Reptiles and amphibians are among the most diverse vertebrate groups with more than 20,000 species. Forests are vital to maintaining species diversity and promoting species diversification. Forests are vital to maintaining species diversity and promoting species diversification. Forests are habitats for over half of all reptile species and the most common habitat for amphibians. Perhaps surprisingly, herpetofauna affect forest ecosystem processes like decomposition, disperse seeds, and even pollinate flowers. Some have even been labelled ‘ecosystem engineers’. Many factors explain distribution and diversity trends displayed by amphibians and reptiles found in forest habitats. Amongst these are elevation, latitude, biogeography, and features of the climate such as precipitation, relative humidity, and temperature. Interestingly, the evolutionary inertia of lineages found in a particular area are under similar selection pressures. Many of these selection pressures form the basis of parallel trends in evolutionary ecology and functional roles across a diverse array of both amphibian and reptile species around the world. Like most other groups, herpetofauna diversity is highest in the tropics and decreases towards higher latitudes. There are limited numbers of species of reptiles and amphibians in boreal forests due to short summers and long winters, with spring and summer conditions governing much of their activity, distribution, and behavior. In contrast, tropical forests host higher diversity and abundances of herpetofauna, particularly forests in Latin and South America, central Africa, and southeast Asia. While these latitudinal gradients are perhaps the most pervasive and recognizable biogeographic patterns, there are important exceptions. Anurans (frogs), caecilians (worm-like amphibians), squamates (snakes and lizards), and crocodilians are more diverse in tropical regions, however, salamanders and turtles are more species rich at higher latitudes. This is mainly due to the ancient geographic origins of these lineages and their inability to disperse long distances and/or cross biogeographic barriers. Though studies are limited, climatic (especially temperature for reptiles and humidity for amphibians) constraints might shape the distribution of herpetofauna species within biogeographic regions. Additionally, elevation contributes to physical and physiological barriers that limit species’ dispersal and distribution. Topographically complex regions seem to promote higher and faster rates of speciation. Mountains can be important refugia and key areas for biodiversity conservation. Climate variation across altitudinal gradients is especially important for ectothermic species like amphibians and reptiles, because they are critically dependent on water availability and temperature. Mountains within drier regions of Brazil, for example, promote orographic rainfall that supports forest inselbergs in a semiarid area. Historically, higher elevation areas were key to herpetofauna resilience during glacial cycles, acting as refugia for species that could move to more suitable climates as climatic conditions changed.
