南京林业大学学报(自然科学版) ›› 2019, Vol. 62 ›› Issue (02): 184-190.doi: 10.3969/j.issn.1000-2006.201805001

• 研究简报 • 上一篇    下一篇

基于时间序列MODIS-VCF数据的云南省森林覆盖变化及破碎化分析

朱若柠1,沈文娟1,张亚丽1,李明诗1,2*   

  1. (1. 南京林业大学林学院,江苏 南京 210037; 2. 南京林业大学,南方现代林业协同创新中心,江苏 南京 210037)
  • 出版日期:2019-03-30 发布日期:2019-03-30
  • 基金资助:
    收稿日期:2018-05-01 修回日期:2018-09-06
    基金项目:国家自然科学基金项目(31670552); 江苏省“青蓝工程”项目; 江苏高校品牌专业建设工程资助项目(PPZY2015A062)。
    第一作者:朱若柠(526089620@qq.com)。
    *通信作者:李明诗(nfulms@njfu.edu.cn),教授,博士,ORCID(0000-0001-5689-5091)。

Assessing changes in forest coverage and forest fragmentation patterns in Yunnan Province from time series MODIS-VCF products(2000-2016)

ZHU Ruoning1, SHEN Wenjuan1, ZHANG Yali1, LI Mingshi1,2*   

  1. (1.College of Forestry, Nanjing Forestry University,Nanjing 210037,China; 2.Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037,China)
  • Online:2019-03-30 Published:2019-03-30

摘要: 【目的】分析云南省2000—2016年森林分布及森林破碎化模式,评估现行森林经营政策的有效性,总结有关森林经营政策执行的经验和教训。【方法】以250 m分辨率MODIS-VCF(vegetation continuous fields, 植被连续场)产品及其衍生数据为基础数据源,利用单一像元位置上森林覆盖随时间的变化而拟合趋势线,通过对斜率、截距及该像元位置上森林覆盖率的方差进行阈值化操作,判定该像元上森林变化类型。在此基础上,利用3×3移动窗口分析技术提取窗口内森林面密度及森林连接度指数,并借助渗透理论将窗口中心森林像元归并为内部、孔洞、边缘、斑块、过渡或未确定等破碎化类型之一。最后,将典型区域的生物多样性动态与森林破碎化成分进行了关联性分析。【结果】2000—2016年,云南省森林面积呈波动增加态势,其中森林持续覆盖增加的区域占云南省总面积的比例约为30.57%。高覆盖变化主要分布在云南省西部和南部,低覆盖变化分布在北部、东部和中部。分析研究期内森林破碎化成分的占比发现:内部森林所占面积比例由2000年的50.03%增长到2006年的57.32%, 再略降到2011年的56.33%,最后升到2016年的63.32%; 孔洞森林面积占比则由29.41%下降到2006年的27.81%,2011年小幅升至28.36%, 再降到2016年的24.54%。边缘森林、斑块森林、过渡森林也与孔洞森林的变化趋势一致,基本上呈现逐渐下降的态势。【结论】在退耕还林、集体林权制度改革等政策推动下,云南省森林面积整体增加,森林破碎化程度降低。2006—2011年森林覆盖略微减少,热点地区森林破碎化程度增加,这同时影响到区域野生动物的数量下降和分布趋于紧缩。

Abstract: 【Objective】The main objective of this study was to assess the effectiveness of existing forest management policies implemented in Yunnan Province, and to learn or summarize experiences regarding the implementation of forest-related strategies by analyzing the changes in the spatio-temporal patterns of forest coverage and fragmentation in Yunnnan Province during 2000-2006.【Method】Using MODIS-vegetation continuous fields(VCF)product and its derivatives as the basic data source, with a spatial resolution of 250 m, a linear equation was fitted for each pixel on the basis of its variations in forest coverage rate against the time duration of 2000 to 2016. By exploring the slope and intercept of the fitted equation as well as the variance in forest coverage at that particular pixel, empirical thresholds were modified to classify this pixel into four types of forest coverage change, and a 3 × 3 moving window analysis technique was used to extract two indices within the window: forest area density and forest connectivity. Based on these two measures, in conjunction with the percolation theory, the central forest pixel within the window was classified into one of the six fragmentation components, namely, interior, perforation, edge, patch, transitional and undetermined. Finally, interconnections between forest fragmentation and biodiversity dynamics in the typical areas of Yunnan Province were qualitatively depicted. 【Result】During 2000-2016, the forest area in Yunnan Province tended to unstably increase, and the area of the forest coverage constant increasing type accounted for 30.57% of the total territory of Yunnan Province. In addition, the high forest coverage change type was principally distributed in southern and western Yunnan, and the low forest coverage change type was mainly concentrated in central, northern and eastern Yunnan. During the study period, the areal share of the interior forest increased from 50.03% in 2000 to 57.32% in 2006, with a slight decrease to 56.33% in 2011 and increase to 63.32% in 2016; however, the areal share of the perforation forest decreased from 29.41% in 2000 to 27.81% in 2006, with a slight increase to 28.36% in 2011 and decrease to 24.54% in 2016. Simultaneously, other components, including edge, patch and transitional fragmentation elements, showed a change trend similar to perforation, suggesting decelerated forest fragmentation in Yunnan Province during the period. 【Conclusion】Driven by various forestry policies, such as returning cropland to forest and reformation of collective forest tenures, the forest area in Yunnan Province, overall, tends to increase gradually, and the forest fragmentation level appears to have decelerated. However, across 2006 and 2011, a slight decrease in forest coverage, accompanied by increased forest fragmentation, was observed in Yunnan, which is consistent with a decrease in wildlife quantity and a more compact distribution of wildlife in some typical regions. These findings provide a valuable reference for forest management decisions and conservation biology studies.

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