The author provides an introduction to the issues surrounding ecosystem analysis in relation to widespread forest damage. Through extensive data analyses and models, not only is the mathematical theory clearly applied, but concrete hypotheses regarding the causes of novel forest damage are also tested, and the results of multivariate model calculations are interpreted. Using numerous graphics, the author makes a unique attempt to convey the theory of multivariate data analysis to an audience trained in environmental or forestry sciences in understandable steps. Contents include: Natural and novel forest damage, multidimensional ecological model, multidimensional representations of ecosystem parameters (discriminant analysis, canonical correlation analysis, regression, principal component analysis, factor analysis), mathematical appendix (including vector space, matrix).