The efforts of tiny forest termites have a big effect on the harmful ecological effects of drought in tropical rainforests, according to a new study, which reveals their important role in maintaining ecosystem function during periods of extended aridity. The results underscore the importance of conserving natural ecosystems by showing how a single insect community can help safeguard an entire forest during rapid environmental change. Termites are known to be some of the most important ecosystem engineers. They change soil properties by decomposing organic matter, wood and leaf litter on the forest floor, mixing and maintaining soil nutrients, and regulating moisture - all of which are key factors in maintaining rainforest ecosystems. Extended periods of drought pose a threat to these important ecosystem functions, which can greatly impact tree mortality. However, the overall ecological contributions of forest termites remain largely unquantified, and according to the authors, little is known about how drought-mediated changes to their communities affect tropical rainforest ecosystems during periods of environmental stress. By suppressing termite activity in sections of old-growth tropical rainforest in Malaysia during and after the 2015-2016 "super El Niño" drought, Louise Ashton and colleagues were able to assess the insect's specific role in rainforest ecosystem functioning. Ashton et al. discovered that termite activity and abundance more than doubled in plots where termite communities were present during drought compared to post-drought conditions, which resulted in higher litter decomposition rates, soil nutrient mixing and soil moisture. Furthermore, seedling survivability decreased in areas where termites were suppressed, according to the authors. The study's results suggest that increased termite activity during drought helps buffer important soil processes crucial for tropical forest survival and that human-mediated impacts on forest termite communities could make tropical forests less resistant to future drought.
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Journal
Science