Pinus patula Growth Areas and Yield Estimation

Of the three major species of pines grown commercially in South Africa, viz. Pinus taeda, P. elliottii and P. patula, the latter is in many respects the least tolerant of the three. For optimal growth, Pinus patula requires a MAP > 950 mm. Mean annual temperatures should ideally be > 13 degree Celsius but < 18 degree Celsius. P. patula is highly susceptible to Sphaeropsis sapinea after hail damage (Smith, 1998). It is, however, least prone to damage by snow because of the hanging nature of its needles. Pinus patula generally require a minimum soil depth of 0.7 m, but this can be relaxed to 0.6 m when clay content exceeds 35 percent.

Climatically optimum growth areas for Pinus elliottii have been defined in the ICFR`s Forestry Toolbox (Kunz, 2004), by mean annual precipitation (MAP) and mean annual temperature (MAT), as illustrated in This figure also shows the climatic conditions under which suboptimum growth would take place because conditions may at times be too cold and damage from snow occurs, or because occasional drought may occur. Optimum and sub-optimum growth areas of P. elliottii were mapped by applying these criteria to the one arc minute (1` x 1` of a degree latitude/longitude) databases of MAP (Lynch, 2004) and MAT (Schulze and Maharaj, 2004) for South Africa. Using Smith`s (1994) rule based approach and considering only his climatic criteria and not soil or management factors, Pinus elliottii yield estimates were done.