Trevisani, M.; Causin, R.; Montecchio, L.; Kastner, C.; Heumann, Christian (1999): Analysing the relationship between ectomycorrhizal infection and forest decline using marginal models. Sonderforschungsbereich 386, Discussion Paper 143




This statistical survey originates from the problem of discovering which relationship exists between root ectomycorrhizal infection and health status of forest plants. The sampling scheme takes observations from roots that come from sectors around the tree resulting in a hierarchical association structure of the observations. Marginal regression models are used to analyze the mean effect of the ectomycorrhizal state on a response variable proxy for the health degree of the plants.