A Parsimonious Dynamic Stand Model for Interior Spruce in British Columbia
A Parsimonious Dynamic Stand Model for Interior Spruce in British Columbia
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不列颠哥伦比亚省室内云杉的简约动态支架模型
DOI：
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发表时间：
2011
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影响因子：
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通讯作者：
Oscar García
中科院分区：
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作者：
Oscar García
利用加拿大不列颠哥伦比亚省亚北方云杉生物地理气候带的永久样地数据，建立了以云杉为主、平均树龄、自然和人工林分的全林分生长模型Scube。现有数据有限，没有关于成熟种植林分或间伐处理的信息。一个简约的模型设计，结合林分动态的知识和其他森林的经验，使对观察到的行为的逻辑再现和对其他条件的合理推断成为可能。Scube由四个微分方程组成，描述了四个状态变量的演变：顶高、每公顷树数、基面积和林分闭合指标。封闭和场地占用的概念驱动了年轻林分的行为和对间伐的反应。通过数个残差函数的数值优化估计参数，反映了不同的投影区间类型和加权策略。各种标准之间的估计差异很小。通过在没有干扰时保持不变的表达式，方便了计算。这些方法推广了代数差分方法和相关的森林建模技术，将它们与标准动力系统理论联系起来。
A whole-stand growth model, Scube, was developed for spruce-dominated, even-aged, natural and planted stands, using permanent sample plot data from the sub-boreal spruce biogeoclimatic zone of British Columbia, Canada. Available data were limited, with no information on mature planted stands or thinning treatments. A parsimonious model design, incorporating knowledge of stand dynamics and experience from other forests, made possible a logical reproduction of observed behavior and plausible extrapolations to other conditions. Scube consists of a system of four differential equations, describing the evolution of four state variables: top height, trees per hectare, basal area, and a stand closure indicator. Concepts of closure and site occupancy drive the behavior of young stands and the response to thinning. Parameters were estimated through numerical optimization of several residual functions, reflecting different projection interval types and weighting strategies. Differences in estimates among the various criteria were small. Calculations are facilitated through expressions that remain invariant in the absence of disturbances. The methods generalize the algebraic difference approach and related forest modeling techniques, linking them to standard dynamical systems theory.