Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

	Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed
	Yan, JZ ; Zhang, YL ; Bai, WQ ; Liu, YH ; Bao, WK ; Liu, LS ; Zheng, D
刊名	SCIENCE IN CHINA SERIES D-EARTH SCIENCES
	2005
卷号	48 期号:12 页码:2214_2230
关键词	land use/cover classification upper Dadu River watershed vegetation successions GIS RS
ISSN号	1006-9313
通讯作者	Zhang, YL, Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Beijing 100101, Peoples R China.
中文摘要	To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation successions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2000 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, environmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, alpine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2000, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43%. Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2000, only 6.86 percents of logged areas were converted to shrubs, meadows or croplands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sabina tibetica forests and meadows. The and valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and reconstruction. Field investigations have found that the current measures have not concerned with how to keep the livelihood of local farmers and herders. The most important measure for ecological protection and restoration is to help the farmers and herders to raise the living standard, which means that they will never need to rely only on the colonizing of croplands, the logging of forests and the grazing of livestock to make a living.
学科主题	Geosciences, Multidisciplinary
收录类别	SCI
语种	英语
公开日期	2011-07-08
内容类型	期刊论文
源URL	[http://210.75.237.14/handle/351003/21762]
专题	成都生物研究所_生态研究
推荐引用方式 GB/T 7714	Yan, JZ,Zhang, YL,Bai, WQ,et al. Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed[J]. SCIENCE IN CHINA SERIES D-EARTH SCIENCES,2005,48(12):2214_2230.
APA	Yan, JZ.,Zhang, YL.,Bai, WQ.,Liu, YH.,Bao, WK.,...&Zheng, D.(2005).Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed.SCIENCE IN CHINA SERIES D-EARTH SCIENCES,48(12),2214_2230.
MLA	Yan, JZ,et al."Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed".SCIENCE IN CHINA SERIES D-EARTH SCIENCES 48.12(2005):2214_2230.