Diversity of Anurans in forests with different management histories in Gomba District Central Uganda

Abstract

Understanding the influence of management histories on biodiversity can inform sustainable management practices. However, few studies examine the response of anurans (toads and frogs) to management histories such as restoration, with most studies focusing on vegetation and iconic animal species like chimpanzees. This study assessed the diversity of anurans in Kaalo (degraded), Wabirago (restored) and Buddugadde (intact) forests in Gomba district, Central Uganda. To achieve the objectives, Visual Encounter Surveys in ten, 20 x 20 m plots per forest and Nocturnal Audible Call recordings were conducted. To compare anuran species diversity among forest types, generalized linear models were fitted with forest type as the explanatory variable. To compare species composition, the Bray–Curtis’s dissimilarity index was computed and visualized using non-metric multidimensional scaling ordination. To assess the influence of habitat characteristics on anuran diversity and composition, general linear models and Canonical Correspondence Analysis were used. The results showed that the restored forest had a significantly higher abundance than the degraded and intact forests. Species richness in the intact and restored forests was significantly higher than in the degraded forest, and there was no significant difference in species richness between the restored and intact forests. Evenness in the intact forest was significantly higher than in the degraded and restored forests. Shannon-Weiner diversity in the intact forest was significantly higher than in degraded and restored forests. Species composition was different between forest types, Ptychadena mascareniensis contributing the highest percentage dissimilarity. Species such as Afrixalus fulvovittatus, Amirana galamensis, Leptopelis christyi and Leptopelis kivuensis were recorded in the intact forest only. Abundance decreased with increasing stem density and increased with tree height. Species richness increased with tree height. Anuran composition was significantly influenced by both stem density and height. The results imply that forest management histories have variable effects on anuran diversity. Forest degradation may drive anuran species to extinction by reducing the number of species and altering the distribution of their relative abundance. Habitat characteristics determine anuran species abundance, richness and composition by probably influencing substrate temperature and habitat heterogeneity which are critical for the ecology of anurans.