MODELING FOREST GROWTH .1. CANONICAL APPROACH

The paper proposes a canonical modeling approach as a useful tool for the analysis of complex phenomena in forestry. In contrast to most tra ditional models in forestry, this approach offers the advantage that n o assumptions about the mechanisms of the underlying physiological pro cesses and their translation into mathematical functions are necessary . Instead, the structure of the describing equations is derived direct ly from qualitative information about the processes that govern the ph enomenon with methods of general approximation theory. All parameters of the model have a clearly defined meaning and are, at least in princ iple, measurable from standard experiments. The companion paper illust rates the canonical modeling process with a specific, quantitative ana lysis of biomass budgets of Scots pine (Pinus syluestris). It shows ho w information about biomass budgets is translated into a specific mode l, how the model parameters are derived from experimental data on comp artment sizes and fluxes, and what kinds of questions can be analyzed. It is demonstrated that none of the typical assumptions about growth rates, relationships between roots and shoots, or allometry are made, but rather that all these phenomena are produced by the model as outpu t.