that have habitat designs incorporated into them to see that it is possible to recreate habitats in urban areas and how successful these roofs are at bringing in biodiversity. The first group of case studies describes various sites of general habitat restoration. These sites are located in New Jersey and describe different landscapes that have undergone habitat restoration. Duke Farms has restored a few different types of habitats through the implementation of Ecological
Stewardship. The Meadowlands in Hackensack discusses restoration in two tidal marshes. The Eagle Lake Wetland Complex discusses changes in breeding bird populations due to habitat restoration. All three sites vary in size, the smallest being the Meadowlands sites (79 and 140 acres) and the largest being Eagle Lake Wetland Complex (38,000 acres). The second group demonstrates how the roofs were used to restore habitat that was potentially lost by a building’s presences. The smallest green roof is the John Deere Works roof in Mannheim, Germany (450 square ft.) and the largest is the Zurich Main Station in Zurich, Switzerland (107,640 square ft.). Although the last green roof case study, the John Deere Works building, does not restore habitat, it successfully demonstrates how a wetland can be recreated on a flat roof. Researching these case studies informs the design process for the chosen site and reinforces the decisions made in designing for the site. After understanding the various strategies of habitat restoration within my chosen sites, I hope to emulate what has been done by applying these strategies to green roofs. Investigating green roofs that have already recreated habitats will help reinforce my design by showing that it is possible to accomplish what I aim to do. 5
Tallgrass Prairie and Wetland Habitats
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Site:
Eagle Lake Wetland Complex
Location:
Hancock and Winnebago counties, Iowa
Site Size:
38,000 acres
Date:
1999-2001 breeding seasons
Client:
Clear Lake Wildlife Unit
Landscape Architect/Designer: Managed By:
Iowa Department of Natural Resources
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Aerial of Eagle Lake Wetland Complex
View into the wildlife refuge at Eagle Lake Wetland Complex
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Over the past 2 centuries, native tallgrass prairie and 19 wetlands have been lost. In turn, bird populations that utilize these habitats have also experienced decline. The process of restoring tallgrass prairie and wetlands began to help conserve bird communities. Both state and federal agencies have started to restore Midwestern grassland and wetland habitats (Bishop et al., 1988). Bird surveys (upland and wetland bird populations) were conducted between a 2-year period to see if restoration had positive effects on breeding bird populations (Fletcher and Koford, 2003). The Eagle Lake Wetland Complex had to undergo a few different techniques during the restoration process. The grasslands were restored by working with warm-season and cool-season grass plantings that were already present on site. The wetlands were restored by plugging tile lines and drainage ditches as well as excavating wetland basins to increase wetland depth (Fletcher and Koford, 2003). Approximately 3,322 bird observations were made between 1999 and 2001: 1630 in restored grasslands, 740 in restored wetlands, 531 in pastures, 253 in haylands, and 168 in rowcrop fields, all of which encompassed a total of 54 bird species. After restoration, 16 bird species increased and 4 bird species decreased. Due to the grassland and wetland restoration, more breeding habitat was provided for grassland and wetland-nesting birds (Fletcher and Koford, 2003).
Habitat Restoration and Ecological Stewardship Site:
Duke Farms
Location:
Hillsborough, New Jersey
Site Size:
2,470 acres
Date:
Began in 1893, current mission adopted in 2006, most recent projects completed in 2012
Client:
Duke Farms Foundation
Landscape Architect/Designer:
Andropogon and Associates
Managed By:
Duke Farms Foundation
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The Sedge Wren, a grassland breeding bird, saw an increase in population after restoration 20
Why I chose this case study One aspect of successful restoration is creating more space for birds to utilize, specifically for breeding. As mentioned before, the restoration successfully provided more breeding habitat for birds found on site. By allowing more breeding sites, it is expected that birds will continue to use the site. This encourages the return of said birds at a later date to breed and nest.
