DOI: 10.1007/s10533-015-0122-3
Scopus记录号: 2-s2.0-84941878723
论文题名: Soil respiration variability across a soil moisture and vegetation community gradient within a snow-scoured alpine meadow
作者: Knowles J.F. ; Blanken P.D. ; Williams M.W.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 125, 期: 2 起始页码: 185
结束页码: 202
语种: 英语
英文关键词: Alpine tundra
; Bidirectional
; Carbon cycle
; Climate change
; Soil moisture
; Soil respiration
Scopus关键词: alpine environment
; carbon cycle
; climate change
; community dynamics
; future prospect
; meadow
; moisture
; soil respiration
; spatiotemporal analysis
; tundra
; vegetation structure
; Colorado
; United States
英文摘要: The alpine tundra landscape is a patchwork of co-mingled ecosystems that vary due to meso-topographical (<100 m) landscape position, shallow subsurface heterogeneity, and subsequent soil moisture availability. This results in hotspots of biological activity, variable carbon cycling over short horizontal distances, and confounds predictions of the alpine tundra response to forecasted environmental change. To advance our understanding of carbon cycling within snow-scoured alpine meadows, we characterized the spatio-temporal variability of soil respiration (RS ) from 17 sites across a broadly representative soil moisture and vegetation gradient, within the footprint of ongoing eddy covariance measurements at Niwot Ridge, Colorado, USA. Chamber-based RS samples were collected on a weekly to bi-weekly basis over three complete growing seasons (2011–2013), and a soil moisture threshold was used to integrate the data into dry, mesic, and wet tundra categories. In every year, measured RS was greatest from mesic tundra, followed by wet and then dry tundra locations. Increasing soil moisture invoked a bidirectional RS response from areas of dry and mesic tundra (directly proportional) compared to wet tundra (inversely proportional), and the optimum RS conditions were between 0.30 and 0.45 m3 m−3 soil moisture, which mainly coincided with soil temperatures below 8 °C. We also developed simple models to predict RS from concurrent measurements of soil moisture and temperature, and from nighttime eddy covariance measurements. Both models were significant predictors of RS in all years and for all ecosystem types (where applicable), but the models did not adequately capture the intra-seasonal RS variability. The median cumulative growing season RS flux ranged from 138.6 g C m−2 in the driest year (2013) to 221.4 g C m−2 in the wettest year (2011), but the cumulative growing season fluxes varied by a factor of five between sites. Our results suggest that increased or more intense precipitation in the future has the potential to increase alpine tundra RS , although this effect will be buffered to some degree by compensatory responses from dry, mesic, and wet alpine tundra. © 2015, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83469
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Geography, University of Colorado, 260 UCB, Boulder, CO, United States; Institute of Arctic and Alpine Research, University of Colorado, 450 UCB, Boulder, CO, United States
Recommended Citation:
Knowles J.F.,Blanken P.D.,Williams M.W.. Soil respiration variability across a soil moisture and vegetation community gradient within a snow-scoured alpine meadow[J]. Biogeochemistry,2015-01-01,125(2)