Grassland in northern Tibet plays an important role in the eco-security of the Qinghai-Tibet Plateau and the restoration of deserted and degraded grassland is now a focus for governments. We used remote sensing, simulations and field surveys to analyze the current status, trends and causes of grassland degradation across northern Tibet. We develop several recovery models for degraded grassland based on field experiments in the region. We found that slightly degraded grassland covers 62% and that moderate to severely degraded grassland occupied 15.1% in the Chang Tang Plateau. The amount of degraded alpine steppe increased from 1991, and the amount of area classified as severely degraded increased sharply from 2000. The cause of degraded steppe in northwestern Tibet may be the result of warming and an arid climate; the cause of severe degradation in mid and eastern regions was mainly from overgrazing. Three restoration models are proposed for different levels of degradation: “enclosures” for slightly degraded areas, “enclosures with fertilization” for moderately degraded areas, and “enclosure with oversowing and fertilization” for severely degraded areas.
WANG Jingsheng, ZHANG Xianzhou, CHEN Baoxiong, SHI Peili, ZHANG Junlong, SHEN Zhenxi, TAO Jian, WU Jianshuang
. Causes and Restoration of Degraded Alpine Grassland in Northern Tibet[J]. Journal of Resources and Ecology, 2013
, 4(1)
: 43
-49
.
DOI: 10.5814/j.issn.1674-764x.2013.01.006
Cai X B, Zhang Y Q, Shao W. 2007. Degredation and mechanism of grassland of north Tibet alpine prairie. Soils, 39 (6): 855-858. (in Chinese)
Gao Q Z, Duan M J, Li Y E, et al. 2010. Change trends of grassland coverage and pasture growth in the northwest area of Tibet. Chinese Journal of Agrometeorology, 31(4): 582-585. (in Chinese)
Gao Q Z, Wan Y F, Li Y E, et al. 2007(a). Trends of grassland NPP and its response to human activity in Northern Tibet. Acta Ecologica Sinica, 27(11):4612-4619. (in Chinese)
Gao Q Z, Wan Y F, Li Y E, et al. 2007(b). Grassland net primary productivity and its spatiotemporal distribution in Northern Tibet: A study with CASA model. Chinese Journal of Applied Ecology, 18(11): 2526-2532. (in Chinese)
Gao Q Z, Li Y E, Lin E D, et al. 2005.Temporal and spatial distribution of grassland degradation in Northern Tibet. Acta Geographica Sinica, 60(6):965-973. (in Chinese)
Li H X, Liu S Z. 2007. Monitoring grassland degradation in Naqu County of Tibet. Research of Soil and Water Conservation, 14(2): 98-100. (in Chinese)
Li H X, Liu S Z. 2005. Systematic analysis on the driving force of grassland degradation in north Tibet. Research of Soil and Water Conservation, 12(6): 215-217. (in Chinese)
Mao F, Zhang Y H, Hou Y Y, et al. 2008. Dynam ic assessment of grassland degradation in Naqu of northern Tibet. Chinese Journal of Applied Ecology, 19(2): 278-284. (in Chinese)
Shao W, Cai X B. 2008. Grassland degradation and its formation causes analysis in Tibetan Plateau. Science of Soil and Water Conservation, 6(1): 112-116. (in Chinese)
Sheng W P, Gao Q Z, Li Y E, et al. 2008. Characteristic of Climate Change in Northern Tibet and Its Impact. Plateau Meteorology. 27 (3): 509-516. (in Chinese)
Wang J S, Zhang X Z, Zhao Y P, et al. 2008. Spatio-temporal Pattern of Climate Changes in Northern Tibet’s Qiangtang Plateau. Resources Science, 30(12): 1852-1859. (in Chinese)
Wang J S, Zhang X Z, Zhao Y P, et al. 2010. Spatio-temporal pattern of alpine grassland productivity in Qiangtang Plateau. Chinese Journal of Applied Ecology, 21(6): 1400-1404. (in Chinese)
Tibet Autonomous Land Management Bureau, Tibet Autonomous Animal Husbandry Bureau. 1994. The Grassland Resources of Tibet Autonomous. Beijing: Science Press.
Yang K, Gao Q Z, Li Y E, et al. 2007. Spatial distribution of grassland degradation and trend in Northern Tibet. Advances in Earth Science, 22(4):410-416. (in Chinese)
Yang Y H, Piao S L. 2006. Variations in grassland vegetation cover in relation to climatic factors on the Tibetan Plateau. Journal of Plant Ecology, 30(1): 1-8. (in Chinese)
Zhao Y P, Zhang X Z, Wang J S, Shen Z X. 2009. Correlation analysis between NDVI and climatic factors of grassland ecosystems in the Northern Tibetan Plateau from 1982 to 2003. Resources Science, 31(11): 1988-1998. (in Chinese)