The Swamp Sparrow saw an increase in population after restoration Aerial of Duke Farms 8
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Off route 206 in Hillsborough, New Jersey is Duke Farms, a large site that contains a variety of habitats and park-like areas for people to explore. Originally constructed by J. B. Duke as the grounds for his estate, the once agricultural and wooded landscape was transformed into a charming park with 9 artificial lakes, 2.5 miles of stone walls, and 45 structures. J. B. Duke’s daughter, Doris Duke, inherited the land when he passed away. She obtained surrounding land around the estate to protect it from suburban sprawl. When she died in 1993, she wrote in her last will and testament that she wanted the estate to be preserved and the wildlife protected, only to be used for horticulture, agriculture, and research. This eventually led to the Duke Farms’ primary objective of environmental stewardship (DFF “Duke Farms”). Duke Farms took many steps in their habitat 23
restoration process. First they had to understand the existing site conditions. This helped to inform the regeneration process. Once this was done, they could begin managing the wildlife. Part of this management included working to remove invasive species. Invasive wildlife can impede on and compete with native animals and their habitats. To help native species acquire the necessary resources they need to survive, Duke Farms began to remove invasive species. Native vegetation was planted once the desired level of invasive control was reached. The last step in the initial process is monitoring and maintaining. Habitat restoration efforts require maintenance so that invasive species that have been removed are kept in check (DFF “Duke Farms”).
The habitat conservation targets at Duke Farms include grassland, forest, open wetlands, and pollinator meadows. Within these habitats are 72 species conservation targets, the majority of them birds that require grassland, shrub-scrub, or forest habitats. Some of these birds consist of songbirds such as the Black-throated blue warbler, the Chipping sparrow, the Scarlet tanager, and the Dickcissel, all of which have been spotted on site post-restoration (DFF “Duke Farms”). Why I chose this case study: Duke Farms exemplifies the act and principles of Ecological Stewardship. They maintain the land that was given to them with care and help to make sure it says managed. Not only does the foundation care for the ecological aspect of the land, but also the educational aspect. A great deal of effort goes into making sure the visitors of Duke Farms are aware of what is going on around them. There are informative displays within the Visitors Center as well as along the trails which bring people on a journey throughout the site. These displays describe in detail the steps taken to restore all the habitats within the grounds, as well as the unique species of plants and animals that thrive within them. This educational element is important for design because it helps people to understand and stay aware of the environment around them.
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Volunteers at Duke Farms removing Japanese Barberry (Berberis thunbergii) 25
The Native Plant Nursery at Duke Farms 26
Volunteers planting native plants from Duke Farm's Native Plant Nursery
Diagram created by Duke Farms showing their restoration proccess
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Urban Tidal Marsh Habitat Sites:
Harrier Meadow, Mill Creek
Location:
The Meadowlands, New Jersey
Site Sizes:
79.5 acres, 140.1 acres
Client/Designer:
New Jersey Meadowlands Commission
Managed By:
New Jersey Meadowlands Commission
Restoration Dates:
1998-1999
Observation Dates:
1997 - 2002
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Aerial of Harrier Meadow 12
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Aerial of Mill Creek
The goal of this project was to monitor bird response to the restoration of Harrier Meadow and Mill Creek, two tidal marshes located in the New Jersey Meadowlands District, NJ. Harrier Meadow is surrounded by tidal mudflats, urban development, and landfills, while Mill Creek is bordered by the New Jersey Turnpike and residential land use. Both sites have experienced degradation due to their proximity to urbanized regions. As each tidal marsh declined in quality, bird community compositions suffered. According to the authors of this study, there is not much documentation on avian response to habitat restoration in urbanized areas. To this end, the project sought to conduct a survey that would start one year prior to restoration and three years post-restoration to measure species richness, abundance, and evenness for both sites (Seigel et al. 2006).
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Harrier Meadow 30
Harrier Meadow and Mill Creek had similar restoration design. Both tidal marshes were observed to be dominated by Phragmites autrailis and other invasive vegetation such as Lythrum salicaria (purple loosestrife), and had an absence of open water; only Mill Creek small, fragmented bodies of water were present. The restoration designs were meant to create more open-water areas that were tidally influenced, tidal channels, and mudflats, and well as add high-marsh positively affected the avian community. The and upland vegetation (Seigel et al. 2006). strategies used in this kind of habitat restoration will differ from grassland restoration, so it is important In 1998, 22 hectares (71%) of Harrier Meadow was to see how the various strategies of healing the land restored, and in 1999, 38 hectares (67%) of Mill can still increase biodiversity once the environment Creek was restored. Both tidal marshes experienced improves. According to the study, many songbirds an increase in species richness and abundance, and were observed at the sites, some with populations a decrease in evenness. The changes in the bird that are documented to be in decline such as communities at both sites echoed the changes made the Cedar waxwing, Barn swallow, Common to the habitat through restoration. By increasing yellowthroat, Baltimore oriole, and Indigo bunting habitat heterogeneity and adding more open-water (NJ Audubon Society). habitat through restoration, the number of bird species and bird abundance increased (Seigel et al. 2006). Why I chose this case study: Tidal marshes and wetlands are unique places that attract various types of bird species that a grassland or forest may not. This study is a perfect example of how the tidal marsh landscape, when repaired, 13
Zurich Main Station Project Name:
Zurich Main Station
Location:
Zurich, Switzerland
Date:
2002
Client/Developer:
SBB Swiss Federal Railways
Landscape Architect/Designer:
Ernst Basler + Partner Ltd.
