Optimizing Stand Density in Teak Plantations

Abstract

An efficient way to increase productivity of teak plantations is to optimize their density for which an understanding of the stand dynamics, specifically, the effect of density on tree growth and form is needed. Using practical process models, it is found that the long-term optimal density index for teak plantations in Kerala, southern India, is 475. Analysis of data from the Inventory of Teak Plantations in Kerala-1997, consisting of 1170 sample plots representing teak plantations in Kerala, showed that only 4.8% of the stands have optimal density. Bringing up the density of understocked stands (index less than 400) and reducing the index of overstocked stands will increase productivity by 42%. It has been long suspected that the understory comprising tolerant species reduces growth of teak. This effect, however, was rarely documented and often disputed. In the developed model, the effect of understory density is described explicitly. It has been found that by controlling understory species in teak plantations, the mean annual increment in volume of teak can be increased by 30 percent. Removal of understory growth would also lead to social benefits by providing firewood to the local inhabitants other than its effects on the growth enhancement of teak trees. Although these results pertain to only one region in southern India, the developed methodology may be useful for Other places and Species.