Christopher P. Dunn

Restoring diversity: strategies for reintroduction of endangered plants.

The reintroduction of rare and endangered species to their natural habitats is becoming an increasingly important tool in ecosystem management. This book seeks to unify concepts in the field of restoration, and fill significant technical and policy gaps.

Keeping taxonomy based in morphology

financial rather than technological. In most countries, the scientific community simply is not prepared to allocate significant resources to taxonomic research of poorly known organism groups, not even from funds dedicated to biodiversity research [Statistics on Swedish biodiversity funding (http://www.artdata.slu.se/ Svenska_artprojektet_Eng.htm)]. A glowing exception is the USA, where new generations of taxonomists have been trained in the PEET program since 1995 [5] and where the recent US

Introduction: Long-term ecological sustainability of wetlands in urbanizing landscapes

14 million Planetary Biodiversity Inventories programme (http://www.nsf.gov/pubs/2002/ nsf02186/nsf02186.htm) aims to complete the world species inventory for some selected taxa. In countries with less supportive scientific communities, separately funded national inventories could be the key to significant acceleration of the biodiversity census. The so-called Swedish Taxonomy Initiative (STI) provides a nice example (http://www.artdata.slu.se/ Svenska_artprojektet_Eng.htm). It was launched in January 2002 and aims to complete an inventory of Sweden’s fauna and flora of multicellular organisms within 20 years. STI is likely to expand the current list of 50 000 Swedish species considerably, both with named and previously unnamedtaxa.Theprojectwill requiresomeEuro65 million in direct funds to taxonomic research, inventory work and outreach focused on the Swedish flora and fauna, and another Euro 65 million to support incorporation of the resulting material into existing natural-history collections, making it one of the largest biodiversity initiatives yet. The geographical constraint is not ideal from a scientific perspective but the forte of national inventories is that they can provide society with the necessary deliverables. In addition to taxonomic research, STI will produce illustrated identification keys and basic facts concerning the distribution and biology of all species in Swedish. This will broaden the knowledge base for the identification and monitoring of biodiversity, provide a rich information source for schools, and significantly boost public awareness of local biodiversity and its conservation. National inventories also have the potential of spreading to neighbouring countries. Indeed, other Nordic countries are now considering taxonomy initiatives of their own. The completion of the first national biodiversity map will undoubtedly be a significant event. Will the Swedes, inspired by their Linnaean tradition, be first?

La Selva: Ecology and Natural History of a Neotropical Rain Forest

The proportion of the world’s population classified as urban is now more than 50% (UN 1982), and urban development is recognized as a significant ecological trend (Vitousek, 1994). The changing percentages of natural habitats, including wetlands, near Philadelphia, Pennsylvania (USA) illustrate the impacts of urban growth (Detwyler, 1972). The percentage of wetlands remaining was inversely related to the spatial pattern of urbanization. In the contiguous lower 48 states of the United States, it is estimated that intensive urban uses accounted for 22% of saltwater wetland losses and 6% of freshwater wetland losses since settlement (OTA, 1984). In a more recent regional study, 18% of small (less than two ha) freshwater wetlands in the Portland, Oregon (USA) metropolitan area were destroyed as a result of urbanization over a ten-year period from 1982 to 1992 (Holland et al., 1995). And 25% of the remaining wetlands were seriously degraded by human activities. The conservation of urban wetland habitat is challenging because of the specific threats to which these systems are subjected and the desire to utilize those remaining sites for multiple and often incompatible purposes. Most remaining wetlands in urbanizing regions have been altered and degraded (Kusler et al., 1988). One consequence of urbanization is alteration of the hydrologic cycle, including stormwater runoff and drainage from the surrounding watershed (Watson et al., 1981). Changes in runoff affect peak flows, flow volumes, and changes in water quality (Johnson and Dean, 1987). Wetlands are intimately tied to the hydrogeomorphic setting (Brinson, 1993), which, if altered, can threaten the ecological sustainability of these systems (e.g., Hicks and Larson, 1997). At the same time, it has long been recognized that wetlands in urban settings are a valuable resource (Niering, 1968). Wetlands are important components of urban landscapes, providing flood storage and water quality functions, groundwater recharge and discharge, sediment retention, and habitat. Indeed, a major challenge we face today is to determine whether existing wetlands in urban landscapes can be used for multiple purposes while maintaining their integrity as ecosystems. Another area demanding attention is the assessment of wetland management and restoration options in the urban landscape. We need to address how urban residents and managers can develop and use an understanding of wetland ecology and dynamics as a means to improve the quality of the urban environment. The three papers in this special section attempt to address these issues: urban wetlands utilized for multiple purposes, habitat management and restoration, urban impacts on wetlands, and public involvement. Reinelt et al. describe the impacts of urbanization on wetland hydrology and consequences for ecological integrity. They summarize the types of impacts to wetlands caused by urbanization and provide recommendations for the effective management and conservation of wetlands in a rapidly urbanizing