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 and re‐distribution of nutrients in soil. The dry forests are endemic repositories, but at same time, they are most threatened by extensive livestock and crop farming, fires, and climate change. In Colombia, the best‐protected dry forests are located in the north. The termite fauna of dry forests are poorly known. The aim was to identify the termite species occurring in tropical dry forests of the Colombian Caribbean coast in relation to diet and precipitation, temperature, elevation, and soil properties. A total of 32 species in 1,103 occurrences were found. Termitidae accounted for 78% of the species richness with the Anoplotermes‐group, 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 polygyny and polydomy. Strikingly, our highest elevation site (334 m) had the highest species richness much higher than the two lower elevation sites. This implies an inversion of the common elevation‐diversity gradient, also found for termites which can be explained by increasing precipitation with elevation in the dry forest. An analysis of termite species richness at the global scale confirms that termite species richness correlates positively with rainfall. Hence, rainfall seems to positively affect termite diversity. In line, the studied Colombian tropical dry forests had low diversity compared to rain forests. A decline of species‐rich soil‐feeding termites with increasing aridity may explain why the highest termite diversity occurs in humid tropical rain forests. Abstract in Spanish is available with online material.

Phylogenetic Community Structure and Niche Differentiation in Termites of the Tropical Dry Forests of Colombia

“…In a former study, we characterized the termite communities of these three sites by determining species diversity and abundances and associating them with environmental variables [26]. We studied fives transect belts per site (hereafter called study plots) using the standardized belt transect sampling protocols of Jones and Eggleton [43] and Hausberger and Korb [44] developed for termites.…”

“…To determine the feeding type and characterize the food niche using δ 13 C and δ 15 N isotope analyses, we used specimens and material from a former study [26]. δ 13 C and δ 15 N isotope analyses were done for termite workers, but also for soil and leaf litter (leaf and small pieces of wood), which is potential food for the termites.…”

“…The species pool of the three study sites comprises 32 species that have been morphologically and genetically identified (Table A1: GenBank accession numbers MH09082–MH090914 and KU510330, KX267100, KX267099, KX267098, KX267095, KX267092) [26]. As the input tree for the phylogenetic community structure analyses, we used the combined COII, 12S, and 16S nucleotide sequences and performed a Bayesian approach using MrBayes 3.2.1.…”

“…As the main macro-detritivores, they essentially contribute to the biotransformation of wood and litter into organic matter and the re-distribution of structural soil components [24]. Tropical forests produce plenty of dead plant material, which termites consume [25,26]. Four functional feeding groups are distinguished in termites [27,28]: dead wood-feeders (group I); dead wood, leaf, plant-litter feeders (group II); humus feeders (group III); and true soil feeders (group IV).…”

“…No fungus-growing termites occur in the Neotropics, hence the differentiation of the feeding group IIF (i.e., fungus-feeder) is irrelevant [29]. Most termites of dry forests feed on twigs and litter and belong to feeding group I and II, while soil-feeders (sensu Anoplotermes -group) are relatively scarce in richness and abundance [26]. Nitrogen and carbon stable isotope ratios have been used in termites to elucidate feeding habits in more detail, including dietary preferences [30,31] and niche food differentiation [32,33,34,35].…”