Abstract:

In order to provide scientific and reasonable reference for low-quality and low-benefit forest in Hainan Province, the author studied diameter distribution regularities of 4 types of Pinus caribaea stand based on 4 probability density function: normal distribution, lognormal distribution, Weibull distribution and gamma distribution. The results showed that: (1) 4 kinds of stand diameter distribution curves were left skewness. The majorities of Pinus caribaea plants were medium and small diameter at breast height trees; (2) Weibull distribution function had better fitting effect for diameter distribution of Pinus caribaea and Acacia Taiwan mixed forest, gamma distribution had better fitting effect for diameter distribution of Pinus caribaea and Hainan muricata mixed forest, and Weibull distribution and gamma distribution had similar fitting effect for diameter distribution of Pinus caribaea pure forest. That was to say, for 4 stands Weibull distribution was the best, normal distribution was the worst, gamma distribution and lognormal distribution was general taking account of adaptability and flexibility.