长白山地区天然林林木年龄与胸径的变动关系

Variable Relationship between Tree Age and Diameter at Breast Height for Natural Forests in Changbai Mountains

受树种多、空间分布复杂和发育阶段各异等的影响,天然林中树木年龄的测定难度很大。以吉林省汪清林业局的天然云冷杉针阔混交林为研究对象,使用8块皆伐标准地的1678株标准木数据,从林木胸径随树龄的变动和相同径阶林木的年龄差异两个方面对林分年龄进行估测。结果表明,幂函数、抛物线方程可以较好地描述胸径生长;幂函数、指数函数、抛物线和对数函数可以较好地描述径阶平均年龄与径阶的关系。建立了7个主要树种的胸径与树龄的方程,可以提高当地的生长与收获模型的精度;相同径阶林木年龄的差异与其生长的环境、空间位置以及周围林木的竞争等有关。

It is very difficult to measure the age of trees in natural forest exactly because of its multiple tree species, complex spatial distribution, different stages of development, and so on. In this study, eight clear-cutting plots in the natural spruce-fir coniferous and broad-leaved mixed stands, located in Wangqing of Jilin Province, were used as the research object. The relationships between tree age and diameter at breast height （DBH） were analyzed in terms of the data of 1678 sample trees. Results show that DBH growth can be well described by power function and parabolic equation, and the relationships between average age of diameter class and diameter class can be well described by power function, exponential function, parabolic equation, and logarithmic function. Equations between DBH and tree age of seven tree species were established, which could improve the accuracy of model for growth and yield for the local forests. The difference in tree age of the same diameter class was related with growing environment, spatial location, competition with trees around.