Modelling impacts of changes in carbon dioxide concentration, climate and nitrogen deposition on growth and carbon sequestration of Intensive Forest Monitoring plots in Europe.

31 Wamelink, G.W.W. Wieggers, R. Reinds, G.J. Kros,J. Mol-Dijkstra, J. P. van Oijen, M. de Vries, W. 2009 Modelling impacts of changes in carbon dioxide concentration, climate and nitrogen deposition on growth and carbon sequestration of Intensive Forest Monitoring plots in Europe. Forest Ecology and Management climate change, biomass, precipitation, soil, nitrogen cycling, nutrients, biomass accumulation, carbon sequestration, temperature Changes in the Earthâ��s atmosphere are expected to influence the growth and therefore carbon accumulation of European forests. We identify three major changes: (1) a raise in carbon dioxide concentration, (2) climate change, resulting in higher temperatures and changes in precipitation and (3) a decrease in nitrogen deposition. We adjusted and applied the hydrological model Watbal, the soil model SMART2 and the vegetation model SUMO2 to asses the effect of expected changes in the period 1990 up to 2070 on the carbon accumulation in trees and soils of 166 European forest plots. The models were parameterized using measured soil and vegetation parameters and site-specific changes in temperature, precipitation and nitrogen deposition. The carbon dioxide concentration was assumed to rise uniformly across <st1:place w:st="on">Europe</st1:place>. The results were compared to a reference scenario consisting of a constant CO2 concentration and deposition scenario. The temperature and precipitation scenario were a repeatment of the period between 1960 and 1990. All scenarios were compared to the reference scenario for biomass growth and carbon sequestration for both the soil and trees.<o:p></o:p> The predicted effects of changes in climate, CO2 concentration and nitrogen deposition on carbon sequestration by trees depend largely on tree species and location (latitude). The assumed decrease in nitrogen deposition causes a decrease of carbon accumulation all over <st1:place w:st="on">Europe</st1:place> and for all modelled tree species. A raise in carbon dioxide concentration gives a raise in carbon accumulation all over <st1:place w:st="on">Europe</st1:place>. Climate change gives a mixed result, with a decrease in carbon accumulation in the South of Europe and an increase in the North. When the scenarios are combined, an increase in biomass accumulation is predicted at most of the sites, with a raise in growth rate mostly between 0% and 100%. The predicted effects of a change in climate, CO2 concentration and nitrogen deposition depends on soil carbon sequestration is generally lower than on carbon sequestration by the trees but the magnitude is similar and also the dependence on location (latitude). A net carbon release was predicted at several sites in the south due to the effect of climate change. Overall, we conclude that where nitrogen deposition was a major driver for a change in forest growth in the past, it is climate change and to a lesser extent CO2 change that will influence forest growth in the future.<o:p></o:p>