|Hauhs, M; Kastner-Maresch, A; Rost-Siebert, K: A model relating forest growth to ecosystem-scale budgets of energy and nutrients, Ecological Modelling, 83, 229-243 (1995), doi:10.1016/0304-3800(95)00101-Z|
In this model of a forest ecosystem the height growth strategy of individual trees is linked to ecosystem-scale budgets of energy and a growth-limiting nutrient. The model spans from the individual tree to stand scales up to one hectare with a yearly time resolution. Competition among trees above-ground for light and below-ground for nutrients is used to model adaptation to external input fluxes over several tree generations. The competition among leaves and roots is modelled by a representation of the geometrical structures and a functional balance among the corresponding biomass compartments of trees. Dead biomass is decomposed in relation to its initial quality and nutrients are thus recycled into the root zone. The model is used (i) to reconstruct biomass accumulation and stand structure for even-aged and thinned stands and (ii) to study the evolutionary stability of observed height growth curves as a function of external input fluxes characterizing the physical environment of the stand in an abstract manner. Empirically, height growth has been widely established as a site-specific growth potential index for Norway spruce stands (Picea abies Karst.) in Germany. The model is used to reconstruct typical height growth curves. Such an assessment of the initial potential in growth responses is a prerequisite for studying the transient growth response to an external disturbance in the nutrient budget of the stand, e.g. in stands receiving atmospheric deposition.