DOI: 10.1002/2017JG004255
Scopus记录号: 2-s2.0-85042232616
论文题名: Renewed Estimates of Grassland Aboveground Biomass Showing Drought Impacts
作者: Li F. ; Chen J.Q. ; Zeng Y. ; Wu B.F. ; Zhang X.Q.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 1 起始页码: 138
结束页码: 148
语种: 英语
英文关键词: aboveground biomass
; drought
; Inner Mongolia grasslands
; livestock
; PDSI
; remote sensing model
Scopus关键词: aboveground biomass
; biome
; concentration (composition)
; drought
; ecosystem structure
; grassland
; growing season
; livestock
; remote sensing
; vegetation index
; China
; Nei Monggol
英文摘要: Variations in ecosystem composition and structure within a cover type of the same biome can be responsible for the large amounts of uncertainty in remote sensing modeling of aboveground biomass (AGB). Based on 820 ground measurements of AGB and the pure vegetation index models, we proposed a spatially variable remote sensing scalar (i.e., M scalar) in estimating AGB by addressing within-type variations of vegetation. We tested this new modeling approach in Inner Mongolia grasslands and achieved a higher R2 (>0.88) and lower RMSE value (<28.17 g/m2) than those in the conventional remote sensing models. The annual average (STD) of the grassland AGB for 2001–2016 was ~87 (±9) Tg, with an AGB density of 104 ± 74 g/m2. The interannual variation of AGB appeared insignificant over the study period, except in the western region where it increased significantly. The dynamics of AGB were highly correlated with drought severity during the growing season (R2 = 0.691, P < 0.001). AGB under normal climate (i.e., without drought) was ~90.88 Tg, but it increased by ~19% (17.11 Tg) in a wet year (2012) and decreased by 20% (18.16 Tg) in a dry year (2001). More importantly, the high grazing intensity played a less significant role in directing grassland AGB dynamics (R2 = 0.024, P = 0.599). Future efforts are needed to explore how within-type variation of vegetation may change temporally and spatially in accurate estimate of AGB across heterogeneous landscapes, as well as the potential underlying mechanisms from biological, physical, and human perspectives. ©2017. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114735
Appears in Collections: 气候减缓与适应
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作者单位: Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, United States; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China; Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China; Department of Earth and Environmental Sciences, Nagoya University, Nagoya, Japan
Recommended Citation:
Li F.,Chen J.Q.,Zeng Y.,et al. Renewed Estimates of Grassland Aboveground Biomass Showing Drought Impacts[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(1)