Regolith-tree-atmosphere water transport on bedrock, rock joints, and talus and wildfire-mesoscale coupled models

本研究项目的目标是通过关注生态过程与地圈、水圈和大气过程之间的综合联系，加强对生态系统过程的理解。***我们的第一组项目是模拟将野火、燃料和天气动态与单个植物和种群水平上野火的生态影响联系起来的过程。该项目建议将野火过程模型与中尺度天气模型耦合（相互作用）。重要的进展是一个完整的火灾行为-火灾生态-大气模型的开始，可以在操作情况下进行测试。该模型可用于野火的后推和预测（Bakhshaii 2008; 2012）。创新是在多个尺度上耦合天气，并使用同化方法来提高北方和亚高山森林中野火行为（火焰长度、烟雾分布、蔓延速度和蔓延模式）的准确性。本文提出的模型是燃烧过程和大气过程之间的耦合系统。这是当前火灾热输出和蔓延速度与温度、相对湿度的相关性的一个重要变化。降水和风变成了一个耦合燃烧和流体动力学过程模型，换句话说，它显示了火是如何起作用的，并受到它与中尺度天气相互作用的影响。我们的第二组项目是解释树木如何在加拿大落基山脉的三个极端但丰富的栖息地生存，这些栖息地很少被研究，占该地区的一半以上。重要的是，这些工程结合了地貌、水文和生态过程，这些丰富的山地生境在这些山地水塔的水量收支中起着重要作用。该方法是将水分收支模型作为土壤-根-茎-叶-大气连续的水流来理解它们的调节。此外，稳定同位素的使用将能够确定各种来源（降水、岩石、节理、距骨或不同岩石类型）的水被树木蒸腾所需的时间长度。影响树木生长的因素各不相同。悬崖生境具有应力节理和层理面，土壤少，供水有限，因此水应力高。距骨（碎石）有距骨运动，表面层有较大的岩石，次表面层有较小的沉积物（即排水良好的地表和较湿润的地下）。因此，树木必须应对连根拔起和缺水的竞争过程。基岩山坡的第三生境具有不同的基岩类型和坡角，从而在很短的距离内改变土壤深度和供水。**

This research program's goal is to enhance understanding of ecosystem processes by focusing on the integrative connections between ecological processes and the geosphere, hydrosphere, and atmosphere processes. ***Our first set of projects is to model the processes that connect wildfire, fuel, and weather dynamics to the ecological effects of the wildfire at the individual plant and population levels. The project proposes coupling (interacting) a wildfire process model to a mesoscale weather model. The significant advance is the beginnings of a complete fire behaviour-fire ecology- atmospheric model that can be tested in operational situations. This model can be used for hindcasting and forecasting of wildfires (Bakhshaii 2008; 2012). The innovation is the coupling of weather at multiple scales and in the use of assimilation methods to improve accuracy of wildfire behaviour (flame length, smoke distribution, rate of spread and pattern of spread) in boreal and subalpine forests. The model proposed here is a coupled system between the combustion and atmospheric processes. This is an important change in viewpoint from the current correlations of fire heat output and rate of spread with temperature, relative humidity. precipitation and wind to a coupled combustion and fluid dynamics process model, in other words showing how the fire works and is influenced by its interaction with mesoscale weather. ***Our second set of projects is to explain how trees survive on three extreme but abundant habitats in the Canadian Rockies that are rarely studied and make up more then half of the area. The significance is that these projects combine geomorphic, hydrologic, and ecologic processes and that these abundant mountain habitats play an important role in the water budgets of these mountain water towers. The approach is to model the water budgets as a soil-root-stem-leaf-atmosphere continuum of water flow to understand their regulation. In addition, the use of stable isotopes will allow determination of the length of time it takes for water from various sources (precipitation, in rocks, in joints, in talus or different rock types) to be transpired by trees. The factors affecting trees on each habitat are different. The cliff habitat has stress joints and bedding planes that have little soil and limited water supply and hence high-water stress. Talus (scree) have talus movement and a surface layer of larger rocks and the subsurface layer of smaller sediment (i.e. well drained surface and moister subsurface). Consequently, the trees have to deal with the competing processes of uprooting and water stress. The third habitat of bedrock hillslopes has varied bedrock types and slope angles and thus varied soil depth and water supply over very short distances. **