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Research article2009Peer reviewed

Partitioning of soil respiration into its autotrophic and heterotrophic components by means of tree-girdling in old boreal spruce forest

Högberg, Peter; Bhupinderpal-Singh, ; Ottosson Löfvenius, Mikaell; Nordgren, Anders

Abstract

Forests accumulate much less carbon than the amount fixed through photosynthesis because of an almost equally large opposing flux Of CO(2) from the ecosystem. Most of the return flux to the atmosphere is through soil respiration, which has two major sources, one heterotrophic (organisms decomposing organic matter) and one autotrophic (roots, mycorrhizal fungi and other root-associated microbes dependent on recent photosynthate). We used tree-girdling to stop the flow of photosynthate to the belowground system, hence, blocking autotrophic soil activity in a 120-yr-old boreal Picea abies forest. We found that at the end of the summer, two months after girdling, the treatment had reduced soil respiration by up to 53%. This figure adds to a growing body of evidence indicating (t-test, d.f. = 7, p < 0.05) that autotrophic respiration may contribute more to total soil respiration in boreal (mean 53 +/- 2%) as compared to temperate forests (mean 44 +/- 3%). Our data also suggests that there is a seasonal hysteresis in the response of total soil respiration to changes in temperature. We propose that this reflects seasonality in the tree below-ground carbon allocation. (C) 2009 Elsevier B.V. All rights reserved.

Keywords

Boreal forest; Carbon balance; Soil respiration; Tree-girdling

Published in

Forest Ecology and Management
2009, Volume: 257, number: 8, pages: 1764-1767 Publisher: ELSEVIER SCIENCE BV

      SLU Authors

        • Nordgren, Anders

          • Department of Forest Ecology, Swedish University of Agricultural Sciences

        UKÄ Subject classification

        Environmental Sciences related to Agriculture and Land-use
        Renewable Bioenergy Research

        Publication identifier

        DOI: https://doi.org/10.1016/j.foreco.2009.01.036

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/49997