Coupling ecological and geophysical processes three projects:Hydrology & riparian tree populations, Process model of fire frequency,Complex modular network of plant distribution.

生态与地球物理过程耦合三个项目：水文学

• 批准号: 7235-2013
• 负责人: Johnson, Edward
• 金额: $ 3.06万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520993
• 关键词: Coupling; ecological; geophysical; processes; three

This research program has three projects connecting ecological and geoscience processes. 1. Most riparian tree studies are for sand-silt alluvial rivers. Here we will study the population dynamics of alder on a gravel bed-bedrock river and how the populations are influenced by the hydro-geomorphic processes. A hydraulic model will be used to determine where and how seeds become stranded on shore. After stranding, these stranding locations' temperature and water potential will be used in a hydro-thermal model of seed germination to predict times of seed germination. Finally, a water budget model will determine how the plant's growth rate maintains a positive water budget, and a mechanistic model will show how plants resist (or not) the river forces causing breakage and uprooting. The model in this project will give an integrated approach to the basic causal forces acting on most riparian trees and will thus help in riparian planning. 2. Determination of landscape fire frequency has been largely statistical curve fitting. This project will start the development of a causal-based simulation with integrated: climate/ meteorological model of fuel moisture and lightning ignition, a computational fluid dynamics (CFD) model of fire spread through thermally-thin vegetative fuels, a heat transfer and combustion model of how trees are killed, and then a tree population dynamics model after and between fires. This will start the development of a fire frequency based on governing equations. 3. Vegetation is critically controlled by moisture and its distribution on a landscape. This project defines the network patterns of saturated flow (topographic wetness values) on both real landscapes and landscapes created by landscape development models in geomorphology. This approach allows an understanding of how landscape structure and the hydrological, biotic, and geomorphic processes that create landscapes explain the moisture (and nutrient) gradients that so influence vegetation distribution. The application of this understanding could provide a process basis for biophysical land classification and ecosystem landscape processes.

这项研究计划有三个项目，将生态和地学过程联系起来。1.对河岸乔木的研究多针对砂泥质冲积河流。在这里，我们将研究砾石河床-基岩河流上的赤杨种群动态，以及水文地貌过程对种群的影响。水力学模型将被用来确定种子在哪里以及如何搁浅在岸上。搁浅后，这些搁浅位置的温度和水势将被用于种子萌发的水热模型，以预测种子萌发的时间。最后，水平衡模型将决定植物的生长率如何维持正的水平衡，而机械模型将显示植物如何抵抗(或不抵抗)导致破坏和连根拔起的河流力量。本项目中的模型将对作用于大多数河岸树的基本因果作用力提供一个综合的方法，从而有助于河岸规划。2.景观火灾频次的确定在很大程度上是统计曲线拟合。该项目将开始开发基于因果的模拟，其中包括：燃料水分和闪电点火的气候/气象模型，火灾通过热稀薄的植物燃料传播的计算流体动力学(CFD)模型，树木如何死亡的热传递和燃烧模型，然后是火灾后和火灾之间的树木种群动力学模型。这将启动基于控制方程的火灾频率的开发。3.植被受到水分及其在景观上的分布的严格控制。该项目定义了真实景观和地貌学景观发展模型所创建的景观上的饱和水流(地形湿度值)的网络模式。通过这种方法，可以理解景观结构以及形成景观的水文、生物和地貌过程如何解释影响植被分布的水分(和养分)梯度。这一认识的应用可以为生物物理土地分类和生态系统景观过程提供过程基础。