Climate Change Affects Carbon Allocation to the Soil in Shrublands
Citation
Josep Penuelas, Alwyn Sowerby, Nina N Joosten, Albert Tietema, Bridget A Emmett, Marc Estiarte, Antonie Gorissen, and Claus Beier, Climate Change Affects Carbon Allocation to the Soil in Shrublands: .
Summary
Climate change may affect ecosystem functioning through increased temperatures or changes in precipitation patterns. Temperature and water availability are important drivers for ecosystem processes such as photosynthesis, carbon translocation, and organic matter decomposition. These climate changes may affect the supply of carbon and energy to the soil microbial population and subsequently alter decomposition and mineralization, important ecosystem processes in carbon and nutrient cycling. In this study, carried out within the cross-European research project CLIMOOR, the effect of climate change, resulting from imposed manipulations, on carbon dynamics in shrubland ecosystems was examined. We performed a 14C-labeling experiment to [...]
Summary
Climate change may affect ecosystem functioning through increased
temperatures or changes in precipitation patterns. Temperature and water
availability are important drivers for ecosystem processes such as
photosynthesis, carbon translocation, and organic matter decomposition.
These climate changes may affect the supply of carbon and energy to the
soil microbial population and subsequently alter decomposition and
mineralization, important ecosystem processes in carbon and nutrient
cycling. In this study, carried out within the cross-European research
project CLIMOOR, the effect of climate change, resulting from imposed
manipulations, on carbon dynamics in shrubland ecosystems was examined.
We performed a 14C-labeling experiment to probe changes in net carbon
uptake and allocation to the roots and soil compartments as affected by
a higher temperature during the year and a drought period in the growing
season. Differences in climate, soil, and plant characteristics resulted
in a gradient in the severity of the drought effects on net carbon
uptake by plants with the impact being most severe in Spain, followed by
Denmark, with the UK showing few negative effects at significance levels
of p ≤ 0.10. Drought clearly reduced carbon flow
from the roots to the soil compartments. The fraction of the 14C fixed
by the plants and allocated into the soluble carbon fraction in the soil
and to soil microbial biomass in Denmark and the UK decreased by more
than 60%. The effects of warming were not significant, but, as with the
drought treatment, a negative effect on carbon allocation to soil
microbial biomass was found. The changes in carbon allocation to soil
microbial biomass at the northern sites in this study indicate that soil
microbial biomass is a sensitive, early indicator of drought- or
temperature-initiated changes in these shrubland ecosystems. The reduced
supply of substrate to the soil and the response of the soil microbial
biomass may help to explain the observed acclimation of CO 2 exchange in
other ecosystems. Published in Ecosystems, volume 7, issue 6, on pages
650 - 661, in 2004.
