INVASIVENESS AND BIOMASS PRODUCTION OF <em>LEUCAENA</em> <em>LEUCOCEPHALA</em> UNDER HARSH ECOLOGICAL CONDITIONS OF NORTH-CENTRAL NAMIBIA

Abstract

Very few agroforestry species perform well in the Cuvelai Basin of north-central Namibia due to the harsh climatic and edaphic conditions. Leucaena leucocephala is one of these species and has many ecological and economic benefits but it tends to be invasive. To evaluate the suitability of this species for agroforestry in Namibia, two experiments were conducted at the Ogongo Campus of the University of Namibia. As indication of invasiveness, seed germination and survival of seedlings under different management were monitored for 44 weeks and growth rates of 33-month-old sprouts were used to estimate the potential wood biomass production. Watering and tilling the land gave the highest number of surviving seedlings. Death of seedlings was highest during the dry cold and dry hot months. Height growth rate of sprouts was 1.98 m year^-1 and sun dried wood production was 15.8 tonnes ha^-1 year^-1. Low temperature, soil surface hard pan and extreme lack of moisture could limit seedling survival and hence invasiveness. Biomass production compares favourably with productivity of L. leucocephala grown elsewhere. The likelihood of the species becoming invasive is viewed as high only in cultivated, irrigated areas. Leucaena leucocephala could be utilised as an agroforestry species under proper management to minimise chances of it becoming invasive.