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，这两个地区发生严重火灾的风险都很高，这主要是由于东库特奈研究区较干燥的森林被排除在火势之外，以及西库特奈研究区较中等森林的干旱日益频繁。*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地区两个地点在时间尺度上的气候、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(A)重建过去300到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)调查年际到年代际气候变化对火灾制度的影响，来研究这些变化发生的机制。最终，我们的目标是(A)量化火灾频率和严重程度在空间和时间上的自然变化范围，(B)在不同气候变化情景的影响下预测未来的火灾制度，以及(C)在气候变化和改变的干扰制度的影响下预测未来的主要植被。我们将与不列颠哥伦比亚省森林和牧场部、不列颠哥伦比亚省公园和环境部、纳尔逊市和克兰布鲁克市以及Tembec等当地森林管理公司的代表合作，确定因人类土地利用和灭火而显著改变的景观部分，需要生态恢复和/或缓解，以保护经济和文化资源。

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.Ultimately, we aim to (a) quantify the natural range of variability in fire frequency and severity, both spatially and temporally, (b) predict future fire regimes under the influence of different scenarios of climate change, and (c) predict future dominant vegetation under the influence of climate change and altered disturbance regimes. We will collaborate with representatives from the BC Ministry of Forests and Range, BC Parks and Ministry of Environment, the Cities of Nelson and Cranbrook and local forest management companies such as Tembec, to identify segments of the landscape significantly altered by human land use and fire suppression that require ecological restoration and/or mitigation to protect economic and cultural resources.