Slow-moving sensitive species offer clues to the future through the past

Slow to go and picky about destination.  For dispersal limited species in tropical montane regions, projected climate change creates a huge challenge.  How can species that are highly sensitive to environmental conditions deal with a rapidly changing climate that may leave fragments of habitat unconnected by corridors?  Often the best way to predict how a species will react to future conditions is to study how they’ve reacted in the past.  G. Velo-Antón and colleagues have done just that in their new publication in Molecular Ecology, by focusing on a small, endemic, amphibian (Pseudoeurycea leprosa) that inhabits the tropical mountains of a biodiversity hotspot in central Mexico.  These salamanders, like many amphibians, are highly sensitive to climate conditions, and can act as indicators for how multiple species have responded in the past (and might respond in the future) to a quick shift in climate.  Through genetic sequencing and ecological niche modeling, the researchers were able to determine spatial connectivity and gene flow between several populations of the salamanders found in high elevation habitats.

Their results reveal much about past and present population connectivity.  The current distribution and genetic structure of the populations seems to be a result of spatial connectivity loss, the main mechanism that has resulted in isolated population fragments.  Since the last glacial maximum, the species shows a reduction in both range and spatial connectivity, indicating that climate conditions since then have been deleterious for the species.  This climate-induced isolation, in combination with recent anthropogenic changes throughout the landscape, point toward difficulties for species persistence as the climate continues to warm and tropical montane habitats continue to shrink and become disconnected.  The authors recommend that dispersal corridors be maintained for the species, and that active management such as habitat restoration and translocations might be necessary.  With such assistance, it may be possible to keep this and other climate sensitive species from getting stuck in the past.