Warming and earlier spring increase western US forest wildfire activity
Warming and earlier spring increase western US forest wildfire activity
复制标题
DOI：
10.1126/science.1128834
复制
发表时间：
2006-08-18
期刊：
影响因子：
56.9
通讯作者：
Swetnam, T. W.
中科院分区：
文献类型：
--
作者：
Westerling, A. L.;Hidalgo, H. G.;Swetnam, T. W.
人们普遍认为，美国西部森林野火活动在近几十年来有所增加，但无论是最近变化的程度，还是气候可能在多大程度上推动野火的区域变化，都没有系统的记录。许多公众和科学界对美国西部野火变化的讨论都集中在19世纪和20世纪土地使用历史的影响上。我们编制了一个全面的数据库，自1970年以来，在美国西部森林的大型野火，并将其与水文气候和地表数据进行比较。在这里，我们表明，大型野火活动突然增加，显着在20世纪80年代中期，更高的大型野火频率，更长的野火持续时间，更长的野火季节。最大的增加发生在中海拔地区，北方落基山脉的森林，土地利用的历史对火灾风险的影响相对较小，并与春季和夏季温度升高和春季融雪提前密切相关。
Western United States forest wildfire activity is widely thought to have increased in recent decades, yet neither the extent of recent changes nor the degree to which climate may be driving regional changes in wildfire has been systematically documented. Much of the public and scientific discussion of changes in western United States wildfire has focused instead on the effects of 19th- and 20th-century land-use history. We compiled a comprehensive database of large wildfires in western United States forests since 1970 and compared it with hydroclimatic and land-surface data. Here, we show that large wildfire activity increased suddenly and markedly in the mid-1980s, with higher large-wildfire frequency, longer wildfire durations, and longer wildfire seasons. The greatest increases occurred in mid-elevation, Northern Rockies forests, where land-use histories have relatively little effect on fire risks and are strongly associated with increased spring and summer temperatures and an earlier spring snowmelt.