Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Station Sainte-Foy, Quebec, Quebec G1V 4C7, Canada.
Ecol Appl. 2013 Jun;23(4):904-23. doi: 10.1890/12-0698.1.
Fire is a major disturbance in Canadian forests. Along with fuel and ignition characteristics, climatic conditions are seen as one of the main drivers of fire regimes. Projected changes in climate are expected to significantly influence fire regimes in Canada. As fire regime greatly shapes large-scale patterns in biodiversity, carbon, and vegetation, as well as forest and fire management strategies, it becomes necessary to define regions where current and future fire regimes are homogeneous. Random Forests (RF) modeling was used to relate fire regime attributes prevailing between 1961 and 1990 in eastern Canada with climatic/fire-weather and environmental variables. Using climatic normals outputs from the Canadian Regional Climate Model (CRCM), we delineated current (1961-1990) and future (2011-2040, 2040-2070, 2071 2100) homogeneous fire regime (HFR) zones. Heterogeneous response of fire regime to climate changes is projected for eastern Canada with some areas (e.g., western Quebec) experiencing very small alterations while others (e.g., southeastern Ontario) are facing great shifts. Overall, models predicted a 2.2- and 2.4-fold increase in the number of fires and the annual area burned respectively mostly as a result of an increase in extreme fire-weather normals and mean drought code. As extreme fire danger would occur later in the fire season on average, the fire season would shift slightly later (5-20 days) in the summer for much of the study area while remaining relatively stable elsewhere. Although fire regime values would change significantly over time, most zone boundaries would remain relatively stable. The information resulting from HFR zonations is clearly of interest for forest and fire management agencies as it reveals zones with peculiar fire regimes that would have been hidden otherwise using predefined administrative or ecological stratifications.
火灾是加拿大森林的主要干扰因素。除燃料和点火特征外，气候条件被视为火灾发生规律的主要驱动因素之一。预计气候变化将显著影响加拿大的火灾发生规律。由于火灾发生规律极大地影响了生物多样性、碳和植被的大规模格局，以及森林和火灾管理策略，因此有必要定义当前和未来火灾发生规律具有同质性的区域。随机森林（RF）模型被用于将加拿大东部 1961 年至 1990 年期间普遍存在的火灾发生规律属性与气候/火灾天气和环境变量联系起来。我们使用加拿大区域气候模型（CRCM）的气候正常值输出，划定了当前（1961-1990 年）和未来（2011-2040 年、2040-2070 年、2071-2100 年）同质火灾发生规律（HFR）区。预计加拿大东部地区的火灾发生规律对气候变化的响应存在异质性，一些地区（例如，魁北克西部）的变化很小，而另一些地区（例如，安大略东南部）则面临巨大的变化。总体而言，模型预测火灾数量将增加 2.2 倍，每年燃烧面积将增加 2.4 倍，这主要是由于极端火灾天气正常值和平均干旱代码的增加所致。由于极端火灾危险平均会在火灾季节后期发生，因此夏季大部分研究区域的火灾季节将略微推迟（5-20 天），而其他地区则相对稳定。尽管火灾发生规律值会随时间发生显著变化，但大多数区域边界仍将相对稳定。同质火灾发生规律分区产生的信息显然对森林和火灾管理机构具有重要意义，因为它揭示了具有特殊火灾发生规律的区域，如果使用预定义的行政或生态分层，这些区域将无法被发现。
