INTRODUCTION: BIODIVERSITY PLANNING AND DESIGN

The state of biodiversity is of increasing concern around the world. Considerable agreement exists among scientists that habitat loss and degradation are among the leading causes of global biodiversity decline. Renowned entomologist and champion of biodiversity awareness E. O. Wilson (1988, 3) claims: "Overall we are locked into a race. We must hurry to acquire the knowledge on which a wise policy of conservation and development can be based for centuries to come."

If habitat loss is the leading cause of biodiversity decline, it follows that planning and design will be essential in any viable solution by directly conserving, protecting, or managing landscapes and habitats. Planners set policy and make plans to organize land use to meet multiple goals. Landscape architects create designs that are realized in physical form, affecting protection, change, and restoration of land and habitat. Landscape architects and planners engage biodiversity by working independently or in interdisciplinary teams that include conservation biologists, restoration ecologists, and natural and social scientists. Some of these teams have very successfully addressed biodiversity across a range of scales and geographical contexts.

As part of its case study series, the Landscape Architecture Foundation (LAF) sponsored this issue-based research into how landscape architects and planners have addressed biodiversity in their work. This case study undertook to learn how biodiversity fits with other goals in professional planning and design work; the role(s) of landscape architects and planners in interdisciplinary teams; and strategies for moving forward with biodiversity planning and design when faced with uncertainty and incomplete knowledge. The study includes five biodiversity planning and design projects, arranged into a comparative, issue-based case study representing a range of scales and geographic locations across the United States. The projects include the following:

• The Woodland Park Zoo's long-range plan, by Jones & Jones, Architects and Landscape Architects, in Seattle, Washington.

• A storm water management and wetland restoration project by Carol R. Johnson and Associates in Devens, Massachusetts.

• The Crosswinds Marsh Wetland Mitigation project, in Wayne County, Michigan, by the Smith Group/JJR of Ann Arbor, Michigan.

• The Willamette River Basin Study in Oregon, by University of Oregon landscape architect David Hulse and colleagues.

• The Florida Statewide Greenways System Planning Project, by the University of Florida Department of Landscape Architecture.

Our research found that biodiversity planning best succeeds when it is integrated with other goals, including environmental education, environmental impact mitigation, and regulatory compliance. Achieving multiple goals requires an interdisciplinary approach, and planners and designers often excel in leading such teams. Landscape architects and planners offer the ability to synthesize and visualize complex information, a familiarity with construction processes, skills in facilitating public participation, and expertise in implementing and managing projects. Additionally, the case study found that, although important, biodiversity is often a secondary or minor project goal in planning and design projects. It becomes more important in broad-scale, public policy-related projects and when mandated by regulatory and permitting agencies.

Data for planning and designing biodiversity projects are often incomplete for explicitly supporting planning and design decisions—an inherent problem related to the site- and species-specific nature of the data required. Despite the lack of good data, however, monitoring has rarely been conducted, due mostly to cost and convenience. This limits the ongoing involvement of landscape architects and planners in the projects they conceive, design, and build and thus to learn if the intended results were achieved. The lack of monitoring misses opportunities to (1) contribute new knowledge to science, (2) afford planners and designers the chance to expand their interdisciplinary collaboration with scientists and decision makers, and (3) "to learn by doing" to develop and refine planning strategies and design responses to address biodiversity more effectively.

Biodiversity is implicit in virtually all of the work of planners and landscape architects, and many signs point toward increased global interest and support for biodiversity planning. Both disciplines—planning and landscape architecture—include principles guiding the treatment of the natural environment in the ethical codes put forth by their professional societies. Landscape architects are expected to uphold values of environmental stewardship, especially as described in section ES1.13 in the American Society of Landscape Architects' (ASLA) Code of Environmental Ethics: "The principles of land use planning and design and the principles of wildlife habitat protection should be integrated to promote the enhancement, protection, and management of landscapes that promote wildlife" (American Society of Landscape Architects 2000, 1).