Consultants/Architects:
Pool Architect
Type:
Semi-extensive
Size:
107,640 sq. ft.
Soil Depth:
1.6-7.9 in.
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Aerial of Zurich Main Station 14
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Construction workers on the new green roofs
The Zurich Oerlikon railway station is located in Oerlikon in the city of Zurich, Switzerland. The railway opened in 1855, was rebuilt in 1912, and is owned by Swiss Federal Railways. There are 6 platforms, 6 tracks, and receives 110,000 daily passengers (wiki, find source). The Zurich train station needed the aid of 4 additional platforms to accommodate more passengers. However, there were two challenges to overcome in order for this to happen. The first challenge was that the train station was already part of the dense portion of the city, so space was limited. With the constant rail traffic, construction would be difficult. The second challenge was that the land the station was built on was marked as habitat for a variety of insects and a rare species of lizard, the Wall Lizard (Podarcus muralis). The Wall Lizard prefers desert-like spaces and had adapted to the gravel covered ground between the railway tracks. According to Swiss law, the demolition of animal habitat without replacement is prohibited (Cantor 2008). The solution was to recreate the habitats of the insects and lizards on the roofs of the new platforms. These green roofs not only give shade to the thousands of passengers during the hot summer, but contribute to the habitat the insects and lizards utilize. For the less mobile species, a series of planted fences and gabion cages were put into place, giving insects and lizards the ability to climb from the ground and onto the roof. The designers also added small areas of refuge like old wooden branches and stone plates for the lizards so they had a shady place to hide during the hot summers (Chrisman et al. 2005). To date, the roof has been established as a successful habitat for insects and the Wall Lizard, which is rare north of the Swiss Alps. The main station has one of the biggest populations in the northern part of the Alps. Initially, there was worry that the vibrations of the trains would disturb the lizards. However, it was observed that the lizards never ran from the incoming trains when they lived between the tracks. Now, more study is being
conducted on how to attract more of these lizards. Overall, the Zurich station green roof has been well established (Cantor 2008). Why I chose this case study: This is another example of how a green roof was used to accommodate for habitat loss. I believe the way in which they remade the Wall Lizard’s habitat was unique and effective. While the train station may be busy during the majority of the day, the lizards (and other insects that have been found on site) have the ability to move around without much disturbance. This project is also a good example of how various species can adapt to their surroundings and to the disturbances within them given the opportunity to do so. By creating the vegetated fences and walls, the lizards can roam onto and off of the roof with ease. Creating this connection allows their habitat to double in size, between the ground and the roof, and gives them a chance to escape the moving trains should they need to take refuge in a quieter place. 33
View of the tops of the platforms 34
View of the plantings on the platform roofs 15
Klinikum 2 Project Name:
Klinikum 2, Cantonal Hospital of Basel
Location:
Basel, Switzerland
Date:
2003
Client/Developer:
University Hospital of Basel
Landscape Architect/Designer:
Stephan Brenneisen
Type:
Extensive
Size:
32,280 sq. ft.
