DOI: 10.1111/gcb.12365
论文题名: Satellite observed widespread decline in Mongolian grasslands largely due to overgrazing
作者: Hilker T. ; Natsagdorj E. ; Waring R.H. ; Lyapustin A. ; Wang Y.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2014
卷: 20, 期: 2 起始页码: 418
结束页码: 428
语种: 英语
英文关键词: Grassland decline
; MAIAC
; MODIS
; Mongolia
; NDVI
; Over-grazing
; Time-series
Scopus关键词: algorithm
; atmospheric correction
; grassland
; land degradation
; MODIS
; NDVI
; overgrazing
; phenology
; remote sensing
; steppe
; time series analysis
; vegetation cover
; Mongolia
; Animalia
; algorithm
; animal
; animal husbandry
; article
; climate
; ecosystem
; environmental protection
; grassland decline
; livestock
; MAIAC
; MODIS
; Mongolia
; NDVI
; over-grazing
; physiology
; population dynamics
; remote sensing
; space flight
; time
; TIME-SERIES
; grassland decline
; MAIAC
; MODIS
; Mongolia
; NDVI
; over-grazing
; time-series
; Algorithms
; Animal Husbandry
; Animals
; Climate
; Conservation of Natural Resources
; Ecosystem
; Livestock
; Mongolia
; Population Dynamics
; Remote Sensing Technology
; Spacecraft
; Time Factors
英文摘要: The Mongolian Steppe is one of the largest remaining grassland ecosystems. Recent studies have reported widespread decline of vegetation across the steppe and about 70% of this ecosystem is now considered degraded. Among the scientific community there has been an active debate about whether the observed degradation is related to climate, or over-grazing, or both. Here, we employ a new atmospheric correction and cloud screening algorithm (MAIAC) to investigate trends in satellite observed vegetation phenology. We relate these trends to changes in climate and domestic animal populations. A series of harmonic functions is fitted to Moderate Resolution Imaging Spectroradiometer (MODIS) observed phenological curves to quantify seasonal and inter-annual changes in vegetation. Our results show a widespread decline (of about 12% on average) in MODIS observed normalized difference vegetation index (NDVI) across the country but particularly in the transition zone between grassland and the Gobi desert, where recent decline was as much as 40% below the 2002 mean NDVI. While we found considerable regional differences in the causes of landscape degradation, about 80% of the decline in NDVI could be attributed to increase in livestock. Changes in precipitation were able to explain about 30% of degradation across the country as a whole but up to 50% in areas with denser vegetation cover (P < 0.05). Temperature changes, while significant, played only a minor role (r2 = 0.10, P < 0.05). Our results suggest that the cumulative effect of overgrazing is a primary contributor to the degradation of the Mongolian steppe and is at least partially responsible for desertification reported in previous studies. © 2013 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62014
Appears in Collections: 影响、适应和脆弱性
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作者单位: College of Forestry, Oregon State University, Corvallis, OR, 97331, United States; National University of Mongolia, Ulaanbatar, Mongolia; NASA Goddard Space Flight Center, 8000 Greenbelt Road, Greenbelt, MD, 20771, United States; Joint Center for Earth System Technology, JCET, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD, 21250, United States
Recommended Citation:
Hilker T.,Natsagdorj E.,Waring R.H.,et al. Satellite observed widespread decline in Mongolian grasslands largely due to overgrazing[J]. Global Change Biology,2014-01-01,20(2)