湍流运动与生态边界层厚度

TURBULENCE AND THICKNESS OF ECOBOUNDARY LAYER.

通过湍流通量及其梯度的空间结构和时间变化的分析,进一步揭示了生态边界层的结构特征和功能以及植物生理活动在这一过程中的重要性。茶园枝叶密集的冠层空间是物质能量的源和汇,可视为一个具有特定功能的整体,即生态实体。生态边界层厚度是指植物生命活动与物理环境之间的直接作用距离,超出这一距离,植物与环境间的物质能量交换则不明显。茶园冠层的生态边界层厚度(D)可用公式D=(BA)表达。(BA)为植物生理活动函数,HC为植物群体高度。在中性条件下,Φ=1。当=1时,D值变化在0.08HC～0.16HC之间,在考察生态系统的环境条件时,D值具有一定的参考意义。

The structure of ecoboumdary layer and its function in the physiological activities of plants are further revealed through the analysis of the time-space variations of turbulent fluxes and their vertical gradients. In a dense tea plantation, the source and sink of material and energy are located in a part where branchlets and leaves are so crowded together as to be recognized as an entity or ecobody with specific functions when an investigation is made in a larger scale. Thickness of an ecoboundary layer is a distance between a plant and its physical environments within which they interact directly and effectively, Whereas beyond this limit no more direct interaction exists. For a tea plantation, thethickness of ecoboundary layer (D) can be approximately evaluated by the equation D=(BA) , Where HC is canopy height, (BA) is function of physiologicel activities of plants. In the case of =1, = 1, D will vary between 0. 08HC-0.16HC which is a valuable reference for investigating the environment of an ecosystem.