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以张家界植物园移栽的香果树、小花木荷和长果安息香幼树为试材,通过动态监测4种光合特征参数,对3个不同珍稀树种的光合特性进行比较研究,以期为珍稀树种保护提供理论依据。结果表明:3个树种间的光合特性存在明显差异,其中小花木荷光合能力最强。长果安息香、香果树和小花木荷的光合作用日变化均呈双峰型,都存在光合午休现象。小花木荷能充分利用午后丰富的光热资源,光合午休持续的时间短,故而小花木荷的光合速率要明显高于香果树和长果安息香。3个树种的Pn-PRA曲线变化趋势基本保持一致。在PRA为0~200μmol·m-2·s-1范围时,净光合速率Pn近乎呈直线上升;在PRA为600~900μmol·m-2·s-1左右时,最大值出现。但是不同树种间最大Pn存在显著差异,尤其是小花木荷光合能力远远超过其它2个树种。
In this study, the photosynthetic characteristics of three rare and endemic species were comparatively studied by dynamically monitoring four photosynthetic characteristics parameters in order to provide valuable protection for rare species Theoretical basis. The results showed that there were significant differences in photosynthetic characteristics among the three tree species, among which the photosynthetic capacity was the strongest. The daily changes of photosynthesis of longan fruit benzoin, fragrant fruit tree and small flower schizophyllum all showed bimodal type, all had the midday depression of photosynthesis. Small flowers Schiphol can make full use of afternoon light and heat resources, photosynthesis midday break duration is short, so the photosynthetic rate of Schima superba is significantly higher than the fragrant fruit and longan fruit benzoin. The trend of Pn-PRA curves of the three species basically kept the same. When the PRA was in the range of 0 ~ 200μmol · m-2 · s-1, the net photosynthetic rate (Pn) increased almost linearly. At the PRA of 600 ~ 900μmol · m-2 · s-1, the maximum appeared. However, there was a significant difference in the maximum Pn between different species, especially the photosynthetic capacity of C. armeniacum far exceeded that of the other two species.