Similarly, the American Planning Association outlines its "Ethical Principles in Planning" to guide the behavior of both certified planners and all other working planners. Included in these principles is the statement that planners must "strive to protect the integrity of the natural environment" (American Planning Association 1992, 1). Biodiversity planning and design are central issues for the Society of Ecological Restoration International, which states the following as part of its mission: "to promote ecological restoration as a means of sustaining the diversity of life on Earth and reestablishing an ecologically healthy relationship between nature and culture" (Society for Ecological Restoration International 2004).

Biodiversity represents a significant growth opportunity for planning and design professionals. To become more active players, landscape architects and planners need to: become more familiar with the issues, terminology, and methods for biodiversity planning and design; understand the complex issue of representative species selection and how to apply a method in the context of species/habitat associations and ecological models; and to develop advanced skills for leading interdisciplinary teams. By examining how planners and designers have been involved in five specific projects in the United States and by identifying areas of strength and points of weakness, this study seeks to identify specific ways these professionals can participate in and contribute to biodiversity conservation. The study is intended to not only encourage design and planning professionals to take a more active role in projects that involve biodiversity issues but also to better inform them about biodiversity and conservation efforts in general.

DEFINITIONS OF BIODIVERSITY

Biodiversity has many definitions in the current literature written by independent researchers, government agencies, and international organizations. The differences among the definitions emphasize the complexity of the issue. Some include detailed spatial or temporal considerations, whereas others are quite simple. For example, the Keystone Center (1991, 2) describes biodiversity as "the variety of life and its processes," while biologist B. A. Wilcox (1982, 640) calls it "the variety of life forms, the ecological roles they perform, and the genetic diversity they contain." These simple definitions recognize that both the quantity of species and the ecological processes that affect those species are important. Conservation biologists R. F. Noss and A. Y. Cooperrider (1994, 5) extend the Keystone Center's definition to say: "Biodiversity is the variety of life and its processes. It includes the variety of living organisms, the genetic differences among them, the communities and ecosystems in which they occur, and the ecological and evolutionary processes that keep them functioning, yet ever changing and adapting."

Similarly, the U.S. National Biological Information Infrastructure (NBII), an organization composed of a wide array of federal, state, international, nongovernmental, academic, and industry partners, states that "biodiversity or biological diversity is the sum total of the variety of life and its interactions and can be subdivided into 1) genetic diversity, 2) species diversity, and 3) ecological or ecosystem diversity" (NBI I 2003). In 1992 the World Resources Institute, the World Conservation Union (otherwise known as the IUCN, or International Union for Conservation of Nature and Natural Resources), and the United Nations Environment Programme (UNEP) produced a joint publication, Global Biodiversity Strategy, in which biodiversity is defined as "the variability among living organisms from all sources, including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems" (WRI, 1992). Global Biodiversity Strategy further characterizes these three categories:

1. Genetic, or alpha, diversity is concerned with the variation of genes within species, including separate populations of the same species or genetic disparity within populations.

2. Species, or beta, diversity refers to the variety of species within a region, while species diversity can be measured in many ways; the number of species in an area, or species richness, is often used. Species diversity is also thought of in terms of taxonomic diversity, which considers the relationship of one species to another.

3. Ecosystem, or gamma, diversity refers to numbers of species in a particular location, the ecological functions of the species, the manner in which the composition of the species varies within a region, the associations of species in particular areas, and the processes within and between these ecosystems. Ecosystem diversity extends to the landscape and biome level.

One of the first scientists to address the issue of scale when measuring species richness was noted ecologist Robert Whittaker, who suggested thinking about species diversity in terms of alpha, beta, and gamma levels: alpha diversity referred to the species in a small, well-defined area, such as a study plot; beta diversity addressed the diversity of species between habitats, such as along a gradient; and gamma diversity was a tally of the number of species over landscapes or vast geographic areas (Whittaker 1975). Likewise, landscape ecologist Sheila Peck (1998) suggests that biodiversity can be characterized according to four different levels of biological organization: landscape, community, population, and genetic.

