Landscape heterogeneity can play an important role in providing refugia and sustaining biodiversity in disturbed landscapes. Large Macrotermes (Isoptera) termite mounds in miombo woodlands form nutrient rich islands that sustain a different suite of woody plant species relative to the woodland matrix. Miombo woodlands cover 2.7 million km2 of southern-central Africa, and contemporary land-use practices have seen a rapid decline in cover. Financial constraints within reserves have also had deleterious consequences, and aerial studies have shown a decrease in cover even within reserves as a consequence of stocking pressures. We investigated the role of termitaria in providing habitat for cavity-using birds in miombo woodlands that had been greatly impacted by elephants and fire, by comparing the availability of habitat favored by cavity-using birds (tall trees, trees with deadwood, and cavities) on and off mounds, and then testing its effect on species richness and abundance of cavity-using birds. We surveyed 48 termitaria paired with 48 woodland matrix sites in the breeding season; and 54 matrix-termitarium pairs in the non-breeding season in Chizarira National Park, Zimbabwe.
Results/Conclusions
Generalized linear mixed-effects models showed that termitaria harboured significantly higher densities (ha-1) of habitat components considered important for cavity-using birds. Density of trees > 6 m in height and incidence of trees with deadwood was nearly 10 times greater on mounds than in the matrix. A model selection procedure showed that termitaria provided refugia for cavity-using birds and contributed to the resilience of bird communities through high on-mound densities of trees with deadwood. Large termitaria thus appear to play an important role in maintaining functionally important components of the avifauna in heavily impacted Miombo woodlands.
( see “Grant S. Joseph et al. 2011. Large termitaria act as refugia for tall trees, deadwood and cavity-using birds in a miombo woodland. Landscape Ecology. 26 : 439-448” for a full description of the study)