Amphibian and reptile diversity in natural landscapes and human-modified habitats of the Sahara Desert of Algeria: A better understanding of biodiversity to improve conservation

Abstract

The spatial and seasonal variations in amphibian and reptile diversity were studied in different biotopes (lowlands, desert pavements “Reg,” Sabkhas “salt lakes,” date palm groves, wadis, and urban sites) at the Algerian Sahara Desert. No prior research has explored the connection between the distribution of reptiles and amphibians in Algeria’s Sahara and the environmental diversity of biotopes and landscapes. This study aimed to address this significant knowledge gap by investigating the relationships between Saharan habitats and landscapes and their impact on herpetofaunal presence, abundance, and diversity. The diversity of amphibians and reptiles was assessed based on quantitative data of species captures using nonparametric diversity indices, species richness accumulation curves, and similarity analysis. At the Region of Oued Righ (Northern Sahara Desert), we identified 3 amphibians, 19 lizards, and 10 ophidian species. These 32 species (approximately 30% of the Algerian herpetofauna) were classified into 2 orders (Anura and Squamata), 15 families, and 23 different genera. The study area included 8 protected species in Algeria and 9 endemic species to the Mediterranean region, including 1 amphibian and 7 species of reptiles. Acanthodactylus dumerilii was the most abundant species (20.5% of the total), whereas Chalcides ocellatus occurred in 32.9% of specimens. The highest values of species richness were recorded in palm groves with 22 species and Shannon’s diversity index (H’) was 3.5, whereas the lowest values were obtained in Sabkhas (5 species) and urban sites (7 species). The number of individuals experienced significant variations between study biotopes and seasons. Overall, species richness estimators (Chao2 and Jackknife1) revealed that the current survey achieved 90% of inventory completeness. Estimates and interpolations of species richness showed higher values in urban sites, palm groves, desert pavements, and wadis compared to Sabkhas and lowlands where completeness ranged between 90% and 100%. The analysis of similarity indicated low similarity values (<50%) between biotopes studied. The highest similarities were noted between the mesic biotopes (Sabkhas, wadis, and palm groves), the xeric and undisturbed biotopes (desert pavements and lowlands), whereas urban sites showed a distinct herpetofaunal community that was completely different of that recorded in Sabkhas, wadis, and lowlands.