Termite diversity in Neotropical dry forests of Colombia and the potential role of rainfall in structuring termite diversity

Abstract

Termites are ecosystem engineers that play an important role in the biotransformation of organic matter and re-distribution of nutrients in soil. Neotropical dry forests hold an important species endemism, but at same time, they are most threatened by climate change and intensifying land use. In Colombia, the best-protected dry forests are located in the Caribbean. The termite fauna of dry forests is poorly known. Their species richness and abundance in relation with diet and some environmental and soil properties were investigated. A total of 32 species in 1103 occurrences were found. Termitidae accounted for 78% of the species richness with Anoplotermes, Microcerotermes, and Nasutitermes being the dominant genera. Differences in species composition and abundance were found across sites. These differences may be linked to anthropogenic disturbance and species’ biology (such as having multiple nests and multiple queens), respectively. Strikingly, altitude positively correlated with species richness, thus reflecting an inversion of the common elevation-diversity gradient, which can be explained by increasing precipitation with altitude. Our results together with an analysis of the global termite species richness with rainfall implies that humidity positively effects termite diversity. In line, the studied Colombian tropical dry forests had low diversity compared to rainforests. A decline of species-rich soil feeding termites with decreasing humidity may explain why highest termite diversity occur in humid tropical rainforests.