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

该研究计划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来增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，燃料和天气动态与野火在个体植物和种群水平上的生态影响联系起来的过程。该项目建议将野火过程模式与中尺度天气模式耦合（相互作用）。重大进展是一个完整的火灾行为-火灾生态学-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报和预测（Bakhshaii &约翰逊2017）。我们已经在野火模型中纳入了树木坏死和死亡的生态效应作为子程序（Michaletz &约翰逊2006; 2008; 2012）。创新之处是将天气与多个尺度结合起来，并使用同化方法，以提高北方和亚高山森林野火行为（火焰长度、烟雾分布、蔓延速度和蔓延模式）的准确性。本文提出的模型是一个燃烧过程与大气过程的耦合系统。 这是一个重要的变化，从目前的火灾热输出和蔓延速度与温度，相对湿度的相关性的观点。降水和风耦合燃烧和流体动力学过程模型，换句话说，显示火灾如何工作，并受到其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，这些项目结合了联合收割机地貌，水文和生态过程，这些丰富的山地栖息地在这些山区水塔的水预算中发挥着重要作用。该方法是模拟的水收支作为一个土壤-根-茎-叶-大气连续体的水流，以了解其调节。此外，稳定同位素的使用将允许确定来自各种来源（降水、岩石、节理、岩屑或不同岩石类型）的水被树木蒸腾所需的时间。不同生境下影响树木生长的因子不同。悬崖栖息地有应力关节和层面，土壤和有限的供水，因此高水压力。岩屑堆（碎石）有岩屑运动，表层有较大的岩石，次表层有较小的沉积物（即排水良好的表面和较潮湿的次表层）。因此，树木不得不处理拔除和水分胁迫的竞争过程。基岩山坡的第三种生境具有不同的基岩类型和坡度，因此在很短的距离内土壤深度和供水量也不同。**

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 & Johnson 2017). We have already incorporated as a subprogram in the wildfire model the ecological effect of necrosis and mortality of trees (Michaletz & Johnson 2006; 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. **