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Abstract Detail

Conservation Biology

Philbrick, C. Thomas [1], Bove, Claudia P. [2], Stevens, Hannah [3].

Geographic Distribution of Neotropical Podostemaceae.

Podostemaceae, a primarily tropical family restricted to river-rapids and waterfalls, are widely reported to contain a high number of species with narrow geographic ranges (high endemism). Significant local endemism, combined with observations that large dams can result in habitat loss along hundreds of kms of a river, lead to concerns of potential species extinctions. Geographic distributions for neotropical species were assessed using field studies, herbarium holdings and Geographic Information Systems. Regional floristic comparisons indicate that some major hydrographic regions (Amazon and Paraná River Systems) or major areas (eastern Brazil) possess largely unique podostemad floras. Establishment of meaningful estimates of the geographic ranges of species that occur in specialized habitats (e.g., river rapids) is difficult. Two measures of geographic distribution are discussed. The number of rivers/river systems in which a species occurs can provide valuable insight for assessing extinction threat. Such an approach yields estimates of species documented from a single river (one-river endemism) ranging from 17-38%. A second measure (IUCN ‘extent of occurrence’) indicates that species distributions range from <50 km2 to >1 million km2. Examples of the extremes of this range occur in such genera as Castelnavia and Podostemum. The majority of species assessed, however, possess extent of occurrence estimates of <100,000 km2. Limitations of current taxonomy are discussed relative to establishment of meaningful estimates of species distributions in some genera (e.g., Apinagia). IUCN assessment categories are provisionally applied to neotropical Podostemaceae. Approximately one third of species fall into one of three categories: Data Deficient (DD), Least Concern (LC), and Vulnerable (VU). Ten species are critically endangered (CR).

Broader Impacts:

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1 - Western Connecticut State University, Biological & Environmental Sciences, 181 White Street, Danbury, CT, 06810, USA
2 - Museu Nacional, Universidade Federal do Rio de Janeiro, Departamento de Botânica, Quinta da Boa Vista, Rio de Janeiro, RJ, 20940, Brasil
3 - The New York Botanical Garden, 200 Southern Blvd, Bronx, NY, 10458, USA

Aquatic plants
river rapids
habitat loss
tropical river.

Presentation Type: Array
Session: 52
Location: 551A/Convention Center
Date: Wednesday, August 4th, 2010
Time: 11:00 AM
Number: 52004
Abstract ID:110

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