Diversity patterns of herpetofauna communities along a habitat alteration gradient in an Afrotropical large wetland – a test of the Intermediate Disturbance Hypothesis

Abstract Whilst wetlands are vital ecosystems supporting natural cycles and biodiversity, intensive agricultural practices and land use have led to widespread degradation, particularly in tropical Africa. In Uganda’s ‘cattle corridor’, an agro-pastoral landscape stretching across 84 000 km 2 , natural wetlands have been largely destroyed, and their degradation exacerbated by climate change. The Rufuuha wetland, located in southwestern Uganda, provides a study model to examine biodiversity across different habitat sectors: (i) intact, (ii) degraded, and (iii) restored areas. We studied the amphibian and reptile communities in Rufuuha wetland, which had been heavily degraded due to local community activities, such as agriculture and cattle grazing, before restoration efforts began in 2015. We found significant differences in species richness and diversity between the three areas. While species richness was similar across the areas, diversity and evenness were highest in the intact sector, followed by the restored and degraded areas. There was no support for the Intermediate Disturbance Hypothesis, whereas evenness clearly detected changes in the community structure of herpetofauna along the habitat gradient that species richness did not. Amphibians were well-represented in the survey, showing clear patterns related to habitat quality, while reptile sampling was less comprehensive. Our study demonstrates that restoration efforts can positively impact biodiversity in Afrotropical wetlands. However, it is not yet clear whether the same biodiversity levels as in the intact areas can be reached also in the restored areas. Further studies, particularly on reptiles, are needed to better understand the full ecological impacts of habitat restoration in this region.