Projected Loss of a Salamander Diversity Hotspot as a Consequence of Projected Global Climate Change

Abstract

BackgroundSignificant shifts in climate are considered a threat to plants and animals with significant physiological limitations and limited dispersal abilities. The southern Appalachian Mountains are a global hotspot for plethodontid salamander diversity. Plethodontids are lungless ectotherms, so their ecology is strongly governed by temperature and precipitation. Many plethodontid species in southern Appalachia exist in high elevation habitats that may be at or near their thermal maxima, and may also have limited dispersal abilities across warmer valley bottoms.Methodology/Principal FindingsWe used a maximum-entropy approach (program Maxent) to model the suitable climatic habitat of 41 plethodontid salamander species inhabiting the Appalachian Highlands region (33 individual species and eight species included within two species complexes). We evaluated the relative change in suitable climatic habitat for these species in the Appalachian Highlands from the current climate to the years 2020, 2050, and 2080, using both the HADCM3 and the CGCM3 models, each under low and high CO2 scenarios, and using two-model thresholds levels (relative suitability thresholds for determining suitable/unsuitable range), for a total of 8 scenarios per species.Conclusion/SignificanceWhile models differed slightly, every scenario projected significant declines in suitable habitat within the Appalachian Highlands as early as 2020. Species with more southern ranges and with smaller ranges had larger projected habitat loss. Despite significant differences in projected precipitation changes to the region, projections did not differ significantly between global circulation models. CO2 emissions scenario and model threshold had small effects on projected habitat loss by 2020, but did not affect longer-term projections. Results of this study indicate that choice of model threshold and CO2 emissions scenario affect short-term projected shifts in climatic distributions of species; however, these factors and choice of global circulation model have relatively small affects on what is significant projected loss of habitat for many salamander species that currently occupy the Appalachian Highlands.

Geographic variation of resistance to water loss within two species of lungless salamanders: implications for activity

“…With the additional threat of rapidly changing climates, the importance of understanding the capacity to acclimatize is clear and urgent. Currently, plethodontids are predicted to experience significant v www.esajournals.org declines in suitable habitat by 2020 (Milanovich et al 2010). To make matters worse, recent research suggests that some species of lowland semi-aquatic plethodontids currently live at the edge of their thermal tolerances (Bernardo and Spotila 2006).…”

Predicted Changes in Climatic Niche and Climate Refugia of Conservation Priority Salamander Species in the Northeastern United States

“…Previous studies have evaluated potential effects of climate change on a subset of priority amphibian species (including salamanders) in the southeastern U.S. [31,32]; however, we are unaware of studies that have modeled the vulnerability of salamanders in the northeastern U.S. to climate change. Given the importance of salamanders to forest ecosystems [2,[4][5][6] and relatively high salamander richness and abundance in much of the northeastern region, our primary objective was to evaluate the vulnerability of conservation priority salamander species (23 total species) to climate change based on changes in the climatic niche.…”

Significance of pre-Quaternary climate change for montane species diversity: Insights from Asian salamanders (Salamandridae: Pachytriton)

“…On the other hand, East Asia was affected by global warming in the Pliocene (Zachos et al, 2001;Ravelo et al, 2004;Salzmann et al, 2011). This warm and wet period contrasts with the otherwise prevailing trend towards global cooling that existed since the late Miocene, and it could have devastated cold-adapted organisms in ways similar to current global warming (Pounds et al, 2006;Milanovich et al, 2010). Because these climatic shifts greatly altered precipitation patterns and environmental temperatures, we might expect to find signals in extant East Asian amphibians, whose life history and species richness are governed by precipitation and temperature (Buckley and Jetz, 2007).…”