25 April, 2019

Scorpions as environmental indicators

Andre Lira and co-workers have recently publised a study looking into how scorpion diversity, species richness, and species composition respond to bioclimatic changes (like forests with different gradients of humidity).

The study indicated that much of the scorpion composition and diversity in the study area were explained by a longitudinal bioclimatic gradient (wet-dry forest) and that species richness increased with increasingly dry conditions along the longitudinal gradient. Based on the results presented in this study, the authors belive that scorpions can be used as environmental indicators due to the high detectability, sensitivity to environmental attributes, and well known and stable taxonomy.

Understanding large-scale patterns of biological diversity is one of the most important issues in ecology. Parameters of scorpion assemblages may serve as a proxy to understand how arthropods respond to bioclimatic changes by adjusting their spatially structured distribution. We analysed how scorpion species richness, abundance, and composition respond to climatic variations found along a longitudinal gradient between wet (Atlantic Forest) and dry (Caatinga hypo and hyperxerophilic) forests in Brazil. A total of 20 sites were sampled four times along a 712 km longitudinal wet-dry bioclimatic gradient in north-eastern Brazil. We recorded 2653 scorpions from 12 species, belonging to five genera and two families. Environmental variables associated with precipitation and temperature had a strong effect on scorpion distribution, resulting in a distinct faunal composition at both extremes of the gradient. Species composition presented a turnover along the bioclimatic gradient, with beta diversity increasing towards the drier sites. The increase of dryness coincide with increases in temperature, moisture reduction, and a general environmental harshness. Our study, therefore, indicates that species sensitivity to climatic variation determines scorpion distribution in Neotropical forests.

Lira AFA, Salomão RP, Albuquerque CMR. Pattern of scorpion diversity across a bioclimatic dry-wet gradient in Neotropical forests. Acta Oecologica. 2019;96:10-7. [Subscription required for full text]

Thanks to Andre Lira for sending me their study!

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