Meeting Abstract
P3.68 Monday, Jan. 6 15:30 Thermal Sensitivity of Energy Assimilation among Plethodon from Different Elevations CLAY, T. A.*; GIFFORD, M. E.; University of Arkansas at Little Rock tclay1@gmail.com
Energy assimilation should be optimized for local environmental conditions and has the potential to limit species’ distributions. Within Plethodon there are numerous examples of elevational zonation between montane endemics and lowland congeners. Previous work suggests that montane endemics are physiologically restricted in distribution; whereas, interspecific competition primarily limits the distribution of the lowland species. In the laboratory, we determined the thermal sensitivity of energy assimilation for several montane and lowland Plethodon by measuring energy assimilation rates across a range of ecologically relevant temperatures. Preliminary data suggest that thermal sensitivity of energy assimilation differs between high and low elevation species, but is similar between species inhabiting similar elevation ranges. In particular, high elevation species appear to have narrower thermal performance curves than low elevation species, suggesting specialization to a narrower range of temperatures. In addition, high elevation species appear to optimize energy assimilation at cooler temperatures than do low elevation species. Preliminary data were collected from species that are phylogenetically closely related; species sharing similar habitats are sister species. We’ve expanded on this data set by including additional species from independent lineages and have analyzed the data from a phylogenetic perspective, allowing us to tease apart if phylogeny or similar adaptive responses characterize the observed patterns. In summary, preliminary physiological patterns support earlier predictions, that montane endemics are physiologically limited to colder, and perhaps more stable environments, and these cooler high elevation habitats should not preclude the low elevation species through compromised energetics.
