Environmental Factors' Effect on Alpha and Beta Diversity of Butterflies in North‐East Algerian Forests

The specific factors determining butterfly alpha and beta diversity in Algerian forests remain insufficiently understood; not a single study has yet addressed this issue. Most previous studies in the region have exclusively focused on richness and abundance without evaluating how environmental variables shape community diversity. To address this knowledge gap, we conducted a field survey from May 2019 to March 2021 across three forest massifs in North‐east Algeria. Each forest comprised three distinct habitat types: a garrigue, Cork oak stands (COS) and Zean oak stands (ZOS). Canopy cover, vegetation and microclimate were considered as the main drivers of alpha and beta diversity. We quantified two autoecological traits of butterflies: larval host specificity and habitat specialization. Butterflies were counted along fixed transects using a hand net. We recorded 4879 individuals, representing 61 species of butterflies belonging to six families. Out of these, 13% are North African endemic species. More than 22% are forest specialists and 26% are monophagous. Across the structural vegetation gradient from open garrigues to closed COS and ZOS, alpha diversity for total butterflies declined. In contrast, forest specialists and monophagous species generally thrived in ZOS. Beta diversity was higher in ZOS and COS, whereas butterfly communities in garrigues exhibited a more homogeneous composition. Alpha diversity was mainly shaped by microclimate, canopy cover, season, habitat type, as well as shrub and herb cover percentage. Conversely, beta diversity was primarily influenced by canopy cover, microclimate and vegetation. Finally, we identified 9 indicator species, suitable for long‐term ecosystem monitoring programs in Algerian forests.