Potential of temporal and spatial analysis techniques as tools for exploring changes in forest site productivity and following environmental interactions : Finnish-German comparative study
The main target of this study is the detection of possible changes in forest site productivity and interaction with changes in the environmental conditions by the use of temporal and spatial analysis techniques. Height and radial increments of Norway spruce (Picea abies L. Karst) and Scots pine (Pinus sylvestris L.) were used in to describe and model the sites with clear change of site quality, but also to find relationships between spatial patterns and space-time trajectories in forest growth deviations and potential causes of these changes. Investigated potential causes of growth trends related to site productivity changes like weather (basically air temperature and precipitation and subsequent derived parameters like water balance) and seasonal climate change, increasing CO2, foliar nutrition, nitrogen deposition, were assessed for the complete data set of 33 sites in Finland and 32 sites in Germany. The most important investigated anthropogenic influences on site productivity changes were the deposition of nitrogen (oxidized and reduced), CO2 as well as climate change. There was a quantitative difference in regard to geographical locations and tree species behave to a changing environment. The results suggested that the observed increase in site productivity under boreal conditions was due mainly to climate (air temperature change), since growth is constrained by the duration of the growing season. Moreover, central European growth acceleration was mainly due to a nitrogen fertilization effect as well as to precipitation (sites where air temperature change induced drought stress in summer months).
Standortsproduktivität, räumliche Analyse, Blattnahrung, Stickstoff-Deposition, Dendroökologie, site productivity, spatial analysis, climate change, foliar nutrition, nitrogen deposition, dendrochronology, dendroecology
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