Soil Depth:
3.5 in
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Clinic 1 (Klinikum 1), originally built in 1937, received the addition of green roofs on most of its buildings by 1990. These green roofs were installed for recovering patients: instead of observing flat, grey roofs, the patients had a view of beautiful green space outside their rooms. Clinic 2 (Klinikum 2), built in 1978, also had green roofs designed and installed onto all of its roofs. In 1998, a new green roof was being proposed for Clinic 2 by Stephan Brenneisen, who stepped in to help with the design. Rather than install a green roof consistent in design with the rest of green roofs present, Brenneisen proposed to design a bioroof that would create ideal conditions for diverse plant and animal species (Cantor 2008). The design involves an adjustment of the crosssection and substrates of varying depths, which allowed for a wider range of flora and fauna, unlike the other green roofs of Clinic 1 which have uniform substrate depths, drainage configurations, and plantings. These changes were meant to result in the attraction of invertebrates as well as birds. Instead of planting the roof, the roof was meant to “plant itself ” over time by the germination of the seeds that are disturbed within the substrates. As vegetation develops, the roofs will resemble a variety of habitats, like dry meadows. The variety of habitats will attract many different kinds of other vegetation and animals, increasing the biodiversity of the roof. (Cantor 2008) The roof is visited by many species of birds, including the black redstart, an endangered species in the area. Other bird species include – and are not limited to – rock doves, wagtails, and house sparrows, which usually prefer fields, rivers, and mountain landscapes to the cityscape (Chrisman et al. 2005).
Aerial of the Klinic 2 building 16
View of the green roof on the Klinic 2 building
Why I chose this case study: This project is a good example of how a green roof was transformed into a habitat for birds. Designers took into consideration the natural landscape and observed what resident birds preferred to reside in, thus effectively recreating a habitat for the various birds that have been seen frequenting the roof.
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Plantings on the roof 38
Insects using the roof provide a source of food for visiting birds
The roof also involves some human experience, allowing those staying in the hospital to look out their windows and onto the green roof perchance to see a bird or two. However, while the visitors and employees of the hospital can admire the roof, the rest of the public does not seem to have access to the roof nor a good view to observe it from. Taking human experience into consideration will be part of my proposed design, allowing the public to see the roof as well as various species of animals that decide to utilize it.
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John Deere Works Project Name:
John Deere Works
Location:
Mannheim, Germany
Date:
2003
Client:
John Deere
Designer:
Hartmut Bauer
Green Roof Consultants/Architects:
Ulrich Zens
Type:
Type:
Size:
450 sq. ft.
Soil Depth:
2 in.
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The John Deere Works located in Mannheim, Germany, produces a large quantity of wastewater. This wastewater originally was sent to a treatment plant, which cleaned and discharged the water for a significant fee. The company hired Hartmut Bauer to design a wetland treatment system on their roof to cut down on water management costs. Because wetlands require a large amount of land which the company did not have, given their location in central Mannheim, Bauer designed the wetland system to be installed on their 450 square foot flat roof. This allowed the company to treat their water on site (Chrisman et al. 2005).
case study and the restoration of the tidal marsh. While the John Deere roof was initially built to naturally clean the waste water produced from the building, this kind of design is a potential role model for tidal marsh and/or wetland habitat restoration in urban areas should it be considered. To compensate for how much area tidal marshes and wetlands need, a series of roofs can be developed to hold water should this kind of restoration be considered. 41
The wetland system does not have a conventional soil layer, which makes the green roof lighter and avoids structural changes to the original roof. Rather than soil, the wetland uses phytolytic plants which grow in the waste water. Every day, 10 cubic meters of wastewater is pumped onto the roof and treated by various micro-organisms such as algae, fungi, and bacteria. Irises, lilies, reeds, rushes, and sedges, growing hydroponically in 2 inches of water on the roof, also help to purify the water (Steinbeis 2010). The constructed wetland has proven to be a valuable asset to the building and the environment. Economically, the wetland system cost 60% less than sending the wastewater to a water treatment plant. The building spends less on air conditioning since the roof has a cooling effect, and the system itself is low maintenance. The treated water can also be reused, which the company began doing in 2012 for toilet flushing, watering gardens, and pre-treatment of industrial materials. The John Deere Works’ goal for 2015 is to be a wastewater free factory (Steinbeis 2010).
