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 eld 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 signi cant 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.

Length–biomass equations to allow rapid assessment of semi‐aquatic bug biomass in tropical streams

“…There have been several studies investigating the impacts of habitat change in freshwater ecosystems on semi‐aquatic bugs (Ditrich et al, 2008; Dias‐Silva et al, 2020a, 2020b; da Silva Giehl et al, 2020), which have shown that they are vulnerable and sensitive to habitat alteration (Cunha et al, 2015, 2020; Vieira et al, 2015; Cunha & Juen, 2017, 2020; Guterres et al, 2020, 2021; Sundar et al, 2021). For example, studies have found lower beta‐diversity of semi‐aquatic bugs in altered habitats compared to forests, perhaps because water temperature was higher and water pH was more acidic in altered habitats (Dias‐Silva et al, 2020b).…”

Species Composition of Aquatic (Nepomorpha) and Semiaquatic (Gerromorpha) Heteroptera (Insecta: Hemiptera) in Kaeng Krachan National Park, Phetchaburi Province, Thailand

“…The richness and composition of aquatic insects in temperate regions fluctuates throughout the year, partially due to temperature changes among the seasons [61]. Similarly, the aquatic insect diversity in the tropical zones is strongly controlled by the seasons [61][62][63]. Richness and abundance of tropical aquatic insects are generally positively correlated with amount of rainfall [64,65]; however, an excessive amount of rainfall can significantly cause the decline of aquatic insects in streams [66].…”

Distribution model and prediction of the tree fern Alsophila costularis Baker (Cyatheaceae) in China

“…The similarity indices of 0 suggest a complete mismatch between actual observations and predictions of the species, while a value of 1 indicates that the predictions are perfectly matched to observations (Leroy et al., 2018 ). The similarity indices not <0.7 indicate an acceptable threshold (Sundar et al., 2021 ). We selected the maximum training sensitivity plus specificity threshold (MTSS) (Liu et al., 2005 ) as the threshold value of the binary presence/absence model.…”