近日，美国哥伦比亚大学
研究组提出了一个由这种气流产生的时空相互作用模型，以估计局部扰动沿大气轨迹向下风位置的影响。空间分量捕获由邻近区域传播的级联效应，而时间分量捕获局部扰动的持久性。重要的是，所有这些网络效应都可以用一个矩阵来描述，作为一个空间乘数，放大当地的森林干扰。这个矩阵对决策者具有实际意义，因为他们可以很容易地绘制出最初森林扰动的损害被放大和传播到哪里。
该课题组人员确定了整个盆地可能受到最大影响的地区，以及那些最容易受到偏远森林砍伐引发的冲击的地区。平均而言，亚马逊地区由风介导的级联效应的存在使初始损害的影响增加了一倍。
然而，这种影响存在异质性。虽然某些区域的伤害不会传播，但在其他区域，伤害可以扩大250%。由于研究团队只考虑了风介导的溢出效应，它们的乘数2应被视为下限。
据悉，亚马逊雨林正经历着前所未有的人为干扰。除了局部影响外，这种变化很可能随着信风产生的东西向大气流动而层叠发生。
附：英文原文
Title: Estimating the spatial amplification of damage caused by degradation in the Amazon
Author: Araujo, Rafael, Assuno, Juliano, Hirota, Marina, Scheinkman, José A.
Issue&Volume: 2023-11-7
Abstract: The Amazon rainforests have been undergoing unprecedented levels of human-induced disturbances. In addition to local impacts, such changes are likely to cascade following the eastern–western atmospheric flow generated by trade winds. We propose a model of spatial and temporal interactions created by this flow to estimate the spread of effects from local disturbances to downwind locations along atmospheric trajectories. The spatial component captures cascading effects propagated by neighboring regions, while the temporal component captures the persistence of local disturbances. Importantly, all these network effects can be described by a single matrix, acting as a spatial multiplier that amplifies local forest disturbances. This matrix holds practical implications for policymakers as they can use it to easily map where the damage of an initial forest disturbance is amplified and propagated to. We identify regions that are likely to cause the largest impact throughout the basin and those that are the most vulnerable to shocks caused by remote deforestation. On average, the presence of cascading effects mediated by winds in the Amazon doubles the impact of an initial damage. However, there is heterogeneity in this impact. While damage in some regions does not propagate, in others, amplification can reach 250%. Since we only account for spillovers mediated by winds, our multiplier of 2 should be seen as a lower bound.
DOI: 10.1073/pnas.2312451120
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2312451120