西双版纳热带林生长动态模型及可持续经营模拟

Modeling growth dynamics and simulation of forest management in tropical forests of southwestern China.

为研究中国热带森林的可持续经营方式 ,在中国西南西双版纳的山地雨林中设置了 1 2块固定观测样地 ,并在定期观测数据基础上估计林分生长量、林木进界率与径阶保留率等 .据此建立林分自然生长的径级分布模型 ,择伐作业对保留木影响的损伤模型 ,采伐后由于林窗效应对林木生长影响的经验模型 ,进界生长模型等热带森林生长动态数学模型并估计了林分初始状态、林分动态转移因子等参数 .以森林经营实践的内在逻辑和关键过程为基础设计了森林生长和经营模拟系统的框架概念 ,应用面向对象的方法设计系统的各个独立程序模块 ,用VBA语言与EXCEL结合开发了系统应用软件 .应用本模拟系统对西双版纳热带林的择伐经营模式作了所有可能参数组合的模拟经营实验 。

Permanent plots in the mountain tropical rain forests in Xishuangbanna, SW China, were set and observations were conducted to estimate growth, ingrowth and mortality. Based on the findings, stand dynamics was expressed by the diameter class distribution model, a separate regression for ingrowth was incorporated. Logging damages in relation to logging intensity were estimated by a regression model based on data from other parts of the tropics; the effect of canopy opening by logging on the growth of the remaining stands was likewise estimated. Parameters of stand original state, transformation factors and ratio of commercial timber were also estimated. A simulation system for forest management was developed by integrating these models and parameters in programming with Visual Basic to convert the conceptual system into executable software. The simulator was used to investigate different management scenarios for sustainability of timber production in the tropical forests of Xishuangbanna. Simulation experiment was conducted with all possible combinations of parameters. Based on these results, the most suitable criteria and standard for the sustainable forest management were suggested.