The Effects of Habitat Alteration on Anuran Diversity and Assemblages on Mount Mulanje, Malawi

Abstract

Anthropogenic disturbance and increased environmental degradation often lead to losses in species diversity. As continuous forests become increasingly limited, it is important to determine conservation and biodiversity values of intact forests and surrounding landscapes. Currently, there is little data on how anuran communities react to the alarming growth of habitat degradation in tropical East Africa, nor on the value of remnant forests. This study evaluated the alpha, beta and gamma diversity of frogs in an altered landscape on Mount Mulanje, Malawi, East Africa, and assessed the impact of habitat degradation and diversity of a landscape matrix of various habitat types. Nine sites were sampled: three intact miombo forests, three eucalyptus plantations, and three secondary forests. Twenty-nine species were found throughout these landscapes. Intact miombo forests contained significantly more frog species than the other habitats. The degree of canopy cover and area size appeared to determine species diversity across all three landscapes. Although eucalyptus plantations were impoverished, naturally regenerating secondary forests can help relieve the effects of habitat alteration. Nevertheless, degraded habitats cannot substitute for continuous blocks of forest; therefore understanding these differences is crucial for maintaining the biodiversity value in the long term.