Performance of some multipurpose tree species: the Forestry Commission experience.

Abstract

Rural afforestation in Zimbabwe has been heavily reliant on the genus Eucalyptus. Limited success has been achieved with these species in semi-arid areas. To broaden the species range and provide a wider product range, the Forestry Commission of Zimbabwe has been conducting on-station screening of African and Australian acacias. Of the African acacias, Faidherbia albida and Acacia tortilis exhibited high survival rates within the first year. Of the Australian acacias, Acacia auriculiformis succumbed to termite attacks except at Chesa and Acacia holosericea and Acacia colei appeared to be less susceptible to termite attack. Eucalyptus camaldulensis, Eucalyptus leptophleba and Eucalyptus tereticornis had better survival percentages than the acacia species tested. There are some indications that some acacia species, given more testing, can be selected for afforestation purposes in areas where eucalypts have been traditionally used. In Shurugwi, an evaluation of the performance of some multipurpose tree species planted out by farmers was carried out at eight years. The mortality of the tree species on-farm was variable, ranging from 39 to 64% in 1991 and 2 to 54% in 1996. Leucaena leucocephala, A. holosericea, Melia azedarach and Senna atomaria had the greatest growth and biomass production. Farmers preferred L. leucocephala and Casuarina cunninghamiana, which was correlated to their ability to produce useful poles. It is recommended that research that develops cost-effective strategies to improve survival levels of planted trees should be supported and alternative pole producing species should be made available to small holder farmers.


Transactions of the Zimbabwe Scientific Association Volume 72 (Supplement) 1998, pp. 10-14