Filtration system on the green roofs 42
Why I chose this case study: Although this is not a green roof meant for habitat restoration, I chose this case study because of how innovative it is. Wetlands usually need a large amount of land, which this building did not have, but managed to create an efficient wetland system in the small amount of flat roof they had. Aerial of the John Deere Works building 18
Plantings on the John Deere Works green roof
Earlier in this chapter I discussed the Meadowlands
The plants on the roof absorb the chemicals from the water 19
Design Site Selection and Land Use Analysis: The site for this design is New Brunswick, New Jersey in Middlesex County because of its proximatey to the Raritan River. New Brunswick is 5.8 square miles and contains over 50,000 residents, commuters, corporate and business employees, college students, and hospital and healthcare workers and visitors (www.newbrunswick.com). Some of the better known places in New Brunswick include the Johnson & Johnson world headquarters, the Heldrich Hotel, the Robert Wood Johnson Hospital, and Rutgers, the State University of New Jersey (www.cityofnewbrunswick.com). GIS data gathered from the CRSSA database was analyzed to create a map showing land use. It shows that the majority of New Brunswick is urban. The urban areas include residential (low, medium, and high), commercial, industrial, transportation (major roadways, bridges, railroads), and other urban data (cemeteries, stormwater basins, built up land, recreational and athletic land). Recreational and athletic land is considered urban because of the high levels of management and maintenance. New Brunswick Land Use 2007 AGRICULTURE BARREN LAND FOREST URBAN WATER WETLANDS
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Roof Selection: A series of roofs were selected based on the following criteria that I created: 1. Newer buildings were ideal. Older buildings may not have the capacity to hold a green roof due to the weight. Roofs on newer buildings were ideal because of their structural integrity for a green roof design. 2. Roofs that had a limited presence of generators, electrical units, and other rooftop utilities. 3. Roofs with more open space allow for the decrease of design disturbance and maximization of habitat presence. 4. Roofs that could potentially accommodate a green roof but have these utilities present on the roof can still be considered: the design will allow for maintenance staff to access these utilities without disturbing the habitats. Land Cover
MANAGED WETLAND IN MAINTAINED LAWN GREENSPACE
ARTIFICIAL LAKES
MIXED DECIDUOUS/CONIFEROUS BRUSH/SHRUBLAND
CONIFEROUS BRUSH/SHRUBLAND
MIXED FOREST (>50% DECIDUOUS WITH >50% CROWN CLOSURE)
CONIFEROUS FOREST (>50% CROWN CLOSURE)
MIXED URBAN OR BUILT-UP LAND
CROPLAND AND PASTURELAND
NATURAL LAKES
DECIDUOUS BRUSH/SHRUBLAND
OLD FIELD (< 25% BRUSH COVERED)
DECIDUOUS FOREST (10-50% CROWN CLOSURE)
ORCHARDS/VINEYARDS/NURSERIES/HORTICULTURAL AREAS
DECIDUOUS FOREST (>50% CROWN CLOSURE)
OTHER AGRICULTURE
DECIDUOUS SCRUB/SHRUB WETLANDS
PHRAGMITES DOMINATE COASTAL WETLANDS
DECIDUOUS WOODED WETLANDS
SALINE MARSH (HIGH MARSH)
DISTURBED WETLANDS (MODIFIED)
STREAMS AND CANALS
HERBACEOUS WETLANDS
TIDAL RIVERS, INLAND BAYS, AND OTHER TIDAL WATERS
MANAGED WETLAND IN BUILT-UP MAINTAINED REC AREA
The natural areas were then analyzed. The term “natural area” is defined as any land cover that is not urban (i.e. agriculture, barren land, forest, water, and wetland). The above key shows the specific types within all the non-urban land cover. The GIS data used for this map does not include street trees or small outdoor areas between buildings. According to this map, the natural areas are sparse. Much of the natural land cover borders the Raritan River, especially in the south east corner of the city. There is a large residential development surrounded by roads that fragment the forested areas between 22
the houses. The lack of natural land cover spurred inspiration for this design. New Brunswick is primarily urban and will continue to grow. In order to preserve natural areas for bird populations, they should be replaced.
Some of the buildings chosen included the Wellness Plaza, the Rockoff Hall parking garage, and the Heldrich Hotel. The remainder of these roofs are corporate and apartment buildings. The intention of the design is to pull the natural landscape into New Brunswick using these green roofs as a corridor. After observing the land cover map showing the lack of natural spaces within the city of New Brunswick, it is my goal to provide habitat through these green roofs, increasing and enhancing the existing biodiversity in and around the site. The roofs will create individual green spaces as well as a wider network between the entire group of roofs. The section diagram shows all the green roofs in elevation. Because all of the roofs vary in height, the green roofs will expand biodiversity in the area not only horizontally, but vertically as well. The various heights would allow people to potentially view the green roofs from out their office or apartment windows.
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Shrubs
Plant Palette Selection: The plant palette is based on recommendations by the Cornell Lab of Ornithology and the Audubon Society for attracting songbirds. Both organizations offer a list of plant suggestions to encourage the presence of songbirds on their properties.
