Outline and examples for integrated evaluations of data from the intensive (Level II) monitoring of forest ecosystems in Germany

Data are collected at plots of the intensive forest monitoring programme (Level II monitoring) in Germany by the federal states and stored in a nation-wide database with the main task of contributing to a better understanding of the impacts of air pollutants and other environmental factors on forest ecosystems. Within this feasibility study these data were screened with the intention of outlining a conclusive concept for integrated evaluations. As a permanent challenge of complexly organised monitoring, the necessity of data control measures is underlined and a transparent documentation of univariate properties of key factors and basic relationships is advocated. Besides different statistical analyses, selected, aggregated, and derivative parameters have to undergo substantial check-ups of their information value with respect to risks associated with chemical or physical stress for trees and other biotic compartments of forest ecosystems. Examples of evaluations of different profundity are taken from the domains: crown condition, foliar element concentrations, increment of trees, ground floor vegetation, and chemical condition of the soil solution. Grounded on subject-specific sectoral considerations, concise sets of relevant (key) factors or composite factors should in future approaches-together with results from amending process-oriented modelling-be passed on to construct integrated models against the background of current hypotheses about stress in forest ecosystems, even on the national scale, and on reasonable sub-scales.