Grassland Bird Response to Vegetation Structural Heterogeneity and Clearing of Invasive Bramble

Abstract

Spatial and temporal patterns of disturbance and the subsequent heterogeneity are critical in maintaining biodiversity within grassland ecosystems. Grassland birds have evolved within this ‘shifting mosaic’ to become reliant on specific habitat characteristics maintained under varying levels of both natural and anthropogenic disturbance. Unfortunately, grasslands in South Africa have been extensively transformed and remain poorly conserved, threatening grassland avifauna. Mistbelt grassland is a threatened vegetation type endemic to the province of KwaZulu-Natal, of which only 0.3% is formally protected. This study investigated seasonal and patch type heterogeneity in a Mistbelt grassland avian community by determining avian community structure and composition in four patch types, i.e. i) untransformed open grassland, ii) burnt grassland, iii) bramble-invaded and, iv) bramble-cleared grassland, during winter and summer. Avian assemblages were significantly different between the different patch types for e...