1. Prescribed fire as a tool for managing shrub encroachment in semi-arid savanna rangelands.
- Author
-
Lohmann, Dirk, Tietjen, Britta, Blaum, Niels, Joubert, David Francois, and Jeltsch, Florian
- Subjects
- *
PRESCRIBED burning , *SHRUBS , *ARID regions , *RANGELANDS , *SAVANNA ecology , *GRASSES , *PLANT species - Abstract
Abstract: Savanna rangelands worldwide are threatened by shrub encroachment, i.e. the increase of woody plant species at the cost of perennial grasses, causing a strong decline in the productivity of domestic livestock production. Although recent studies indicate that fire might be of great importance for semi-arid and arid savanna dynamics, it is largely not applied in the management of semi-arid rangelands especially with regard to woody plant control. We used the eco-hydrological savanna model EcoHyD to simulate the effects of different fire management strategies on semi-arid savanna vegetation and to assess their long-term suitability for semi-arid rangeland management. Simulation results show that prescribed fires, timed to kill tree seedlings prevented shrub encroachment for a broad range of livestock densities while the possible maximum long-term cattle densities on the simulated semi-arid rangeland in Namibia increased by more than 30%. However, when grazing intensity was too high, fire management failed in preventing shrub encroachment. Our findings indicate that with regard to fire management a clear distinction between mesic and more arid savannas is necessary: While the frequency of fires is of relevance for mesic savannas, we recommend a fire management focussing on the timing of fire for semi-arid and arid savannas. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF