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尼区克兰布鲁克附近的约瑟夫-金溪流域和不列颠哥伦比亚省东南部西库特尼区尼尔森附近的西阿姆省立公园的五英里-拉斯卡溪流域。理论火-植被模型表明，这两个地区的历史火情差异很大。我们的研究验证了人类土地利用、灭火和气候变化的综合影响使这两个地点的火灾状况均质化的假设。目前，这两个地点发生严重火灾的风险都很高，主要是由于东库特尼研究区干旱森林的火灾排除，以及西库特尼研究区更湿润的森林日益频繁的干旱。我们将使用一种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尼西部和东部两个地区的气候、植被和火灾的历史。湖泊沉积物的古生态学研究将量化1000至10000年间火情和森林组成的变化。树木生态学（树木年轮）分析将通过(a)重建过去300至500年的气候，(b)通过分析火灾痕迹量化历史火灾频率，以及(c)调查年际至年代际气候变化对火灾状况的影响来解决这些变化发生的机制。最终，我们的目标是(a)在空间和时间上量化火灾频率和严重程度的自然变异性范围，(b)预测不同气候变化情景影响下的未来火灾状态，以及(c)预测气候变化和改变干扰状态影响下的未来优势植被。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部和环境部、纳尔逊市和克兰布鲁克市以及坦贝克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发生重大变化的景观部分，这些部分需要生态恢复和/或减灾措施，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.