Measuring Woody Encroachment along a Forest-Savanna Boundary in Central Africa
Measuring Woody Encroachment along a Forest-Savanna Boundary in Central Africa
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DOI：
10.1175/2009ei278.1
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发表时间：
2009-01-01
影响因子：
2
通讯作者：
Meir, P.
中科院分区：
文献类型：
--
作者：
Mitchard, E. T. A.;Saatchi, S. S.;Meir, P.
热带森林净面积的变化是几个过程的总和：森林砍伐、先前被砍伐地区的更新以及森林-稀树草原边界空间位置的变化。作者对喀麦隆中部5400公里森林-稀树草原边界地区的植被变化进行了长期（1986-2006年）量化。采用交叉校准归一化植被指数（NDVI）变化检测方法，对1986年、2000年和2006年的三幅高分辨率影像进行了比较。对研究区1000余棵乔木的冠层尺寸和位置进行了测量，发现冠层面积指数（CAI）与NDVI之间存在很强的相关性。在5400 km(2)范围内，12.6%的林冠覆盖度在1986 - 2000年（0.9% yr(-1)）和7.8% （1.29% yr(-1)）表现出显著的正变化
Changes in net area of tropical forest are the sum of several processes: deforestation, regeneration of previously deforested areas, and the changing spatial location of the forest-savanna boundary. The authors conducted a long-term (1986-2006) quantification of vegetation change in a 5400 km(2) forest-savanna boundary area in central Cameroon. A cross-calibrated normalized difference vegetation index (NDVI) change detection method was used to compare three high-resolution images from 1986, 2000, and 2006. The canopy dimensions and locations of over 1000 trees in the study area were measured, and a very strong relationship between canopy area index (CAI) and NDVI was found. Across 5400 km(2) 12.6% of the area showed significant positive change in canopy cover from 1986 to 2000 (0.9% yr(-1)) and 7.8% from 2000 to 2006 (1.29% yr(-1)), whereas