chapter  9
49 Pages

The Role of Plantation Forests in Fostering Ecological Restoration: Experiences from East Africa

ByMulugeta Lemenih, Frans Bongers

Eastern Africa harbours 3 of the 34 global biodiversity hotspots: the Eastern Afromontane, the Horn of Africa and the Coastal Forests of Eastern Africa hotspots. Most importantly, east Africa is a world-renowned region for its high concentrations of diverse wildlife resources. Unfortunately, the biological richness of the region is degrading at an alarming rate (Nair, 2006). This highlights the urgency for large-scale conservation efforts to avert irreversible degradation. The challenge, however, is how these rich bio-resources of national, regional and international heritage can best be conserved. The fact that the biodiversity resources are largely degraded implies that restoration is needed; conservation alone is not enough. Degradation does not only imply the disappearing vegetation but also the deterioration of biophysical conditions of a site that may become barriers for self-recovery. The abiotic and biotic ecological conditions that characterize degraded lands include:

• low stock and quality of seeds and other propagules of native species in the soil seedbank;

• primacy of seeds of aggressive (competitive) grasses in the soil seedbank; • low numbers of animal-dispersed seed as a result of both low visitation by

disperser animal community and increased isolation of degraded sites from remnant forest patches;

• high incidence of herbivory; and • unfavourable ecological conditions such as poor soil quality, high desiccation

and strong direct irradiance (Ashton et al, 2001; Lamb et al, 2005; Cummings et al, 2005; Lemenih and Teketay, 2005; McNamara et al, 2006; Wassie et al, 2009a and b).