闽楠天然林林分结构规律的研究

Studies on the Stand Structure of Machilus Natural Forest in Fujian

利用闽楠天然林样地调查数据,对其林分结构规律进行研究。研究结果得出：闽楠天然林的林分直径分布呈中间高两边低的不对称山状曲线,可用威布尔概率密度函数进行拟合。在同一树高阶内,直径分布也基本呈不对称山状曲线,均可用对数正态分布函数、伽玛分布函数和威布尔概率密度函数进行拟合检验。林分树高分布呈贝塔分布,最高的树木为平均高的1.74倍,最矮的树木为平均高的0.29倍,变动系数31.88%,说明闽楠天然林林分树高的变动幅度较大。在同一径阶内,树高分布也是呈不对称山状曲线,用贝塔分布函数和威布尔分布函数拟合效果最好,其次是正态分布函数。径阶内的最小树高为径阶平均高的0.38-0.75倍,最大树高为径阶平均高的1.28-1.58倍,其树高变动幅度小于整个林分,且随径阶加大树高变动幅度逐渐缩小。研究闽楠天然林林分结构规律,对保护和利用其森林资源有着重要意义。

Based on the Sample-plot survey data in Fujian machilus natural forest, studies on it＇s stand structure. The Results showed that： The distribution of the diameter distribution on Fujian Machilus natural forest is present on a asymmetric montiform curve that the middle is higher than those of the sides. it can fitting by weibull distribution. In the same height grade, The distribution of the diameter distribution is also present on a asymmetric montiform curve, it can fitting by normal distribution, normal distribution and weibull distribu-tion. The distribution of the height distribution is present on beta distribution, the tallest tree is 1.74 times higher than the average, the shortest tree is 0.29 times higher than the average, the coefficient of variation is 31.88%, it illustrates that the amplitude of fluctuation of natural forest of Fujian machilus Stand height is big. In the same diameter grade, The distribution of the height distribution is present on a asymmetric montiform curve, it can fitting by beta distribution and weibull distribution for optimum results, and the second is normal distribution. And the minimum tree is 0.38-0.75 times higher than the average in the same diameter grade, the maximum tree is 1.28-1.58 times higher than the average, the amplitude of fluctuation of the height is less than the entire stand ＇s, and it will gradually narrowing with the diameter increasing. Studies on the stand structure of Fujian Machilus natural forest is important to protect and use its forest resources.