DOI: 10.1111/gcb.12731
论文题名: Forest ecosystem respiration estimated from eddy covariance and chamber measurements under high turbulence and substantial tree mortality from bark beetles
作者: Speckman H.N. ; Frank J.M. ; Bradford J.B. ; Miles B.L. ; Massman W.J. ; Parton W.J. ; Ryan M.G.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2015
卷: 21, 期: 2 起始页码: 708
结束页码: 721
语种: 英语
英文关键词: Bark beetles
; Chambers
; Disturbance
; EC
; Ecosystem respiration
; filtering
; Respiration modeling
; Soil efflux
; Turbulence
; U
Scopus关键词: beetle
; carbon flux
; eddy covariance
; environmental disturbance
; estimation method
; forest ecosystem
; mortality
; overstory
; respiration
; tree
; turbulence
; Scolytinae
; air
; animal
; circadian rhythm
; comparative study
; environmental protection
; forest
; physiology
; procedures
; season
; tree
; United States
; weevil
; Air Movements
; Animals
; Circadian Rhythm
; Conservation of Natural Resources
; Forests
; Seasons
; Trees
; Weevils
; Wyoming
英文摘要: Eddy covariance nighttime fluxes are uncertain due to potential measurement biases. Many studies report eddy covariance nighttime flux lower than flux from extrapolated chamber measurements, despite corrections for low turbulence. We compared eddy covariance and chamber estimates of ecosystem respiration at the GLEES Ameriflux site over seven growing seasons under high turbulence [summer night mean friction velocity (u*) = 0.7 m s-1], during which bark beetles killed or infested 85% of the aboveground respiring biomass. Chamber-based estimates of ecosystem respiration during the growth season, developed from foliage, wood, and soil CO2 efflux measurements, declined 35% after 85% of the forest basal area had been killed or impaired by bark beetles (from 7.1 ± 0.22 μmol m-2 s-1 in 2005 to 4.6 ± 0.16 μmol m-2 s-1 in 2011). Soil efflux remained at ~3.3 μmol m-2 s-1 throughout the mortality, while the loss of live wood and foliage and their respiration drove the decline of the chamber estimate. Eddy covariance estimates of fluxes at night remained constant over the same period, ~3.0 μmol m-2 s-1 for both 2005 (intact forest) and 2011 (85% basal area killed or impaired). Eddy covariance fluxes were lower than chamber estimates of ecosystem respiration (60% lower in 2005, and 32% in 2011), but the mean night estimates from the two techniques were correlated within a year (r2 from 0.18 to 0.60). The difference between the two techniques was not the result of inadequate turbulence, because the results were robust to a u* filter of >0.7 m s-1. The decline in the average seasonal difference between the two techniques was strongly correlated with overstory leaf area (r2 = 0.92). The discrepancy between methods of respiration estimation should be resolved to have confidence in ecosystem carbon flux estimates. © 2014 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61838
Appears in Collections: 影响、适应和脆弱性
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作者单位: Natural Resource Ecology Laboratory and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, United States; Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY, United States; Rocky Mountain Research Station, U.S. Forest Service, Fort Collins, CO, United States; U.S. Geological Survey, Southwest Biological Science Center, Flagstaff, AZ, United States; Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, CO, United States
Recommended Citation:
Speckman H.N.,Frank J.M.,Bradford J.B.,et al. Forest ecosystem respiration estimated from eddy covariance and chamber measurements under high turbulence and substantial tree mortality from bark beetles[J]. Global Change Biology,2015-01-01,21(2)