Growth responses of 15 rain-forest tree species to a light gradient: the relative importance of morphological and physiological traits
Growth responses of 15 rain-forest tree species to a light gradient: the relative importance of morphological and physiological traits
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DOI：
10.1046/j.1365-2435.1999.00332.x
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发表时间：
1999-06-01
影响因子：
5.2
通讯作者：
Poorter, L
中科院分区：
文献类型：
--
作者：
Poorter, L
1.在6种不同光照水平（3，6，12，25，50，100%光照）下，对15种热带雨林树种幼苗生长进行了比较.大多数植物变量表现出强烈的个体发育变化，它们高度依赖于植物的生物量.增长率在中等战斗水平（25 - 50%）最高，高于这一水平则下降。大多数植物变量对光照的响应呈曲线型，在最低光照水平下变化最大.不同物种之间的生长具有一致性;在弱光环境中生长迅速的物种在强光环境中也生长迅速。在弱光条件下，相对生长速率的种间差异主要由形态性状叶面积比（LAR）的差异决定，而在强光条件下，种间差异主要由生理性状净同化速率（NAR）的差异决定.在超过10 - 15%的日照下，NAR成为比LAR更强的生长决定因素。由于森林中的光可用性通常远低于这个阈值水平，因此森林环境中生长的种间差异主要是由于形态的变化。
1. Growth of seedlings of 15 rain-forest tree species was compared under controlled conditions, at six different light levels (3, 6, 12, 25, 50 and 100% daylight).2. Most plant variables showed strong ontogenetic changes; they were highly dependent on the biomass of the plant.3. Growth rate was highest at intermediate fight levels (25-50%) above which it declined. Most plant variables showed a curvilinear response to irradiance, with the largest changes at the lowest Light levels.4. There was a consistent ranking in growth between species; species that were fast growing in a low-light environment were also fast growing in a high-light environment.5. At low light, interspecific variation in relative growth rate was determined mainly by differences in a morphological trait, the leaf area ratio (LAR), whereas at high light it was determined mainly by differences in a physiological trait, the net assimilation rate (NAR).6. NAR became a stronger determinant of growth than LAR in more than 10-15% daylight. As light availability in the forest is generally much lower than this threshold level, it follows that interspecific variation in growth in a forest environment is mainly owing to variation in morphology.