Cochrane Mark A, Laurance William F
Geographic Information Science Center of Excellence, South Dakota State University, Brookings, SD 57007, USA.
Ambio. 2008 Dec;37(7-8):522-7. doi: 10.1579/0044-7447-37.7.522.
The Amazon is being rapidly transformed by fire. Logging and forest fragmentation sharply elevate fire incidence by increasing forest desiccation and fuel loads, and forests that have experienced a low-intensity surface fire are vulnerable to far more catastrophic fires. Satellites typically detect thermal signatures from 40 000 to 50 000 separate fires in the Amazon each year, and this number could increase as new highways and infrastructure expand across the basin. Many are concerned that large-scale deforestation, by reducing regional evapotranspiration and creating moisture-trapping smoke plumes, will make the basin increasingly vulnerable to fire. The Amazon may also be affected by future global warming and atmospheric changes, although much remains uncertain. Most models suggest the basin will become warmer throughout this century, although there is no consensus about how precipitation will be affected. The most alarming scenarios project a permanent disruption of the El Niño-Southern Oscillation, leading to greatly increased drought or destructive synergisms between regional and global climate change in the Amazon.
亚马逊地区正迅速受到火灾的影响。伐木和森林碎片化通过加剧森林干燥和燃料负荷，大幅提高了火灾发生率，而经历过低强度地表火灾的森林更容易遭受更具灾难性的火灾。卫星通常每年能探测到亚马逊地区4万至5万起不同的火灾热信号，随着新的公路和基础设施在该流域不断扩展，这一数字可能还会增加。许多人担心，大规模森林砍伐会减少区域蒸散量并产生滞留水分的烟雾羽流，从而使该流域越来越容易发生火灾。亚马逊地区未来可能还会受到全球变暖和大气变化的影响，尽管许多情况仍不确定。大多数模型表明，整个本世纪该流域都会变暖，不过对于降水将如何受到影响尚无共识。最令人担忧的情景预测，厄尔尼诺-南方涛动将永久中断，导致干旱大幅增加，或在亚马逊地区引发区域和全球气候变化之间的破坏性协同效应。
