Prioritizing regions for the conservation of amphibians with special emphasis on the Red Hills salamander (Phaeognathus hubrichti).

摘要

Amphibians are the most threatened vertebrate group in the world, and are experiencing rapid species declines and numerous extinctions. The most effective way to stem these losses is through the establishment of protected areas. The limited amount of funding available to such efforts requires that conservation agencies and biologists must find a way to properly focus their efforts and resources. Yet, there is no clear-cut method to prioritize areas for biological reserves. In fact, the identification of biologically important regions is one of the most debated topics in the field of conservation biology. As this debate wages on and as species continue to decline at an unprecedented rate, conservation biologists have come to rely on increasingly sophisticated methods for the identification of these areas. In this dissertation I focus on recently developed techniques for prioritizing reserve selection from macro to micro-scales for amphibians in the southeastern United States. For chapters one and two I focus on broad scale issues for wide taxonomic groups. Chapter one focuses on testing whether using environmental niche models rather than extent of occurrence maps to create richness patterns is a valid approach. I found that environmental niche models could be useful for generating richness patterns for understudied regions or taxa if proper precautions are taken. Chapter two focuses on implementing evolutionary data into richness and endemism patterns using all members of the family Plethodontidae found in the southeastern United States. I found that using evolutionary data in conjunction with traditional biodiversity metrics provides a unique and valuable perspective.;Chapters three and four narrow the focus to a single taxon, the Red Hills salamander (Phaeognathus hubrichti). The Red Hills salamander is a federally threatened species whose conservation has been hampered by their secretive and fossorial nature. To circumvent this problem, I conduct a conservation genetics study in chapter three and combine the data with spatial and life history data in order to make habitat acquisition recommendations in chapter four. I found that there are five distinct and well supported populations of P. hubrichti. Additionally, each population has extremely low levels of gene flow and high levels of inbreeding. I recommend that 21 sites are acquired and that attempts are made to restore habitat in-between known populations.