Linking environment and forest trees production: a comparison of two approaches

Abstract

Two methods of studying forest species site-yield relationships have been tested by the Cemagref forestry division, Nogent-sur-Vernisson (France) and are presented, illustrated and compared. One method concerns the relationships between forest site type and yield, the other the autecologic approach. These methods can be applied in monospecific, even-aged and closed stands. In the first case, the site description is synthetic and corresponds to a forest site typology. In the second case, site description is analytic, so the site is described by different ecological parameters. The wood yield of the stand is characterised by a site index - top height at a given age - determined using a top height growth model. The comparison between the two approaches shows that both give useful results, with the same level of accuracy. The autecologic approach proves however to be the quickest and cheapest method.