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Titolo:
Response of CO2 and CH4 emissions from peatlands to warming and water table manipulation
Autore:
Updegraff, K; Bridgham, SD; Pastor, J; Weishampel, P; Harth, C;
Indirizzi:
Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA Univ Minnesota St Paul MN USA 55108 rest Resources, St Paul, MN 55108 USA Univ Notre Dame, Dept Biol Sci, Notre Dame, IN 46556 USA Univ Notre Dame Notre Dame IN USA 46556 iol Sci, Notre Dame, IN 46556 USA Univ Minnesota, Nat Resources Res Inst, Duluth, MN 55811 USA Univ Minnesota Duluth MN USA 55811 sources Res Inst, Duluth, MN 55811 USA Cornell Univ, Dept Nat Resources, Ithaca, NY 14850 USA Cornell Univ Ithaca NY USA 14850 Dept Nat Resources, Ithaca, NY 14850 USA
Titolo Testata:
ECOLOGICAL APPLICATIONS
fascicolo: 2, volume: 11, anno: 2001,
pagine: 311 - 326
SICI:
1051-0761(200104)11:2<311:ROCACE>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
SWEDISH RAISED BOG; METHANE EMISSIONS; CARBON BALANCE; NORTHERN WETLANDS; NITROUS-OXIDE; FOREST SOILS; SPHAGNUM; GROWTH; OXIDATION; AMMONIUM;
Keywords:
C dynamics; CH4; climate change; CO2; dissolved N; Minnesota; USA; net primary productivity; peatlands; soil respiration; soil temperature; water table; wetlands;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
62
Recensione:
Indirizzi per estratti:
Indirizzo: Updegraff, K Univ Minnesota, Dept Forest Resources, St Paul, MN 55108 USA Univ Minnesota St Paul MN USA 55108 s, St Paul, MN 55108 USA
Citazione:
K. Updegraff et al., "Response of CO2 and CH4 emissions from peatlands to warming and water table manipulation", ECOL APPL, 11(2), 2001, pp. 311-326

Abstract

Projected changes in climate could shift northern peatlands from their current status as net C sinks toward that of being net C sources by changing soil temperatures and hydrology. We assessed the importance of water table and soil temperature as controls over ecosystem respiration in a bog and sedge fen in northern Minnesota, USA, by means of a manipulative mesocosm experiment. Fifty-four intact monoliths were removed from a bog and a fen and installed in insulated tanks that permitted control of the water table and were heated by overhead infrared heaters. The experimental design was a fully crossed factorial combination of two communities, three water tables, andthree heat levels. Fcosystem respiration as indicated by emission of CO2 and CH4, dissolved nutrient fluxes, and productivity were measured and summarized for each growing season from 1995 to 1997. Seasonal ecosystem respiration (ER) as indicated by CO2 emissions responded almost exclusively to soil temperature and did not differ between community types (similar to 630 g C/ m(2)) or with water table level. These results suggest that community type, within certain limits, will not be an important factor in predicting temperature-driven increases in ER. The response of CH4 flux to soil temperature and water table setting became progressively stronger in each succeeding growing season. Seasonal CH4 emissions were on average three times higher in the bog than in the fen mesocosms (21 vs. 7 g C/m(2)). Aboveground net primary productivity and dissolved N retention were also higher in the bog mesocosms. There were strong correlations between CH4 flux and N retention, but generally weak correlations between CH4 and plant primary production. The relatively lower CH4 emissions from the fen mesocosms appear to result mainly from higher rates of methanotrophy in the aerated zone, possibly reinforced by the effects of higher porewater N concentrations and lower primary productivity compared to the bogs. The results confirm the existence of strong environmental controls over ERand methanogenesis, which are modulated by complex interactions between plant community and soil nutrient dynamics. The differential responses of these ecosystem functions to climate change may complicate efforts to predict future changes in C dynamics in these important repositories of soil C.

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Documento generato il 20/09/20 alle ore 07:27:09