Altitudinal pattern of Odonata diversity in Kabylia (Algeria): a contrasting pattern in lotic and lentic habitats

Abstract

Environmental conditions change rapidly across altitude, shaping diversity and structure of communities. Because lotic and lentic communities are often distinct and experience different environmental and anthropogenic conditions, understanding whether the diversity of these communities changes similarly across altitude is fundamental to determine how biota responds to ecological gradients in a human-dominated landscape. In this study, we carried out a comparative analysis of the altitudinal pattern of the diversity of odonates in lotic and lentic ecosystems in Kabylia (north-central Algeria) across 16 sites (eight lotic and eight lentic sites). We estimated species richness, abundance, and Shannon index as well as three environmental factors (water temperature, pH, and human disturbance) in each site. We recorded a total of 33 species (10 Zygoptera and 23 Anisoptera) with 20 species in lotic sites and 28 species in lentic sites. We recorded a similar decreasing altitudinal pattern of water temperature and human influence, but no pattern in pH. Interestingly, species richness, abundance, and Shannon index increased with altitude in lotic sites, but showed a weak negative correlation in lentic sites. These contracting patterns could be due to the interplay of a geographic gradient in anthropogenic pressure and habitat-specific species sensitivity to anthropogenic stress.