Process-based size-class distribution model of trees within forest plantations: A hierarchical modeling approach

摘要

Prediction of stand structure, and how it varies with climate, disturbance and silviculture, can assist the design of adaptation options to climate change, aid silviculture response to storm damage or pest attack, and help stand managers meet product delivery schedules and maximize wood value. Making these predictions with process-based models typically requires detailed data on the existing tree population structure from which to initiate projection, or alternatively highly complex, and difficult to parameterize, models of inter-tree competition. This paper introduces a hierarchical modeling approach to address this problem. In this approach, the stand-level outputs of a process-based model, CABALA, are disaggregated among individual trees within a stand according to simple rules to provide individual tree sizes and growth trajectories. The model, designed for single-species, evenly-spaced stands, is based on a number of assumptions including: stand level allometrics can be scaled to individual trees; above-ground competition for space and resources can be used as a guide to overall inter-tree competition; trees within a stand start with a distribution of sizes as well as variation in intrinsic productive potential.