Nitrogen, organic carbon and sulphur cycling in terrestrial ecosystems: linking nitrogen saturation to carbon limitation of soil microbial processes

0396982 - BC 2014 RIV NL eng J - Článek v odborném periodiku
Kopáček, Jiří - Cosby, B. J. - Evans, C. D. - Hruška, J. - Moldan, F. - Oulehle, F. - Šantrůčková, H. - Tahovská, K. - Wright, R. F.
Nitrogen, organic carbon and sulphur cycling in terrestrial ecosystems: linking nitrogen saturation to carbon limitation of soil microbial processes.
Biogeochemistry. Roč. 115, 1-3 (2013), s. 33-51. ISSN 0168-2563. E-ISSN 1573-515X.
[BIOGEOMON : international symposium on ecosystem behavior /7./. Northport, 15.07.2012-20.07.2012]
Grant CEP: GA ČR(CZ) GAP504/12/1218
Institucionální podpora: RVO:60077344
Klíčová slova: nitrogen * carbon * sulphur * acidification * forest soil * modelling
Kód oboru RIV: DJ - Znečištění a kontrola vody
Impakt faktor: 3.730, rok: 2013

Elevated and chronic nitrogen (N) deposition to N-limited terrestrial ecosystems can lead to nitrogen saturation, with resultant ecosystem damage and leaching of nitrate (NO₃^–) to surface waters. Present-day N deposition, however, is often a poor predictor of NO₃^– leaching, and the pathway of the ecosystem transition from N-limited to N-saturated remains incompletely understood. The dynamics of N cycling are intimately linked to the associated carbon (C) and sulphur (S) cycles. We hypothesize that N saturation is associated with shifts in the microbial community, manifest by a decrease in the fungi-to-bacteria ratio and a transition from N to C limitation. Three mechanisms could lead to lower amount of bioavailable dissolved organic C (DOC) for the microbial community and to C limitation of N-rich systems: (1) Increased abundance of N for plant uptake, causing lower C allocation to plant roots; (2) chemical suppression of DOC solubility by soil acidification; and (3) enhanced mineralisation of DOC due to increased abundance of electron acceptors in the form of SO₄^2– and NO₃^– in anoxic soil micro-sites. Here we consider each of these mechanisms, the extent to which their hypothesised impacts are consistent with observations from intensively-monitored sites, and the potential to improve biogeochemical models by incorporating mechanistic links to the C and S cycles.
Trvalý link: http://hdl.handle.net/11104/0226941