天然红松阔叶林径级结构模拟

以天然红松阔叶林为研究对象，设置了4块1 hm²样地，利用负指数模型、修正指数模型、限定混合Weibull分布模型及q值法进行径级结构模拟。结果表明，4块不同类型样地的径级分布均呈反“J”形，森林更新良好；指数模型整体上低估了林木株数，限定混合Weibull分布模型则高估了林木株数，而修正指数模型整个径阶范围内与实际情况较为接近，模拟效果最好，表明修正指数模型更适合天然红松阔叶林径级结构的模拟；4块不同林分的q值为1.19~1.33，说明q值法对于天然红松阔叶林的直径分布的表达效果较好。

Modeling Diameter Distribution of Natural Broadleaved-Korean Pine Mixed Forest

Four 1 hm2 plots were set up in a natural broadleaved-korean pine mixed forest, and the negative exponential model, modified exponential model, finite mixture Weibull distribution model and constant ratio q were used to model the diameter distribution. Results showed that in the 4 plots of different forest types, the diameter distribution of the trees all exhibited inverse J-shape, which meant that understory regeneration was relatively good. The overall number of trees were underestimated and overestimated by negative exponential model and finite mixture Weibull distribution model, respectively. The modified exponential model was more suitable for modeling the diameter distribution of natural broadleaved-korean pine mixed forest because it could predict the number of trees more exactly in the entire range of diameter classes. The diameter q value of the 4 plots of different forest types were between 1.19 and 1.33, which meant that it was better for expressing the diameter distribution of natural broadleaved-korean pine mixed forest.