Cornus sericea Redosier dogwood
Ilex verticillata Winterberry holly
Vaccinium angustifolium Lowbush blueberry
Panicum virgatum Switch grass
Schizachyrium scoparium Little bluestem
Lonicera sempervirens Trumpet honeysuckle
Parthenocissus quinquefolia Virginia creeper
Myrica pensylvanica Northern bayberry
Rhus typhina Staghorn sumac
Viburnum lentago Nannyberry
Sorghastrum nutans Yellow Indian grass
Perrenials 24
Asclepias tuberosa Butterfly milkweed
Echinacea purpurea Purple coneflower
Ratibida pinnata Yellow coneflower
Plant Benefits: There are 5 general time periods during a bird’s annual schedule: spring migration, nesting and fledging, bulking (the accumulation of energy for fall migration), fall migration, and over-wintering. Each selected plant plays a unique role during these 5 time periods, whether it’s providing food, nesting material, or attracting insects. Plants that attract insects allow for pollination of present plants as well as a food source for birds. Providing cover is important for birds seeking shelter from weather or predators. Returning bird will need spaces to nest as well as material to make their nests. Having places to perch allows birds to observe their surroundings as well as rest their weary legs (Attracting Songbirds, 2014).
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Some plants offer more than one benefit to the design. For example, Cornus provides cover, nesting, and perching. However, it is most important during the nesting period, in which it is available. Another example is Sorghastrum, which attracts insects, provides cover, and nesting material, but is integral in the spring when it attracts insects for returning birds and their growing fledglings.
Typha latifolia Common cattail
Vines
Grasses
Rubus idaeus American red raspberry
Many of the recommendations were for large trees, but because they would grow to be too heavy for green roofs it was decided that only small shrubs, grasses, and perennial flowers would be used. The selected plants are native to this area and can grow successfully in New Jersey’s climate.
Rudbeckia hirta Black-eyed Susan
Providing a viable source of food that would be available all year round was a high concern for this design. These food types include fruit, seeds, and insects, all which are critical at different moments in a songbird’s schedule. The attracted insects are a good source of protein for spring-returning birds and growing hatchlings. Various fruits and berries help birds to bulk up before they take flight for their fall migration. Hardy seeds and winter persistent fruits offer an additional source of food for birds that do not travel in the fall (Kress, 2006). Plants were specifically chosen to allow for a source of food for birds throughout the year, especially in the winter months when food is scarce. Some of the plants produce high quality fruit that disappear quickly, like Cornus and Vaccinium. Other plants produce fruits that are not as high in quality, but will be available in the winter, such as Ilex and Myrica.
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Worm-Eating Warbler using a branch to perch on
25
Spring Mig.
Attracts Edible Insects
J
F
M
A
Nesting/Fledging
M
J
J
A
S
Spring Mig.
Fall Mig.
O
N
D
Flowering Plants
Nesting/Fledging
Fall Mig.
J
F
M
A
M
J
J
A
S
O
N
D
J
F
M
A
M
J
J
A
S
O
N
D
Asclepias tuberosa Echinacea purpurea Ratibida pinnata Rudbeckia hirta
Asclepias tuberosa Echinacea purpurea Lonicera sempervirens Ratibida pinnata Rudbeckia hirta Schizachyrium scoparium Sorghastrum nutans
Vines Lonicera sempervirens Parthenocissus quinquefolia
Cover Cornus sericea Myrica pensylvanica Panicum virgatum Parthenocissus quinquefolia Rubus idaeus Schizachyrium scoparium Sorghastrum nutans Typha latifolia Viburnum lentago
Grasses Panicum virgatum Schizachyrium scoparium Sorghastrum nutans Typha latifolia
Small Shrubs
Nesting
Cornus sericea Ilex verticillata Myrica pensylvanica Rhus typhina Rubus idaeus Vaccinium angustifolium Viburnum lentago
Cornus sericea Myrica pensylvanica Parthenocissus quinquefolia Viburnum lentago
Nesting Material Panicum virgatum Schizachyrium scoparium Sorghastrum nutans Typha latifolia
O.W.
Bulking
Bloom Time Fruiting Time Winter Persistent
Perching Cornus sericea Ilex verticillata Myrica pensylvanica Rhus typhina Rubus idaeus Viburnum lentago
J
F O.W.
