ISSN 1541-7115 Green Roofs and Biodiversity Volume 4, Number 1 • December 2006 1000 Washington Avenue, Brooklyn New York 11225 • 718.623.7200 http://www.urbanhabitats.org/ Editors Steven E. Clemants Vice President for Science, Brooklyn Botanic Garden, and Codirector, Center for Urban Restoration Ecology Janet Marinelli Guest Editor and Member of the Steering Committee, Center for Urban Restoration Ecology Gerry Moore Director of Science, Brooklyn Botanic Garden Elizabeth Peters Director of Publishing, Brooklyn Botanic Garden Managing Editor Niall Dunne Brooklyn Botanic Garden Copy Editor Joni Blackburn Brooklyn Botanic Garden Website Alison Dorfman Dave Allen Brooklyn Botanic Garden Publisher The Center for Urban Restoration Ecology A collaboration between Rutgers University and Brooklyn Botanic Garden ISSN 1541-7115 Green Roofs and Biodiversity Volume 4, Number 1 Page 1 Introduction Janet Marinelli, Guest Editor Page 3 Long-Term Vegetation Research on Two Extensive Green Roofs in Berlin Manfred Köhler University of Applied Sciences Neubrandenburg, Brodaer Str. 2, 17041 Neubrandenburg, Germany Page 27 Space for Urban Wildlife: Designing Green Roofs as Habitats in Switzerland Stephan Brenneisen University of Applied Sciences Wädenswil (HSW), Grüental, Postfach 335, CH 8820 Wädenswil, Switzerland Page 37 Ground-Nesting Birds on Green Roofs in Switzerland: Preliminary Observations Nathalie Baumann University of Applied Sciences Wädenswil, Dept. of Natural Resources Sciences Green Roof Competence Centre, Grüental, Postfach 335, 8820 Wädenswil, Switzerland Page 51 Extensive Green Roofs in London Gary Grant EcoSchemes Ltd, Unit 1, Coombe Lane, Axminster, EX13 5AS, U.K. Page 66 Rare Invertebrates Colonizing Green Roofs in London Gyongyver Kadas Royal Holloway University of London, Biological Sciences, 4 West Heath Drive, London NW11 7QH U.K. Page 87 Green Roofs and Facades: A Habitat Template Approach Jeremy T. Lundholm Saint Mary's University, Department of Biology/Environmental Studies Program, Halifax, Nova Scotia, B3H 3C3 Canada - i - ALSO IN THIS ISSUE... Page 102 The Floristic Composition and Community Structure of the Forest Park Woodland, Queens County, New York Carsten W. Glaeser City University of New York, Herbert H. Lehman College, Department of Biological Sciences, 250 Bedford Park Blvd., Bronx, NY 10468 Page 127 Short-Tailed Shrews (Blarina brevicauda) Exhibit Unusual Behavior in an Urban Environment Virgil Brack Jr. Indiana State University, Department of Ecology and Organismal Biology, Terre Haute, Indiana 47089 Page 133 Habitat Observations of Geum vernum in Kings Point Park, Long Island, and a Discussion of the Species' Potential Invasiveness in New York State Andrew M. Greller,¹ Virginia Dankel,² and David C. Locke³ ¹ Queens College, Biology Department, Queens College, CUNY, Flushing, New York 11367 ² c/o BOCES of Nassau County, 2850 North Jerusalem Road, Wantagh, New York 11554 ³ Queens College, Chemistry Department, Queens College, CUNY, Flushing, New York 11367 BOOK REVIEW Page 142 Skinny Streets and Green Neighborhoods: Design for Environment and Community, by Cynthia Girling and Ronald Kellett Carmela Canzonieri - ii - URBAN HABITATS, VOLUME 4, NUMBER 1 ISSN 1541-7115 Introduction: Green Roofs and Biodiversity http://www.urbanhabitats.org Introduction: Green Roofs and Biodiversity Until recently, the design of green roofs was especially sunny and shady areas, are created, based almost entirely on engineering initial plantings are enhanced, and a minimal considerations. Much has been written about amount of irrigation and maintenance is provided. how extensive green roofs—those that are grown Stephan Brenneisen discusses his work in on a shallow substrate and require little irrigation Basel, Switzerland, where green roofs have or other maintenance—affect building become an important part of the city's performance, especially energy consumption and biodiversity strategy. Based on research storm-water retention. Although advocates have conducted at a 90-year-old green roof in Zurich, said repeatedly that green roofs can be a source in which native soil was used and which has of habitat for wildlife, there have been few become an orchid meadow with high studies and little data to back up these claims. conservation value, the use of natural soil as well In the past few years, however, researchers as different substrate thicknesses is stipulated in have turned their attention to the role that green the design criteria for green roofs in Basel and roofs can play in the conservation of biodiversity other Swiss cities. On the most biodiverse of the in towns and cities, where natural habitats are Basel green roofs studied, a dense combination few and far between. They have produced a of microhabitats