Effects of historical changes in climate on carbon storage in Alaskan arctic tundra

Conference · Wed Jun 01 00:00:00 EDT 1994 · Bulletin of the Ecological Society of America; (United States)

OSTI ID:7017576

McKane, R; Rastetter, E; Shaver, G; Nadelhoffer, K; Giblin, A; Laundre, J ^[1]; Chapin, III, F S ^[2]

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1. Marine Biological Laboratory, Woods Hole, MA (United States)
2. Univ. of California, Berkeley, CA (United States)

Surface air temperature in Arctic regions has increased since pre-industrial times, raising concerns that warmer and drier conditions have increased soil decomposition rates, thereby stimulating the release to the atmosphere of the large stores of C in arctic soils. We used a model (MBL-GEM) of ecosystem C and N dynamics to predict and analyze historical (1829 to 1990) changes in C storage in a tussock tundra ecosystem in Alaska. We calibrated the model by deriving a single parameter set that closely simulated responses to decade-long manipulations of nutrients, temperature, light, and atmospheric CO[sub 2]. Based on the combined effects of reconstructed historical changes in atmospheric CO[sub 2], mean growing-season temperature and two alternative soil moisture scenarios, the model predicts a [minus]3.0 + 2.1 percent change in ecosystem C from 1829 to 1990. These results are consistent with field evidence that historically recent changes in C storage of tussock tundra have been relatively small. However, the model also predicts that relatively large transient losses of ecosystem C(50 to 120 g m[sup [minus]2]yr[sup [minus]1]) may frequently have occurred since the late 1800s, with one of the largest simulated C losses of the 20th century occurring from 1988 to 1990 (85, 92, 61 g C m[sup [minus]2]yr[sup [minus]1], respectively). These simulated losses were at the low end of the range of losses measured in Alaskan tussock tundra from 1983 to 1990 (65 to 487 g C m[sup [minus]2]yr[sup [minus]1]), but nonetheless suggest that these recent losses may be transitory in nature.

• OSTI ID: 7017576
• Report Number(s): CONF-940894-; CODEN: BECLAG
• Journal Information: Bulletin of the Ecological Society of America; (United States), Vol. 75:2; Conference: Annual Ecological Society of America (ESA) meeting: science and public policy, Knoxville, TN (United States), 7-11 Aug 1994; ISSN 0012-9623
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ALASKA
TUNDRA
CARBON
ECOLOGICAL CONCENTRATION
CARBON DIOXIDE
ENVIRONMENTAL EFFECTS
SOIL CHEMISTRY
ANNUAL VARIATIONS
CLIMATIC CHANGE
MATHEMATICAL MODELS
SOILS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
DEVELOPED COUNTRIES
ELEMENTS
NONMETALS
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
USA
VARIATIONS
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)