Impacts of wildfire on soil erosion and fine-grained sediment dynamics in forested aquatic systems

在大的时空尺度上，野火事件对森林流域的沉积物动态具有显著和可测量的影响。该项目将确定沉积物来源的响应，并在对比空间和时间尺度的加拿大北部内陆森林环境中评估沉积物（矿物和有机）通过水生系统的再分配。2004年一项成功的可行性研究表明，待调查的一个研究集水区的沉积物系统正在对野火干扰作出反应，野火后沉积物来源和沉积物通量的变化就是证据。本项目将应用一套综合技术，将野火干扰的当代响应与长期恢复联系起来。具体而言，将进行实地抽样和实验室计划，包括三个相互关联的部分：(a)在规定（即诱发）燃烧之前和之后的山坡单位进行测量和采样，(b)配对集水区比较研究（即自然燃烧的集水区和附近具有相似特征的未燃烧集水区）和(c)古湖泊学研究，探索已知火灾历史的湖泊集水区沉积沉积物特性的变化。工作将在对比空间尺度（山坡到集水区）和火灾历史（现在、最近、几十年和几个世纪）的研究领域进行。这些结果将用于了解集水区对火灾的反应，以便将短期过程知识与沉积过程的长期数据联系起来，以便为调查森林燃烧的潜在影响情景提供工具。

Wildfire events have a significant and measurable impact on the sediment dynamics of forested catchments over wide spatial and temporal scales. This project will determine the response of sediment sources and evaluate sediment (mineral and organic) redistribution through aquatic systems due to wildfires in northern interior forest environments in Canada over contrasting spatial and temporal scales. A successful feasibility study in 2004 indicated that the sediment system in one of the study catchments to be investigated is responding to wildfire disturbance, as evidenced by changing sediment sources and sediment fluxes following a wildfire. The present project will apply a suite of integrated techniques to link contemporary responses to long term recovery from wildfire disturbance. Specifically, a field sampling and laboratory programme will be undertaken comprising three interlinked parts: (a) measurement and sampling on a hillslope unit before and after a prescribed (i.e. induced) burn, (b) a paired-catchment comparative study (i.e. a naturally burnt catchment and a nearby unburnt catchment with similar characteristics) and (c) a palaeolimnological study exploring changes in deposited sediment properties in lake catchments with known fire histories. Work will be undertaken in study areas of contrasting spatial scale (hillslope to catchment) and fire history (present, recent, decades and centuries). The results of these will be utilised to understand the response of catchments to fire in order to link short-term process knowledge with longer term data on sedimentary processes, in order to provide tools for investigating scenarios of potential impacts of burning in forests.