26
M
A
M
J
J
A
S
O
N
D
Bulking
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Planting Plan: The conceptual planting plant shows plants installed in clusters with the taller shrubs at the center fading out to smaller shrubs and grasses. The open space surrounding the clusters will be perennial flowers and shorter grasses. Small spaces between plantings will be other material such as soil so that birds can take dust baths.
The planting design will be an undulating form created by clusters that mimic the groupings of plantings scattered throughout a grassland. This will cater to birds with varying environmental needs.
The clusters will be planted based on a bird territory analysis. A study by Schoener (1968) discusses the territories of various birds. Species like the Grey Catbird, Carolina Wren, American Robin, and Song Sparrow, which have been known to frequent urban areas, have small territories which would allow for closer interaction by other species of organisms. Conversely, the Black-Capped Chickadee and the Northern Flicker have wider territories, which means there is less opportunity for interaction from neighboring species.
of bird species to utilize. Since the habitat roofs will be seenas a whole system and not as individual roofs, the design can cater to birds that require a larger area within their territory. Having an abundance of resources outside of nesting areas may also increase tolerance of bird species within another species' territory.
Spacing out the clusters of plantings are varying distances from other clusters allows for a wide range
Other material
Perennials
Shrubs
Mimus polyglottos Mocking bird
Thryothorus ludovicianus Carolina wren
Dumetella carolinensis Grey catbird
Poecile atricapillus Black-capped chickadee
Turdus migratorius American robin
Melospiza melodia Song sparrow
Grasses
13 acres
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Colaptes auratus Northern ďŹ&#x201A;icker
4 acres
1 acre
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Soil Cell Design: The green roof design will include a waterproofing membrane, protection layer, root barrier, insulation, drainage panel, and filter fabric, all which are typical in a green roof structure. Soil cell modules will provide various depths to allow varied depths of root systems. Plants with shallow roots, like perennials, will be planted into modules that can support 4 inches to 6 inches of soil, and plants with deeper roots, like the larger shrubs, will be planted into modules that can support 24 inches to 36 inches of soil. There will be
mid-range module that supports 18 inches of soil. The cells would aid in water containment and irrigation. Excess water will drain into the deeper parts of the cells, allowing plants to have access to water. The cells can also be used to collect water to create small pockets of wetland-like areas where wet-site tolerant species can be planted. The cells will also serve as a water source for the organisms utilizing the roof.
Modules 24" - 36" Cornus sericea Ilex verticillata Myrica pensylvanica Rhus typhina Rubus idaeus Vaccinium angustifolium Viburnum lentago
24" - 36"
Modules 18"
Modules 4" - 6"
Panicum virgatum Schizachyrium scoparium Sorghastrum nutans Typha latifolia
Asclepias tuberosa Echinacea purpurea Lonicera sempervirens Parthenocissus quinquefolia Ratibida pinnata Rudbeckia hirta
18"
4" - 6"
Soil cells Filter fabric Waterproofing Membrane Bonding Adhesive Insulation Insulation Adhesive Existing Roof
2.9’ 2”
3”
1” 3”
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Lathe House: A lathe house, a structure typically used for storing or growing plants, can be used by both plants and birds. I’ve created a simple design for a lathe house that will support the proposed vine plants, Trumpet honeysuckle and Virginia creeper. This produces another source of cover and perching for birds. Roofs that receive the most shade throughout the day - shorter roofs in the shadows of taller buildings - will not have the lathe houses because both Virginia creeper and Trumpet honeysuckle require large amounts of sun to grow. This will help keep heterogeneity among the roofs. Each lathe house will only have one of the species of vines growing on it so there is no competition between the plants.
Observation Roof: At the center of the chosen roofs is the Heldrich Hotel, which I have selected as the “observation roof ”. The Heldrich has the tallest roof, which makes it perfect for a 360-view of the rest of the roofs. With the aid of viewing binoculars, visitors can zoom in on the habitat roofs surrounding them for a closer look at visiting birds.
I chose to have only one roof for human access because it minimizes human interference with the habitats and the organisms that utilize those habitats. Compaction can be avoided, and nesting birds won’t need to flee from human presence. By allowing the habitats to grow and change on their own with minimal human interaction, I can reinforce the natural aspects of my design.
Observation Roof
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On both sides of the observation roof are small gardens designed with plantings similar to those on the habitat roofs. This gives visitors a chance to meander around the plantings and get an idea of how the habitats looks on a smaller scale. These intimate spaces will include viewing binoculars that allow visitors to view the roofs surrounding them from all angles.
