光强对幼苗光合特性的影响及不同耐阴性物种功能性状的差异

发布时间：2018-05-29 00:30

本文选题：光环境 + 光合特性　；参考：《中山大学》2017年硕士论文

【摘要】：光作为森林中的一种限制性资源,影响着植物的生存、生长和繁殖的整个生活史周期。耐阴性则是衡量植物对低光环境耐受能力的指标。因此,研究光对植物的影响以及这种影响在不同耐阴性的植物间的差异,对于理解群落构成、森林演替等问题具有重要意义。我选取了广东黑石顶自然保护区内的6个具有不同耐阴性的树种,通过进行温室幼苗种植实验,测量三个光强梯度(高/中/低光)下幼苗光响应曲线来研究不同光照强度对植物幼苗光合特性的影响。通过混合效应模型分析,我发现低光环境会显著降低植物幼苗的光合能力和暗呼吸强度,而季节和生长阶段对于光合特性的影响则因种而异。但是野外16个种的数据表明透光率对多数光合特性和叶性状没有影响,森林中幼树的光合能力和暗呼吸强度显著高于相同光环境下温室的幼苗。我进一步搜集了黑石顶样地中145个种的9个功能性状,并且使用标准化主轴回归(SMA)模型分析了一种新的耐阴性指数与功能性状的关系。我发现透光率与多数种的幼树(DBH5cm的个体)分布有显著正相关关系而且这种关系随着耐阴性增大而增强;耐阴性与物种的光合特性、木材密度和最大树高都有显著的相关关系,而与叶性状的关系并不显著。
[Abstract]:As a restricted resource in forest, light affects the whole life cycle of plant survival, growth and reproduction. Negative tolerance is a measure of plant tolerance to low light conditions. Therefore, it is of great significance to study the effects of light on plants and the differences between different negative tolerant plants for understanding community composition and forest succession. I selected six species with different negative tolerance in Heshiding Nature Reserve, Guangdong Province, and conducted greenhouse seedling planting experiments. The light response curves of three light intensity gradients (high / medium / low light) were measured to study the effects of different light intensity on photosynthetic characteristics of plant seedlings. Through the mixed effect model analysis, I found that low light environment can significantly reduce the photosynthetic capacity and dark respiration intensity of plant seedlings, but the effects of season and growth stage on photosynthetic characteristics vary with species. But the data of 16 species in the field showed that the light transmittance had no effect on most photosynthetic characteristics and leaf characters. The photosynthetic ability and dark respiration intensity of young trees in forest were significantly higher than those in greenhouse under the same light environment. I further collected 9 functional traits of 145 species in the Blackstone topsoil, and analyzed the relationship between a new negative tolerance index and functional traits by using the standardized spindle regression (SMA) model. I found that there was a significant positive correlation between the transmittance and the individual distribution of DBH 5cm in most species, and this relationship increased with the increase of tolerance to negativity, and there was a significant correlation between tolerance to light transmission and photosynthetic characteristics of the species, wood density and maximum tree height. The relationship between leaf traits and leaf traits was not significant.
【学位授予单位】：中山大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S718.43

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