Bayesian classification of vegetation types with Gaussian mixture density fitting to indicator values
Article first published online: 24 FEB 2009
2007 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 18, Issue 4, pages 605–612, August 2007
How to Cite
Witte, J.-P. M., Wójcik, R. B., Torfs, P. J.J.F., de Haan, M. W.H. and Hennekens, S. (2007), Bayesian classification of vegetation types with Gaussian mixture density fitting to indicator values. Journal of Vegetation Science, 18: 605–612. doi: 10.1111/j.1654-1103.2007.tb02574.x
- Issue published online: 24 FEB 2009
- Article first published online: 24 FEB 2009
- Received 1 August 2006; Accepted 26 January 2007
- Environmental Impact Assessment;
- Predictive vegetation model
Question: Is it possible to mathematically classify relevés into vegetation types on the basis of their average indicator values, including the uncertainty of the classification?
Location: The Netherlands.
Method: A large relevé database was used to develop a method for predicting vegetation types based on indicator values. First, each relevé was classified into a phytosociological association on the basis of its species composition. Additionally, mean indicator values for moisture, nutrients and acidity were computed for each relevé. Thus, the position of each classified relevé was obtained in a three-dimensional space of indicator values. Fitting the data to so called Gaussian Mixture Models yielded densities of associations as a function of indicator values. Finally, these density functions were used to predict the Bayesian occurrence probabilities of associations for known indicator values. Validation of predictions was performed by using a randomly chosen half of the database for the calibration of densities and the other half for the validation of predicted associations.
Results and Conclusions: With indicator values, most reléves were classified correctly into vegetation types at the association level. This was shown using confusion matrices that relate (1) the number of relevés classified into associations based on species composition to (2) those based on indicator values. Misclassified relevés belonged to ecologically similar associations. The method seems very suitable for predictive vegetation models.