Modelling tree roots in mixed forest stands by inhomogeneous marked Gibbs point processes.

Artikel i vetenskaplig tidskrift, 2009

The aim of the paper is to apply point processes to root data modelling. We propose a new approach to parametric inference when data are inhomogeneous replicated marked point patterns.} We generalize Geyer's saturation point process to a model which combines inhomogeneity, marks and interaction between the marked points. Furthermore, the inhomogeneity influences the definition of the neighborhood of points. Using the maximum pseudolikelihood method, this model is then fitted to root data from mixed stands of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) to quantify the degree of root aggregation in such mixed stands. According to the analysis there is no evidence that the two root systems are dependent.