【作者】 戴凌峰；

【导师】 张志翔； 沈应柏；

【作者基本信息】 北京林业大学 ， 野生动植物保护与利用， 2007， 硕士

【摘要】 植物耐荫性是指植物在弱光照条件下的生活能力。植物为适应变化了的光量子密度而产生了一系列的变化,从而保持自身系统的平衡状态,并能进行正常的生命活动。耐荫植物的筛选和应用是合理建立复层种植结构、提高单位面积绿地绿化生态效益的关键措施,在模拟自然、进行城市森林建设中具有十分重要的意义,日益受到人们的普遍关注。本研究选择常见的四种灌木树种:大花溲疏、荆条、蚂蚱腿子和小桐子作为研究对象,首先对这几种灌木树种进行了不同程度的遮荫处理,用黑色遮阳网遮荫,分别置于全光照的4.8%、14.9%、46.0%以及100%四种光照条件下生长60d以上,之后进行生理学特征以及植物的光合特性等指标的测定。经过本实验,作者比较研究了遮荫对这几种灌木树种一些生理变化的影响,并对这四种灌木树种的耐荫性强弱进行了综合排序。经过研究发现,遮荫对这四种树种的生理学特征以及植物的光合特性等指标都有不同程度的影响:遮荫使植物叶片气孔密度变小、比叶重变小、叶片呼吸速率升高、叶绿素a/b的值降低、单位叶面积鲜重降低、叶片光补偿点下降、表观量子效率升高、最大净光合速率下降,适度的遮荫能增加植物叶片的相对含水量,而过度的遮荫使其相对含水量降低。对于树种种间的耐荫性综合排序结果为:蚂蚱腿子的耐荫性最强,大花溲疏次之,再次是小桐子,而荆条的耐荫性最弱。更多还原

【Abstract】 Shade tolerance of plant refers to the ability of plants to develop and grow in relatively low light conditions. To adapt to different photon flux density, plants can change their metabolic systems to maintain growth balance. The correct selection and application of shade-tolerance plants is of significance to establish comprehensive plantation structure and increase unit efficiency of green environment, which is critical step to civic forest planning.This study analyzed and measured different physical and photosynthetic index of four different shrub species: Deutzia grandiflora, Vitex negundo var. heterophylla, Myripnois dioica and Jatropha curcas under four different light conditions for more than 60 days: 4.8%、 14.9%、 46.0% and 100%, by employing black velaria.By comprehensively analyzing the shade tolerance on these four shrubs, our study suggested that shade has different effects on these four shrubs in terms of physical and photosynthetic index. Under the shade, the density of stomata for leaves decreases, the relative specific leaf weight decreases, the respiratory rate of leaves increase, the ratio of content of chlorophyll a to chlorophyll b decreases, the compensation points of leaves decrease slightly, the apparent quantum efficiencies increase and the biggest true photosynthetic rates decrease. Moderate shade increases the relative water content of leaves, but excessive shade decreases the relative water content of leaves. The order of shade tolerance from strong to weak is Myripnois dioica>Deutzia grandiflora>Jatropha curcas>Vitex negundo var. heterophylla.更多还原