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Simple concrete pavers will be used for the path that visitors will use to tour the small habitat spaces. These pavers will also be present on the habitat roofs but will only be utilized by the people maintaining the habitats.
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Closing Remarks I would like to leave you with this quote said by Dr. David W. Ehrnfeld, who is a professor of biology here at Rutgers University. He said, â&#x20AC;&#x153;We are now in the early phases of one of the worst extinctions of plants and animals that has ever occurred, and it is well documented that this is the result of human activityâ&#x20AC;? (Carney 1985). This does not have to be true. Just as much as we have a negative impact on the natural world, we can also have a positive one. Part of the definition of landscape architecture is this idea of ecological stewardship. We have a responsibility to uphold, as landscape architects, not only create beautiful spaces for people, but to respect and enhance the flora and fauna that resides in our environment. This design is one way to address ecological stewardship, specifically in our cities. We are becoming increasingly urban, but we continue to depend on nature for our survival. If we continue to reduce natural habitats for our own benefits, we may find ourselves in a predicament we may not be able to recover from. For the habitat we destroy, we should be replacing it. This will ideally keep the balance between the urbanizing world and the natural world. Biodiversity is a driving force in many ecosystem services we need to survive, so we need to treat nature as necessary, not expendable.
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Author's Thanks I would like to thank the following people, for which my success would not be possible withoutâ&#x20AC;Ś My board, Richard Alomar, Steven Handel, Myla Aronson, and Jean Marie Hartman, for helping me discover, research, write, edit, design, and finish my thesis My studio professor, Jean Marie Hartman, for constantly pushing me forward My classmates for their inspiration, great comments, and amazing attitudes My parents and family for their support and keeping me well fed My friends for listening to me talk nonstop about my thesis for the last year and not once getting mad about it â&#x20AC;ŚThank you.
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35. https://www.google.com/maps/ 36. http://www.greenroofs.com/projects/pview.php?id=148 37. http://www.greenroofs.com/projects/pview.php?id=148 38. http://www.greenroofs.com/projects/pview.php?id=148 39. https://www.google.com/maps/ 40. Cantor, Steven L. Green Roofs in Sustainable Landscape Design. New York: W.W. Norton &, 2008. 41. Cantor, Steven L. Green Roofs in Sustainable Landscape Design. New York: W.W. Norton &, 2008. 42. http://www.steinbeis.de/en/publications/transfermagazine/transfer-022010/pflanzenklaeranlage-mit-koepfchen. html 43. http://gallery.photo.net/photo/16714413-md.jpg 44. http://www.lafebervet.com/wp-content/ uploads/2012/07/Baby-birds-nest-AnnCam-width-400.jpg 45. http://www.outdoorphotogear.com/blog/wp-content/ uploads/2010/04/Worm_eating_Warbler_B9H22515.jpg Plant Palette Butterfly milkweed http://www.wildflower.org/gallery/result. php?id_image=20737 Purple cone flower http://www.wildflower.org/gallery/result. php?id_image=11707 Yellow cone flower http://www.wildflower.org/gallery/result. php?id_image=24155 Black eyed susan http://www.wildflower.org/gallery/result. php?id_image=11137 Virginia creeper http://www.wildflower.org/gallery/result. php?id_image=23582 Trumpet honeysuckle http://www.wildflower.org/gallery/ result.php?id_image=15050 Little blue stem http://www.wildflower.org/gallery/result. php?id_image=18686 Switch grass http://www.wildflower.org/gallery/result.php?id_ image=23557 Indian grass http://www.wildflower.org/gallery/result.php?id_ image=28755 Common cat tail http://www.wildflower.org/gallery/result. php?id_image=16132 Staghorn sumac http://www.wildflower.org/gallery/result. php?id_image=9947 Northern bayberry http://www.wildflower.org/gallery/result. php?id_image=32944 Redosier dogwood http://www.wildflower.org/gallery/result. php?id_image=22092 Nannyberry http://www.wildflower.org/gallery/result.php?id_ image=33087 Winterberry http://www.wildflower.org/gallery/result.php?id_ image=33501 American red raspberry http://www.delange.org/Raspberry/ DSC00066.jpg Lowbush blueberry http://images.fineartamerica.com/imagesmedium-large-5/2-ripe-maine-low-bush-wild-blueberries-keithwebber-jr.jpg 41