supports 79 beetle and 40 spider small but growing body of evidence suggesting species; 13 of the beetles and 7 of the spiders are that green roofs can indeed provide living space endangered species. for plants and animals, at least mobile species The work in Basel has been the inspiration such as invertebrates and birds. Six pioneering for the creation of innovative replacement papers on the biological value of extensive green rooftop habitat in London. The redevelopment of roofs are included here. derelict "brownfield" sites, which have become Some of the longest-term data come from critical habitat for many species since World Germany, where the first wave of green roof War II, has resulted in a squeeze on the city's construction came at the end of the 19th century. biodiversity, leading biologists to look to In his paper, Manfred Köhler describes his buildings as potential habitat. In his paper, Gary studies of green roofs constructed in Berlin in the Grant reviews the various types of green roofs mid-1980s, representing the second boom in that have been constructed in London during the German green roof creation. Köhler concludes past 15 years. Among the most interesting are that a relatively diverse flora is possible on the customized "brown roofs" constructed from extensive green roofs in inner cities as well as recycled crushed concrete and brick aggregate rural areas. He also suggests that plant diversity specifically for the black redstart, a rare and can be even higher if varied microclimates, protected bird threatened by the development of - 1 - URBAN HABITATS, VOLUME 4, NUMBER 1 ISSN 1541-7115 Introduction: Green Roofs and Biodiversity http://www.urbanhabitats.org their brownfield refuges. Gyongyver Kadas species adapted to shallow substrates and discusses the results of her surveys of extreme temperature and moisture conditions— invertebrate diversity on green roofs in London, the same characteristics of extensive green focusing on three groups: spiders, beetles, and roofs—and therefore can be useful natural aculeate Hymenoptera (wasps, bees, and ants). models. The natural rock barren ecosystems also She has found a higher abundance of typically include varied microtopography, invertebrates on rooftops than at brownfield sites, increasing the diversity of the vegetation and and at least 10% of the species from the target providing a greater range of habitats for groups are nationally rare. invertebrates. Nathalie Baumann presents preliminary data These papers point to other promising areas from a long-term study of green roofs as of research. For example, what role can green potential bird habitat in Switzerland. Her roofs play in regional landscape and ecological research suggests that green roofs may be able to planning? Can they function as green corridors, provide not only food habitat but also breeding linking fragmented habitats and facilitating habitat for ground-nesting birds such as the wildlife movement and dispersal? endangered little ringed plover and northern Although the data presented in these papers lapwing. are for the most part preliminary, they suggest As several of the papers in this issue show, that if suitable niches are provided on green green roof design is becoming more roofs, plants and animals will move in rapidly sophisticated. Ecologists have begun looking for and establish communities. Customized green alternatives to widely used sedum mats that roofs can even provide habitat for declining and incorporate microhabitats customized for endangered species, suggesting that they have particular species and/or more closely mimic the potential to be an essential tool in species natural habitats, with varied microtopography conservation. (including hollows and "clifflets"), scattered Urban habitats are often seen as too disturbed, rocks, rubble, dead wood, and more diverse too degraded, and too depauperate to serve as vegetation. In fact, there is an increasingly reservoirs of biodiversity. Even ecologists have nuanced understanding of creating entire plant been slow to acknowledge that cities offer communities on rooftops. In his paper, Jeremy biological benefits. Green roofs may prove them Lundholm suggests that green roof designers wrong. should look to natural analogs of these manmade environments, especially rock outcrop habitats Janet Marinelli such as cliffs, scree slopes, and limestone Guest Editor pavements. These rare habitats include suites of - 2 - URBAN HABITATS, VOLUME 4, NUMBER 1 ISSN 1541-7115 Long-Term Vegetation Research on http://www.urbanhabitats.org Two Extensive Green Roofs in Berlin Long-Term Vegetation Research on Two Extensive Green Roofs in Berlin by Manfred Köhler University of Applied Sciences Neubrandenburg, Brodaer Str. 2, 17041 Neubrandenburg, Germany