Influence of Soil Type on the Effects of Elevated Atmospheric CO2 and N Deposition on the Water Balance and Growth of a Young Spruce and Beech Forest

摘要: Sixteen open-top chambers, each equipped with two non-weighable gravity-drained lysi- meter compartments, were used to investigate the impacts of elevated atmospheric carbon dioxide (CO2) concentration and nitrogen (N) deposition on water relations growth young model forest ecosystems different types soils. The same vegetation a mixed spruce beech overstorey various herbs in understorey was planted all treatments both soils repacked top drainage layer. Four combinations applied four replicates each: ambient (370 cm 3 m )C O 2 +l ow (7 kg Nh 1 ) N deposition, CO2 + high (70 ha (590 low deposition. After canopy closure, treatment effects evapotranspiration during third year study very for On acidic sandy loam, enhanced (leaf biomass +21%, roots +27%) at reduced evapotranspira- tion (-9%). High increased aboveground even more strongly (+50%), but also (+16%). Together, had than additive fertilizer effect growth, while their compensated. calcareous loamy sand, not only tended enhance +17%, +20%), (+5%). this soil, stimulated by combination CO2, less (-6.5%) root into subsoil (-54%) decreased concentrations, contrast loam. influence soil observed ecosystem responses can be interpreted terms concept optimal resource allocation.