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风速是森林生态系统研究中最为重要的变量之一,同时也是控制气流运输过程最基本的要素。由于树木生理指标和生长过程对风速的改变十分敏感,因此风速随高度的变化规律,即风速廓线的研究十分重要。一般认为,在裸地或林冠上的风廓线均呈对数规律变化,但是在单株树木和林分内风速随高度的变化则不呈对数规律。本文根据最近在海岸松林内风的研究结果,总结了针叶树种单株树木内、林分内和林冠上层以及海岸林区的风速廓线变化规律,其主要结论如下:1)单株针叶树树冠内的风速廓线呈指数形式分布,2)在林分内的风速廓线可用风的减弱系数来表示,3)[(267347)(300252317337324332301326271332262343)]上的分布可由风廓线参数(摩擦速度、粗糙长度、零平面位移)确定,4)在海岸林区,极端风速的分布可以使用了建筑上的风荷载模型进行预测。另外,本文提出了该研究领域尚需进一步探讨的问题,主要包括:1)风速廓线与树木特征及林分特征间的关系,2)利用简单的方法预测了风速廓线参数,3)风速廓线在树木生理、生态研究的作用、树木生长过程中风的微生态学效应以及森林生态和管理应用等方面。图4表1参60。
Wind speed is one of the most important variables in the study of forest ecosystem, and it is also the most essential factor to control the air transport process. Because the physiological indexes of trees and the growth process are very sensitive to the change of wind speed, the variation of wind speed with height, that is, the research of wind speed profile, is very important. It is generally believed that the wind profile on the bare land or the canopy varies logarithmically, but the logarithm of the wind speed varies with altitude within the individual trees and stands. Based on the results of recent studies on the internal winds of pine forests in the coast, this paper summarizes the changes of wind speed profile in coniferous trees, within the stands and in the canopy, and in the coastal forest areas. The main conclusions are as follows: 1) Of the wind profile is exponential, 2) the wind profile within the stand can be expressed as the wind attenuation coefficient, 3) [( 267 347) ( 300 252 317 The distribution over the wind profile parameters (friction velocity, roughness length, zero plane displacement) can be determined by the following formula: 4) In coastal forested areas, the distribution of extreme wind speeds can be predicted using the building’s wind load model. In addition, the paper proposes some problems to be further explored in the research field, including: 1) the relationship between wind speed profile and tree characteristics and stand features; 2) the wind speed profile parameters are predicted by a simple method; 3) Profile in the tree physiology, the role of ecological research, the micro-ecological effects of wind in the process of tree growth and forest ecology and management applications. Figure 4 Table 1 reference 60.