Some organizations and researchers include temporal and evolutionary aspects of biodiversity in their definitions. For instance, the broad definition put forth by The Nature Conservancy (TNC) and the Association for Biodiversity Information in their joint project Precious Heritage: The Status of Biodiversity in the United States not only includes references to genes, species, and ecosystems but expands to say that "biodiversity also encompasses the processes—both ecological and evolutionary—that allow life on Earth to continue adapting and evolving" (Groves et al. 2000, 7). This temporal component also surfaces in Peck's definition of biodiversity as "not only the range of variation that can be seen today, but that which is expressed over a period of time" (Peck 1998, 17).

The definitions above show three principal similarities: (1) biodiversity exists and needs to be understood at multiple scales, (2) biodiversity is inseparable from its physical environment, and (3) biodiversity is integral with ecological processes. For this study, we have integrated these similarities into the following working definition: Biodiversity is the totality, over time, of genes, species, and ecosystems in an ecosystem or region, including the ecosystem structure and function that supports and sustains life.

THE STATUS OF BIODIVERSITY—MEASUREMENT AND TRENDS

Whether or not such issues as spatial or temporal contexts or accompanying ecological processes are addressed, a general consensus exists that, at the very least, the concept of biodiversity rests on baseline knowledge of the number of species that exist on earth. This itself is a controversial topic; estimates of the number of species span orders of magnitude, ranging widely according to the method of calculation and the data used. E. O. Wilson (1988) suggests that the true number of species ranges anywhere from 5 to 30 million. In 1982, Terry L. Erwin's (1982) method of gassing and collecting insects from select trees in a Panamanian rain forest lead him to propose that, worldwide, there are 30 million species of tropical arthropods alone. Basing his estimates on the assumption that an inverse relationship exists between the numbers of species and body size, University of Oxford zoologist Robert M. May (1988) estimated global species richness to be between 10 and 50 million species. In 1995, the United Nations Environment Programme (UNEP) estimated that there are 13.6 million species on earth (Hammond 1995). This figure—which is very close to that of 13.4 million species proposed by Nigel Stork (1999) for the "Living Planet in Crisis" conference sponsored by the American Museum of Natural History in 1995—is currently considered an acceptable working estimate.

Ironically, biologists have the least information about the groups that are most common, such as insects. Currently, most "named" species are vertebrate and plant species, while the number of insect species is yet unknown. The best estimate of the total number of insect species on earth is 8.75 million, while only about 1.025 million (12 percent) have been named (see Table 1.1). In contrast, 4,650, or 97 percent, of the estimated 4,800 total number of mammal species have been named (Gibbs 2001).

In response to such uncertainties, efforts to catalog species diversity are ongoing at global, national, and regional scales. On a global scale, the World Conservation Union has an initiative to evaluate the status of more than one hundred thousand species in a five year period (World Conservation Union–IUCN 2000). This organization has been working for forty years to assess the global conservation status of species in order to draw attention to taxa threatened with extinction. One product of this assessment is the Red Book program, formed to reduce global extinction rates by making an index of biodiversity loss worldwide and by identifying species at the highest risk (World Conservation Union–IUCN 2001). By comparing the results from the year 2000 Red List of Endangered Species with those from the 1996 Red List, the World Conservation Union found that the severity of the extinction crisis was actually worse than had been previously estimated and that the populations of many species were declining rapidly (World Conservation Union–IUCN 2000). In total, the World Conservation Union considers approximately eleven thousand species of plants and animals to be threatened. Specifically, their results show that 24 percent of mammal species, 12 percent of birds, 20 percent of amphibians, 25 percent of reptiles, and 30 percent of fish face a high risk of becoming extinct in the near future (Table 1.2) (World Conservation Union–IUCN 2000, 1–2). Other global efforts include the Global Biodiversity Information Facility (GBIF) and Species 2000, two initiatives joined to build a comprehensive Internet database of species (Species 2000, 2002).

Clearly, we do not know the total number of all species on earth, and by the best estimates we have named only a small fraction of the existing biodiversity. At a global level, most expert accounts indicate that we are facing significant decline of species in some of the most species-rich segments of the world. Compounding this problem is the fact that most of the biodiversity in the world exists in the tropics, in developing countries with expanding populations and scant resources that are unable to deal with cataloging and conserving species. Undoubtedly, future global policy and planning measures must address this challenge through continued research, conservation, and development of sustainable, economical conservation policies.