The role of soybean production as an underlying driver of deforestation in the South American Chaco
The role of soybean production as an underlying driver of deforestation in the South American Chaco
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DOI：
10.1016/j.gloenvcha.2017.05.001
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发表时间：
2017-07-01
影响因子：
8.9
通讯作者：
Kuemmerle, Tobias
中科院分区：
文献类型：
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作者：
Fehlenberg, Verena;Baumann, Matthias;Kuemmerle, Tobias
南美洲的热带干燥森林和稀树草原正面临农业扩张带来的越来越大的压力。养牛和大豆生产都是造成森林损失的原因，但它们的相对重要性尚不清楚。同样不清楚的是，其他地方的大豆扩张如何通过将养牛场推向森林砍伐的前沿而影响森林砍伐。为了评估这些问题，我们把重点放在了查科，这是一个1.1亿公顷的生态区，延伸到阿根廷、玻利维亚和巴拉圭，在2000年至2012年期间，大约有800万公顷的森林被砍伐。我们在地区水平上使用面板回归，使用广泛的环境和社会经济控制变量来量化大豆扩张在推动这些森林损失中的作用。我们的模型表明，大豆生产仅是阿根廷查科森林砍伐的直接驱动因素（每公顷森林损失新增0.08公顷大豆面积），而畜牧业与所有三个国家的森林砍伐均显著相关（每公顷森林损失增加0.02头牛）。然而，我们的模型还表明，阿根廷大豆种植可能与玻利维亚和巴拉圭查科的森林砍伐间接相关。此外，我们还发现阿根廷和巴拉圭的大豆扩张（即一年的大豆扩张导致几年后的森林砍伐）与查科森林砍伐之间的关系存在实质性的时滞效应，这进一步表明查科国家内部和国家之间可能存在的迁移效应可能至少部分驱动了森林损失。总的来说，我们的研究表明，查科地区的森林砍伐似乎主要是由全球对大豆的需求激增所驱动的，尽管其他区域性的近似驱动因素有时也很重要。因此，要使查科和其他热带干燥森林的农业生产走上可持续发展的道路，就需要制定政策，考虑到这些规模效应，并考虑到各国内部和各国之间毁林驱动因素的区域差异。
South America's tropical dry forests and savannas are under increasing pressure from agricultural expansion. Cattle ranching and soybean production both drive these forest losses, but their relative importance remains unclear. Also unclear is how soybean expansion elsewhere affects deforestation via pushing cattle ranching to deforestation frontiers. To assess these questions, we focused on the Chaco, a 110 million ha ecoregion extending into Argentina, Bolivia, and Paraguay, with about 8 million ha of deforestation in 2000-2012. We used panel regressions at the district level to quantify the role of soybean expansion in driving these forest losses using a wide range of environmental and socio-economic control variables. Our models suggest that soybean production was a direct driver of deforestation in the Argentine Chaco only (0.08 ha new soybean area per ha forest lost), whereas cattle ranching was significantly associated with deforestation in all three countries (0.02 additional cattle per hectare forest loss). However, our models also suggested Argentine soybean cultivation may indirectly be linked to deforestation in the Bolivian and Paraguayan Chaco. We furthermore found substantial time-delayed effects in the relationship of soybean expansion in Argentina and Paraguay (i.e., soybean expansion in one year resulted in deforestation several years later) and deforestation in the Chaco, further suggesting that possible displacement effects within and between Chaco countries may at least partly drive forest loss. Altogether, our study showed that deforestation in the Chaco appears to be mainly driven by the globally surging demand for soybean, although regionally other proximate drivers are sometimes important. Steering agricultural production in the Chaco and other tropical dry forests onto sustainable pathways will thus require policies that consider these scale effects and that account for the regional variation in deforestation drivers within and across countries.