The huge diversity of taxa, ecological adaptations and evolutionary trajectories in subterranean environments has recently gained attention. The faunistic assemblages of groundwater habitats are known to show a high degree of endemicity and phylogenetic distinctiveness. Yet, the spatial, historical and environmental factors driving the composition of subterranean aquatic communities are often poorly understood. To partially fill this knowledge gap, we sampled copepods within 12 karst caves across Peninsular Italy. The collected specimens were classified to the species level. The resulting presence-absence matrix was then analyzed to assess: (i) between-cave taxonomic beta diversity, also partitioning between turnover and nestedness-derived diversity; (ii) the relative weight of geographical distance and climatic differences in shaping observed beta diversity. Beta diversity was high for most cave pairs, with turnover being the major component. Geographical Distance-Decay Models partially explained both total beta diversity and turnover patterns. However, Generalized Dissimilarity Models including also climate surfaces as predictors showed higher explanatory power, with contribution of climate consistently overwhelming that of geographical distance. Our results further confirm the uniqueness of subterranean copepod assemblages and strengthen the link between regional climatic conditions and composition of cave biocenoses, suggesting further research is needed to evaluate potential shifts under ongoing climate change.
Close yet not so similar, distant yet not so different: regional climate contributes more than geographical distance in explaining diversity patterns of copepods’ assemblages in a set of Italian karst caves
Emma Galmarini;
2023-01-01
Abstract
The huge diversity of taxa, ecological adaptations and evolutionary trajectories in subterranean environments has recently gained attention. The faunistic assemblages of groundwater habitats are known to show a high degree of endemicity and phylogenetic distinctiveness. Yet, the spatial, historical and environmental factors driving the composition of subterranean aquatic communities are often poorly understood. To partially fill this knowledge gap, we sampled copepods within 12 karst caves across Peninsular Italy. The collected specimens were classified to the species level. The resulting presence-absence matrix was then analyzed to assess: (i) between-cave taxonomic beta diversity, also partitioning between turnover and nestedness-derived diversity; (ii) the relative weight of geographical distance and climatic differences in shaping observed beta diversity. Beta diversity was high for most cave pairs, with turnover being the major component. Geographical Distance-Decay Models partially explained both total beta diversity and turnover patterns. However, Generalized Dissimilarity Models including also climate surfaces as predictors showed higher explanatory power, with contribution of climate consistently overwhelming that of geographical distance. Our results further confirm the uniqueness of subterranean copepod assemblages and strengthen the link between regional climatic conditions and composition of cave biocenoses, suggesting further research is needed to evaluate potential shifts under ongoing climate change.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
