Historic climate-fire-vegetation interactions of the West versus East Kootenays: Implications of climate change and fire suppression

我们的研究比较了东库特奈区克兰布鲁克附近的Joseph-Gold Creek分水岭和不列颠哥伦比亚省东南部西库特奈区Nelson附近西ARM省级公园的Five Mile-Lasca Creek分水岭。理论上的火灾-植被模型表明，这两个地区历史上的火灾状况有很大不同。我们的研究验证了这样的假设，即人类土地利用、灭火和气候变化的综合影响使这两个地点的火灾状况趋于均匀。目前，这两个地点发生严重火灾的风险很高，主要是因为东库特奈研究区较干燥的森林没有发生火灾，而西库特奈研究区较干旱的森林越来越频繁地发生干旱。我们将使用多代理古生态方法来检查和比较不列颠哥伦比亚省东南部库特奈区和西库特奈区两个地点在一系列时间尺度上的气候、植被和火灾的历史。对湖泊沉积物的古生态研究将量化1000年至10000年期间火灾制度和森林组成的变化。树木生态(树轮)分析将通过以下方式探讨这些变化发生的机制：(A)重建过去300至500年的气候，(B)通过分析火灾伤疤来量化历史火灾频率，以及(C)调查年际至年代际气候变化对火灾制度的影响。

Our research compares the Joseph-Gold Creek watersheds near Cranbrook in the East Kootenay district and the Five Mile-Lasca Creek watersheds in West Arm Provincial Park near Nelson in the West Kootenay district of southeastern British Columbia. Theoretical fire-vegetation models suggest the historic fire regimes differed considerably in the two districts. Our study tests the hypothesis that the combined effects of human land use, fire suppression and climate variation have homogenized the fire regimes in the two locations. Risk of severe fires is presently high in both locations, primarily due to fire exclusion in the drier forests of the East Kootenay study area and increasingly frequent droughts in the more mesic forests of the West Kootenay study area. We will use a multi-proxy paleoecological approach to examine and compare the history of climate, vegetation and fire at a range of temporal scales at two locations in the West and East Kootenay districts of southeastern British Columbia. Paleoecological studies of lake sediments will quantify changes in fire regimes and forest composition over periods of 1000 to 10,000 years. Dendroecological (tree-ring) analyses will address the mechanisms by which these changes occur by (a) reconstructing climate over the last 300 to 500 years, (b) quantifying historic fire frequency through analysis of fire scars, and (c) investigating the impacts of inter-annual to decadal climate variation on fire regimes.