权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Researhes on controll mechanism of leafarea index and light shading in tree crowns

叶面积指数与树冠遮光控制机制研究

基本信息

批准号：
05640711
负责人：
KOIKE Fumito
金额：
$ 1.34万
依托单位：
Shimane University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640711/
关键词：
Foliage Crown Canopy Leaf area index Projection matrix Shoot 3-D model Boot strap method ブート・ストラップ法光樹冠間相互作用

项目摘要

This study aimed to reveal the mechanism of leaf area index of tree canopies from the stand point of leaf and shoots population dynamics. I checked following five hypotheses at the start of the study.(1) Leaf area index is controlled solely by shade tolerance. Light intensity under foliage canopy is just below the least light condition at which shoot population can be maintained.(2) Since number of large winter bud is determined by the condition of previous year, light condition under canopy in current year is usually lower than the least light condition for shoot population.(3) Old leaves of evergreen species intercept light.(4) Light intercept by trunk and branches.(5) Leaf fall after shoot development in summer controls leaf amount of canopy.From actual measurement of light condition and shoot growth, light condition is usually lower than the least light condition for shoot population (Koike 1989). Effect of trunk and branches on light condition is not very important. Usually they intercept only 30% of full light. Leaves have ten times of effects on light condition (hypothesis 4). Concerning hypothesis 5, leaf fall in summer is not usual in almost species, except for some first and continuously growing species (Kikuzawa 1986).A simulation model of foliage canopy growth was developed to evaluate the effect of hypothesis 2 and 3. This is a model of three dimensional spaces, and is modified from two dimensional model by Koike (1989). As the result of this simulation, the rate of shoot population growth (lambda) and leaf survivor rate were both effected leaf area index.For prediction of species composition and dominance by such canopy interaction model, precise estimation of leaf area index from shoot and leaf dynamically parameters are necessarily. Since shoot population dynamics effected leaf area index, a boot strap method was applied to evaluate reliability of lambda.

本研究旨在从叶和枝条种群动态的角度揭示树冠叶面积指数的机制。在研究开始时，我检查了以下五个假设。（1）叶面积指数仅由耐荫性控制。叶冠下的光照强度略低于能够维持枝条种群的最低光照条件。(2)由于大冬芽的数量由上一年的情况决定，因此当年冠层下的光照条件通常低于枝条种群的最低光照条件。(3)常绿树种的老叶拦截光线。(4)树干和枝条拦截光线。(5)夏季枝条发育后的落叶控制冠层的叶片数量。从光照条件的实际测量来看对于芽的生长，光照条件通常低于芽种群的最低光照条件（Koike 1989）。树干和树枝对光照条件的影响不是很重要。通常它们仅拦截全部光线的 30%。叶子对光照条件的影响是十倍（假设4）。关于假设 5，除了一些最初和连续生长的物种外，夏季落叶现象在大多数物种中并不常见（Kikuzawa 1986）。开发了叶冠生长模拟模型来评估假设 2 和 3 的效果。这是一个三维空间模型，由 Koike（1989）对二维模型进行了修改。作为该模拟的结果，芽种群生长率（lambda）和叶存活率均影响叶面积指数。为了通过这种冠层相互作用模型预测物种组成和优势度，有必要根据芽和叶动态参数精确估计叶面积指数。由于枝条种群动态影响叶面积指数，因此采用引导法来评估 lambda 的可靠性。