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变暖和早春增加了美国西部森林野火活动
A L Westerling1, H G Hidalgo, D R Cayan
1Scripps Institution of Oceanography, La Jolla, CA 92093, USA. awesterling@ucmerced.edu
概括
自20世纪80年代中期以来,美国西部森林的野火活动显著增加. 这一激增与气候变化有关,包括气温升高和较早融雪,特别是在北方的洛基山脉.
科学领域:
- 生态生态学 生态生态学
- 气候科学 气候科学
- 林业 林业 林业 林业 林业
背景情况:
- 据认为,美国西部森林野火活动最近有所增加.
- 以前的讨论经常强调19世纪和20世纪土地利用历史对野火的影响.
- 缺乏对最近野火变化和气候驱动因素的系统文档.
研究的目的:
- 自1970年以来,系统地记录美国西部野火活动的变化.
- 调查气候变化对区域野火模式的影响程度.
- 为了比较气候与土地利用历史对近期野火趋势的影响.
主要方法:
- 编制了从1970年起美国西部森林的大型野火的综合数据库.
- 将野火数据与水气候和陆地表面数据进行比较.
- 分析了野火频率,持续时间和季节性的趋势.
主要成果:
- 大型野火活动在20世纪80年代中期突然显著增加.
- 观察到野火频率,持续时间和季节长度的增加.
- 北方洛基山脉中层森林的最大增长,与更高的温度和更早的融雪有着强烈的关联.
结论:
- 气候变化,特别是气温上升和早雪融化,是美国西部森林野火活动增加的重要驱动因素.
- 土地使用历史对某些地区如北方洛基山脉当前的火灾风险的影响相对较小.
- 这些发现强调了气候在当代野火动态中的关键作用.
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