Diameter and height growth curves for widely-spaced trees in European agroforestry

Predicting timber volume can be important for decision- making. Conventional forest growth models are generally based on mensuration data acquired in fully stocked homogeneous tree stands, and do not consider the wide spacings often adopted in European agroforestry. In order to test the possibility of adapting conventional forestry growth models, diameter and height growth were measured on widely spaced trees. Parameters of a Gompertz double exponential function were adjusted for several tree species planted at wide spacings. Spacing, vegetation control, and individual tree shelters affected the parameters. At wide spacings, the asymptote for diameter growth was larger, and the asymptote for height growth smaller, compared to conventional forestry.