22
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: not found
      • Article: not found

      The fate of photosynthetically-fixed carbon inLolium perennegrassland as modified by elevated CO2and sward management

      , , , ,   , ,
      New Phytologist
      Wiley

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Prediction of the impact of climate change requires the response of carbon (C) flow in plant-soil systems to increased CO(2) to be understood. A mechanism by which grassland C sequestration might be altered was investigated by pulse-labelling Lolium perenne swards, which had been subject to CO(2) enrichment and two levels of nitrogen (N) fertilization for 10 yr, with (14)CO(2). Over a 6-d period 40-80% of the (14)C pulse was exported from mature leaves, 1-2% remained in roots, 2-7% was lost as below-ground respiration, 0.1% was recovered in soil solution, and 0.2-1.5% in soil. Swards under elevated CO(2) with the lower N supply fixed more (14)C than swards grown in ambient CO(2), exported more fixed (14)C below ground and respired less than their high-N counterparts. Sward cutting reduced root (14)C, but plants in elevated CO(2) still retained 80% more (14)C below ground than those in ambient CO(2). The potential for below-ground C sequestration in grasslands is enhanced under elevated CO(2), but any increase is likely to be small and dependent upon grassland management.

          Related collections

          Most cited references49

          • Record: found
          • Abstract: not found
          • Article: not found

          Carbon input by plants into the soil. Review

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Variable effects of nitrogen additions on the stability and turnover of soil carbon.

            Soils contain the largest near-surface reservoir of terrestrial carbon and so knowledge of the factors controlling soil carbon storage and turnover is essential for understanding the changing global carbon cycle. The influence of climate on decomposition of soil carbon has been well documented, but there remains considerable uncertainty in the potential response of soil carbon dynamics to the rapid global increase in reactive nitrogen (coming largely from agricultural fertilizers and fossil fuel combustion). Here, using 14C, 13C and compound-specific analyses of soil carbon from long-term nitrogen fertilization plots, we show that nitrogen additions significantly accelerate decomposition of light soil carbon fractions (with decadal turnover times) while further stabilizing soil carbon compounds in heavier, mineral-associated fractions (with multidecadal to century lifetimes). Despite these changes in the dynamics of different soil pools, we observed no significant changes in bulk soil carbon, highlighting a limitation inherent to the still widely used single-pool approach to investigating soil carbon responses to changing environmental conditions. It remains to be seen if the effects observed here-caused by relatively high, short-term fertilizer additions-are similar to those arising from lower, long-term additions of nitrogen to natural ecosystems from atmospheric deposition, but our results suggest nonetheless that current models of terrestrial carbon cycling do not contain the mechanisms needed to capture the complex relationship between nitrogen availability and soil carbon storage.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Functional responses of plants to elevated atmospheric CO2- do photosynthetic and productivity data from FACE experiments support early predictions?

                Bookmark

                Author and article information

                Journal
                NPH
                New Phytologist
                Wiley
                0028646X
                14698137
                March 2007
                March 2007
                : 173
                : 4
                : 766-777
                Article
                10.1111/j.1469-8137.2007.01966.x
                17286825
                01432cfd-9e80-41f0-a287-afec565b16ec
                © 2007

                http://doi.wiley.com/10.1002/tdm_license_1.1

                History

                Comments

                Comment on this article