Modeling Effects of Overstory Density and Competing Vegetation on Tree Height Growth
Modeling Effects of Overstory Density and Competing Vegetation on Tree Height Growth
复制标题
模拟植被密度和竞争植被对树高生长的影响
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
A. Robinson
中科院分区：
文献类型：
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作者：
Christian Salas;A. R. Stage;A. Robinson
我们建立并评价了美国西北内陆地区道格拉斯冷杉的单株树高生长模型。该模型连续预测所有树木大小的生长，而不需要在幼年和成熟生长阶段的独立模型之间进行转换。该模型预测了盖层和林下植被竞争对树高生长的影响。我们的模型以树高而不是树龄作为预测变量，从而避免了立地指数的问题。场地效应是作为生态生境类型、海拔、坡向和坡度的函数而引入的。我们使用了6个数据集，总计3785棵树，分布在314个地块。数据和模型的结构表明，需要一种混合效应的非线性建模方法，在具有功率变换的线性微分方程中使用最大似然法。利用状态空间方法对模型的行为进行了分析。我们的结果表明，盖层密度和林下密度都影响高度生长，使管理者能够做出关于植被控制的明智决定。用于.S.CI。54(1)：107-122。
We developed and evaluated an individual-tree height growth model for Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) in the Inland Northwest United States. The model predicts growth for all tree sizes continuously, rather than requiring a transition between independent models for juvenile and mature growth phases. The model predicts the effects of overstory and understory vegetative competition on height growth. Our model requires attained height rather than tree age as a predictor variable, thereby avoiding the problems of site index. Site effects are introduced as a function of ecological habitat type, elevation, aspect, and slope. We used six data sets totaling 3,785 trees in 314 plots. The structure of the data and the model indicated the need for a mixed-effects, nonlinear modeling approach using maximum likelihood in a linear differential equation with a power transformation. Behavior of the model was analyzed using a state-space approach. Our results show that both overstory and understory density affect height growth, allowing a manager to make informed decisions about vegetation control. FOR .S CI. 54(1):107-122.