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

• Published in: Water, air, and soil pollution air, and soil pollution, 2001-03, Vol.126 (3-4), p.271-290
• Main Authors: SONNLEITNER, Marion A, GÜNTHARDT-GOERG, Madeleine S, BUCHER-WALLIN, Inga K, ATTINGER, Werner, REIS, Sybille, SCHULIN, Rainer
• Format: Article
• Language: English
• Subjects: Acidic soils; Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Biological and medical sciences; Biomass; Carbon dioxide; Effects; Environmental monitoring; Environmental science; Evapotranspiration; Fagus; Forest ecosystems; Forestry; Fundamental and applied biological sciences. Psychology; General forest ecology; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology; Leaves; Loam; Nitrates; Picea; Plant growth; Plants and fungi; Resource allocation; Roots; Sandy loam; Sandy soils; Soil types; Soils; Studies; Subsoils; Terrestrial ecosystems; Water balance; Water relations
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1023/A:1005244916109

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