Environmental influences on carbon dioxide fluxes over three grassland ecosystems in China

NWIPB OpenIR

	Environmental influences on carbon dioxide fluxes over three grassland ecosystems in China
	Fu, Y.1; Zheng, Z.1,2; Yu, G.1; Hu, Z.1; Sun, X.1; Shi, P.1; Wang, Y.3; Zhao, X.4
	2009
发表期刊	BIOGEOSCIENCES
ISSN	1726-4170
卷号	6 期号:12 页码:2879-2893
文章类型	Article
摘要	This study compared carbon dioxide (CO(2)) fluxes over three grassland ecosystems in China, including a temperate semiarid steppe in Inner Mongolia (NMG), an alpine shrub-meadow in Qinghai (HB), and an alpine meadow-steppe in Tibet (DX). Measurements were made in 2004 and 2005 using the eddy covariance technique. Objectives were to document the seasonality of the net ecosystem exchange of CO(2) (NEE) and its components, gross ecosystem photosynthesis (GEP), and ecosystem respiration (R(eco)), and to examine how environmental factors affect the CO(2) exchange in these grassland ecosystems. The 2005 growing season (from May to September) was warmer than that of 2004 across the three sites, and precipitation in 2005 was less than that in 2004 at NMG and DX. The magnitude of CO(2) fluxes (daily and annual sums) was largest at HB, which also showed the highest temperature sensitivity of R(eco) among the three sites. A stepwise multiple regression analysis showed that the seasonal variation of GEP, R(eco), and NEE of the alpine shrub-meadow was mainly controlled by air temperature, whereas leaf area index can likely explain the seasonal variation in GEP, R(eco), and NEE of the temperate steppe. The CO(2) fluxes of the alpine meadow-steppe were jointly affected by soil moisture and air temperature. The alpine shrub-meadow acted as a net carbon sink over the two study years, whereas the temperate steppe and alpine meadow-steppe acted as net carbon sources. Both GEP and R(eco) were reduced by the summer and spring drought in 2005 at NMG and DX, respectively. The accumulated leaf area index during the growing season (LAI(sum)) played a key role in the interannual and intersite variation of annual GEP and R(eco) across the study sites and years, whereas soil moisture contributed most significantly to the variation in annual NEE. Because LAI(sum) was significantly correlated with soil moisture at a depth of 20 cm, we concluded that the available soil moisture other than annual precipitation was the most important factor controlling the variation in the CO(2) budgets of different grassland ecosystems in China.; This study compared carbon dioxide (CO(2)) fluxes over three grassland ecosystems in China, including a temperate semiarid steppe in Inner Mongolia (NMG), an alpine shrub-meadow in Qinghai (HB), and an alpine meadow-steppe in Tibet (DX). Measurements were made in 2004 and 2005 using the eddy covariance technique. Objectives were to document the seasonality of the net ecosystem exchange of CO(2) (NEE) and its components, gross ecosystem photosynthesis (GEP), and ecosystem respiration (R(eco)), and to examine how environmental factors affect the CO(2) exchange in these grassland ecosystems. The 2005 growing season (from May to September) was warmer than that of 2004 across the three sites, and precipitation in 2005 was less than that in 2004 at NMG and DX. The magnitude of CO(2) fluxes (daily and annual sums) was largest at HB, which also showed the highest temperature sensitivity of R(eco) among the three sites. A stepwise multiple regression analysis showed that the seasonal variation of GEP, R(eco), and NEE of the alpine shrub-meadow was mainly controlled by air temperature, whereas leaf area index can likely explain the seasonal variation in GEP, R(eco), and NEE of the temperate steppe. The CO(2) fluxes of the alpine meadow-steppe were jointly affected by soil moisture and air temperature. The alpine shrub-meadow acted as a net carbon sink over the two study years, whereas the temperate steppe and alpine meadow-steppe acted as net carbon sources. Both GEP and R(eco) were reduced by the summer and spring drought in 2005 at NMG and DX, respectively. The accumulated leaf area index during the growing season (LAI(sum)) played a key role in the interannual and intersite variation of annual GEP and R(eco) across the study sites and years, whereas soil moisture contributed most significantly to the variation in annual NEE. Because LAI(sum) was significantly correlated with soil moisture at a depth of 20 cm, we concluded that the available soil moisture other than annual precipitation was the most important factor controlling the variation in the CO(2) budgets of different grassland ecosystems in China.
WOS标题词	Science & Technology ; Life Sciences & Biomedicine ; Physical Sciences
关键词[WOS]	QINGHAI-TIBETAN PLATEAU ; NORTHERN TEMPERATE GRASSLAND ; LEYMUS-CHINENSIS STEPPE ; WATER-VAPOR EXCHANGE ; CO2 EXCHANGE ; INTERANNUAL VARIATION ; EDDY COVARIANCE ; INNER-MONGOLIA ; ALPINE MEADOW ; LONG-TERM
收录类别	SCI
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Geology
WOS类目	Ecology ; Geosciences, Multidisciplinary
WOS记录号	WOS:000273060100010
引用统计	被引频次：106[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/1910
专题	中国科学院西北高原生物研究所
作者单位	1.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China 2.E China Normal Univ, Shanghai 200062, Peoples R China 3.Chinese Acad Sci, Grad Univ, Beijing 100039, Peoples R China 4.Chinese Acad Sci, NW Plateau Inst Biol, Xining 810001, Peoples R China
推荐引用方式 GB/T 7714	Fu, Y.,Zheng, Z.,Yu, G.,et al. Environmental influences on carbon dioxide fluxes over three grassland ecosystems in China[J]. BIOGEOSCIENCES,2009,6(12):2879-2893.
APA	Fu, Y..,Zheng, Z..,Yu, G..,Hu, Z..,Sun, X..,...&Zhao, X..(2009).Environmental influences on carbon dioxide fluxes over three grassland ecosystems in China.BIOGEOSCIENCES,6(12),2879-2893.
MLA	Fu, Y.,et al."Environmental influences on carbon dioxide fluxes over three grassland ecosystems in China".BIOGEOSCIENCES 6.12(2009):2879-2893.