Accelerating forest loss in Southeast Asian Massif in the 21st century: A case study in Nan Province, Thailand
Accelerating forest loss in Southeast Asian Massif in the 21st century: A case study in Nan Province, Thailand
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DOI：
10.1111/gcb.14366
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发表时间：
2018-07
影响因子：
11.6
通讯作者：
Zhenzhong Zeng;Drew Gower;E. Wood
中科院分区：
文献类型：
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作者：
Zhenzhong Zeng;Drew Gower;E. Wood
世纪，农民正在东南亚地块（SAM）的森林中开辟新的农业边界，引发当地规模的严重环境退化;然而，现有的全球土地利用和森林损失分析忽略了这一边界。本文以位于SAM几何中心的泰国南道省为例，将高分辨率森林覆盖变化产品与细比例尺土地覆盖图相结合，研究了该地区地形对土地利用动态的影响。我们的研究结果显示，2001-2016年期间，南省的森林总损失为66，072公顷（占2000年森林覆盖率的9.1%），到2017年，大部分损失的森林（92%）已转化为作物（主要是玉米）田。每年的森林损失与全球玉米价格显著相关（p < 0.01），再次证实农业扩张是南省森林损失的主要驱动因素。沿着全球玉米价格的上涨，云南省森林损失以每10年2,616 ± 730公顷的速度加速（p < 0.01）。全球玉米价格在2012年达到顶峰，当年的森林损失也达到顶峰（7，523公顷）;自那时以来，森林损失的地点已经转移到海拔较高的陡峭土地。从空间上看，这种小农农业扩张造成的森林损失表现为许多小斑块，即使在中等空间分辨率（如300米）下也无法识别。它解释了现有的全球土地利用/覆盖变化产品如何错过了SAM中广泛和快速的森林损失。它还强调了高分辨率观测的重要性，以评估农业扩张和SAM森林损失的环境影响，包括但不限于对全球碳循环，区域水文和当地环境退化的影响。
Farmers are carving a new agricultural frontier from the forests in the Southeast Asian Massif (SAM) in the 21st century, triggering significant environment degradation at the local scale; however, this frontier has been missed by existing global land use and forest loss analyses. In this paper, we chose Thailand's Nan Province, which is located in the geometric center of SAM, as a case study, and combined high resolution forest cover change product with a fine‐scale land cover map to investigate land use dynamics with respect to topography in this region. Our results show that total forest loss in Nan Province during 2001–2016 was 66,072 ha (9.1% of the forest cover in 2000), and that the majority of this lost forest (92%) had been converted into crop (mainly corn) fields by 2017. Annual forest loss is significantly correlated with global corn price (p < 0.01), re‐confirming agricultural expansion as a key driver of forest loss in Nan Province. Along with the increasing global corn price, forest loss in Nan Province has accelerated at a rate of 2,616 ± 730 ha per decade (p < 0.01). Global corn price peaked in 2012, in which year annual forest loss also reached its peak (7,523 ha); since then, the location of forest loss has moved to steeper land at higher elevations. Spatially, forest loss driven by this smallholder agricultural expansion emerges as many small patches that are not recognizable even at a moderate spatial resolution (e.g. 300 m). It explains how existing global land use/cover change products have missed the widespread and rapid forest loss in SAM. It also highlights the importance of high‐resolution observations to evaluate the environmental impacts of agricultural expansion and forest loss in SAM, including, but not limited to, the impacts on the global carbon cycle, regional hydrology, and local environmental degradation.