Predicting climate effects on aquatic true bugs in a tropical biodiversity hotspot

Abstract

Climate change is a matter of worldwide concern with severe predicted impacts on biodiversity. Here, we analysed the potential impacts of current and future climates on aquatic true bugs (Heteroptera) in relation to their distribution patterns and ecological preferences (based on a database generated from existing literature references and field collections). We considered the traits as ‘species thermal range’ and ‘emergence period’ to evaluate the future climate change impacts on the distributions of aquatic true bugs in the riverine regions of a tropical biodiversity hotspot, the Western Ghats of India. We used Species Distribution Models (SDMs) to evaluate the potential impacts of climate change on the distributions of aquatic true bugs. We modelled the distributions of twenty-six species of aquatic true bugs using different modelling tools through a carefully examined set of occurrence records to generate potential present distributions and to project these distributions into future scenarios of climate change. We observed increasing/decreasing range sizes of the species in the current and future scenarios. We found losses and increases of species' ranges in some regions, but not much variation in species richness. Similarly, no significant effect was observed in the distribution ranges for species with different duration of emergence period and thermal range in current and future climatic scenarios. Losses and gains in species richness would be concentrated in the mountainous area of the Western Ghats, whereas loss of species and the bigger difference between current and future richness will occur in the adjacent lowlands and towards central regions, including the network of protected areas of the Western Ghats. These areas are critical to buffer regional species loss in the future.Implications for insect conservationGiven the importance of aquatic true bugs as bioindicators and biological control agents, monitoring their range shifts should be routinely addressed in the conservation contexts of the Western Ghats.