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Free keywords:
SOIL ORGANIC-MATTER; ELEVATED CO2; ATMOSPHERIC CO2; ECOSYSTEM RESPONSES;
N AVAILABILITY; LOLIUM-PERENNE; PLANT-GROWTH; CARBON; TEMPERATURE;
CONSEQUENCESBiomass; Climate warming; Elevated CO(2); Nitrogen; Grassland species;
Abstract:
Few studies have investigated whether responses to nutrient supply of mixed plant communities change under combined elevated CO(2) and climate warming. In this study we analyzed the response of constructed temperate grassland communities to five levels of nitrogen (N) supply, ranging from 0 to 150 kg N ha(-1), under two climate scenarios. Biomass of the plant communities responded positively to N supply in the current climate, but was insensitive to N supply in the future climate. This altered response was not the result of a changing response from a single species, but all species seemed to contribute to it. The weaker response in the future climate was caused by changes in N uptake rather than by changes in nitrogen use efficiency, as community N stocks showed the same response pattern as community biomass. Climate change apparently modified the relation between fertilizer N addition and plant available N.
