Predicting annual stem diameter increment of selected tree species in Sinharaja rain forest by considering tree and stand level effects

Information on the diameter increment of tree species is important for developing a sustainable forest harvesting plan and reforestation. Fitting growth model can be utilized to get information. The objective this study was develop predictive annual multispecies stand in Sinharaja Rain Forest Sri Lanka. To fulfill objective, four linear mixedeffect models were fitted predict at breast height (dbh) trees by using dbh, natural logarithm as random effect. that contained coefficients intercept term, dbh log selected best-fitted based Akaike Criterion (AIC) value likelihood ratio test. Then, bestfitted expanded adding other subsequent variables describe effects competition from surrounding trees, size structure component, which maximum dbh. final comprised information log(dbh), stocking density, smaller than subject tree. Using model, 10 abundant calculated. It noted all have rates increase rapidly initial stage, then reach its unique rate. These patterns reflected different followed patterns. Therefore, consolidated into an effective empirical project future tropical rainforest.