Long‐term fertilization of a boreal Norway spruce forest increases the temperature sensitivity of soil organic carbon mineralization. Issue 16 (25th November 2013)

• Record Type: Journal Article
• Authors: Coucheney, Elsa; Strömgren, Monika; Lerch, Thomas Z.; Herrmann, Anke M.
• Is Part Of: Ecology and evolution. Volume 3:Issue 16(2013)
• Page Start: 5177
• Page End: 5188
• Publication Date: 2013-11-25
• Subjects: Boreal soils -- microbial community -- nutrient fertilization -- soil organic carbon -- temperature sensitivity -- warming; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.895
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Boreal ecosystems store one‐third of global soil organic carbon (SOC) and are particularly sensitive to climate warming and higher nutrient inputs. Thus, a better description of how forest managements such as nutrient fertilization impact soil carbon (C) and its temperature sensitivity is needed to better predict feedbacks between C cycling and climate. The temperature sensitivity of in situ soil C respiration was investigated in a boreal forest, which has received long‐term nutrient fertilization (22 years), and compared with the temperature sensitivity of C mineralization measured in the laboratory. We found that the fertilization treatment increased both the response of soil in situ CO2 effluxes to a warming treatment and the temperature sensitivity of C mineralization measured in the laboratory (Q10 ). These results suggested that soil C may be more sensitive to an increase in temperature in long‐term fertilized in comparison with nutrient poor boreal ecosystems. Furthermore, the fertilization treatment modified the SOC content and the microbial community composition, but we found no direct relationship between either SOC or microbial changes and the temperature sensitivity of C mineralization. However, the relation between the soil C:N ratio and the fungal/bacterial ratio was changed in the combined warmed and fertilized treatment compared with the other treatments, which suggest that strong interaction mechanisms may occur between nutrient input and warming in boreal soils. Further research is needed to unravel into more details in how far soil organic matter and microbial community composition changes are responsible for the change in the temperature sensitivity of soil C under increasing mineral N inputs. Such research would help to take into account the effect of fertilization managements on soil C storage in C cycling numerical models. Abstract : Boreal ecosystems store one‐third of global soil organic carbon and are particularly sensitive to climate warming. In this study, we found that long‐term nutrient fertilization increases the temperature sensitivity of soil organic carbon in those ecosystems, but no direct relationship was found with the modification of soil organic matter characteristics nor microbial community composition due to the fertilization treatment. This research would help to take into account the effect of fertilization managements on soil carbon storage under warmer climate in carbon cycling numerical models.