HERPETOFAUNA ALONG AN ELEVATIONAL GRADIENT IN THE SIERRA MADRE ORIENTAL, QUERETARO, MEXICO

The spatial patterns of herpetofaunal diversity through elevational gradients have been little studied and therefore many aspects of their composition, arrangement, and functioning are unknown, especially in the mountainous areas of central Mexico. The Sierra Madre Oriental of Queretaro shows high environmental diversity in a small area with a range of vegetation, climate, and topography. This is reflected in the high vertebrate diversity, especially among amphibians and reptiles. We described and compared the diversity of amphibians and reptiles along an elevational gradient ranging from 1,028-3,100 m above sea level. Within seven segments along this gradient, we carried out systematic searches in microhabitats suitable for amphibians and reptiles. We conducted visual searches for a total of 680 person-hours during the rainy season of 2014 (July and August) and the dry season of 2015 (January, February, and March). We identified nine amphibian and 20 reptile species. Of these species, 41.1% are listed under some category of protection under Mexican law and 65.5% are endemic to Mexico. The communities above and below 1,900 m differed in their species composition with more species recorded at higher elevations; this change was associated with climatic and vegetation turnover. We found a significant nonlinear relationship between species richness and elevation with differences in community structure by elevation. Due to the high percentage of protected and endemic species and the dramatic turnover in community structure identified, we agree with proposals recommending the integration of the study area into a system of protected mountainous areas.

Automated summary

The study examines the herpetofaunal diversity along elevational gradients in the Sierra Madre Oriental of Queretaro, central Mexico. It found high environmental diversity in the area, with a range of vegetation, climate, and topography, leading to high vertebrate diversity, especially among amphibians and reptiles. The research identified a significant nonlinear relationship between species richness and elevation, with differences in community structure along the gradient.