title: Modelling tree roots in mixed forest stands by inhomogeneous marked Gibbs point processes.
abstract: The aim of the paper is to apply point processes to root data modelling. We propose a new approach to parametric inference when the 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 neighbourhood 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 not independent.
authors: Ulm University, Institute of Stochastics, Helmholtzstr. 18, 89069 Ulm, Germany. stefanie.eckel@uni-ulm.de
authors: Stefanie
authors: S
authors: Eckel
authors: Frank
authors: F
authors: Fleischer
authors: Pavel
authors: P
authors: Grabarnik
authors: Marian
authors: M
authors: Kazda
authors: Aila
authors: A
authors: Särkkä
authors: Volker
authors: V
authors: Schmidt
mesh_terms: D000383:Agriculture / Q000379:methods*; D001699:Biometry / Q000379:methods*; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D008954:Models, Biological; D015233:Models, Statistical; D018517:Plant Roots / Q000254:growth & development*; D014197:Trees / Q000254:growth & development*