Age-related decline in forest production: modelling the effects of growth limitation, neighbourhood competition and self-thinning
Age-related decline in forest production: modelling the effects of growth limitation, neighbourhood competition and self-thinning
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DOI：
10.1111/j.0022-0477.2004.00911.x
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发表时间：
2004-10-01
影响因子：
5.5
通讯作者：
Grimm, V
中科院分区：
文献类型：
--
作者：
Berger, U;Hildenbrandt, H;Grimm, V
1在生长的林分中，地上净初级生产量在林分发展的早期达到峰值，然后下降。这种下降的原因还没有得到很好的理解，但假设包括生理和生理生态影响，以及由于邻近树木之间的局部竞争造成的林分结构变化。在这里，我们研究的综合效应的内在生长限制的个别树木，生长限制由于邻居的竞争，和selfthining.3我们使用一个基于个体的模型来分析木材生产的一个红树林物种描述的S形生长函数，和两个假设的物种的指数或线性增长。该模型再现了下降的所有物种的调查，即使当个人的增长率并没有成为limited.4我们的结论是，个人，S形生长曲线是足够的，但没有必要解释生产下降的天然林，邻里竞争是相当活跃。虽然通过邻里竞争的增长减少是在开始的主要过程，不平衡的木材损失占主导地位的后期下降。
1 In growing forest stands, above-ground net primary production peaks early in stand development and then declines. The causes for this decline are not yet well understood, but hypotheses include physiological and ecophysiological effects, as well as changes in stand structure due to local competition among neighbouring trees.2 The majority of existing studies address mono-causal explanations of this decline. Here we study the combined effects of intrinsic growth limitation of individual trees, growth limitation due to neighbourhood competition, and self-thinning.3 We use an individual-based model to analyse forest wood production of a mangrove species described by a sigmoidal growth function, and two hypothetical species with exponential or linear growth. The model reproduces a decline for all species investigated, even when individual growth rates did not become limited.4 We conclude that individual, sigmoidal growth curves are sufficient but not necessary to explain the production decline in natural forests where neighbourhood competition is appreciably active.5 We show that the causes for production decline change during forest development. Whereas growth reduction through neighbourhood competition is the main process at the beginning, imbalanced wood loss dominates the later stage of the decline.