北京松山森林动态模拟研究

Simulation of forest dynamics at Songshan Mountain,Beijing.

运用改进的林隙模型ZELIG,对北京松山自然保护区的森林动态进行模拟和验证.结果如下:①模型能够合理地模拟华北暖温带阔叶林区森林的演替过程;群落先锋树种以山杨、白桦为主,100年后可达到相对稳定;建群种包括蒙古栎和油松,这两个种互为消长,栎类优势更显著.②模型较准确地量化模拟出树种组成和生物量,其中,建群种的模拟结果与观测值基本一致;先锋种模拟结果总体优于单个树种的模拟.③对松山自然保护区的森林演替趋势进行预测:不同的初始状态对森林组成和生物量有较大影响,但系统都有回复到同一状态的趋势,且起始于蒙古栎林比起始于油松林回复速度快;有林地中的伴生种受压状态明显;起始于蒙古栎林时生物量均值最大,而起始于油松林时最稳定.

Using modified gap model ZELIG, the forest dynamics was simulated at Songshan Mountain National Nature Reserve. And the results were showed as the followings： 1 ） the model can reasonably describe the long-term forest succession in a warm temperate zone of north China. Populus davidiana and Betula platyphylla are the pioneer tree species in the succession process. The forests would come to be comparative stable and dominated by Quercus mortgolica and Pinus tabulaeformis after 100 years. The two species are mutual increase and decrease, however Q. mongolica is predominating; 2） the model can well quantify the composition and biomass of tree species. The simulated results of model were consistent with the observed data. Pioneer species as whole were modeled more exactly than as concrete species. The simulated dynamic trends of forests at Songshan Mountain were showed as the followings： 1 ） different initial status strongly affected the species composition and biomass, although systems would restore the identical status. Succession from Q. mongolica stand restored faster than that from P. tabulaeformis ; 2） the associated tree species in forest land was stressed evidently; 3） the stands which were developed from Q. mongolica stands owned the highest mean of biomass, and those developed from P. tabulaeformis were most stable. Some opinions about how to reserve and restore the forests were derived from the results.