Climatic and Altitudinal Criteria for Commercial Afforestation with Special Reference to Natal

Abstract

Criteria of altitude and climate such as mean annual precipitation, mean annual. January and July temperatures, mean daily maximum and minimum temperatures for January and July respectively and duration of soil moisture deficit are given for five main commercial tree species in Southern Africa. Using these criteria together with a basic agrohydrological data file compiled from irregularly spaced climate station information at intersections of a 10 km square grid, maps were prepared of optimum growing areas for the five species in Natal. The results are discussed for Acacia mearnsii, Eucalyptus grandis, Pinus elliottii var. elliottii, P. patula and P. taeda. The limitations and possible improvements to the maps and the extension of this technique to other areas are indicated. The maps will be of great advantage in planning future afforestation in Natal.