克里雅河流域荒漠-绿洲交错带3种不同生活型植物的光合特性

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 克里雅河流域荒漠-绿洲交错带3种不同生活型植物的光合特性 DOI: 10.5846/stxb201310302623 作者: 作者单位: 中国科学院新疆生态与地理研究所,新疆大学资源与环境科学学院,中国科学院新疆生态与地理研究所,新疆大学资源与环境科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然基金新疆联合项目(U1138303); 国家自然科学基金项目 (31000166, 31260112) Photosynthetic characteristics of three different life-form plants in the desert-oasis ecotone of Keriya River Basin Author: Affiliation: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences,College of Resources and Environment Science, Xinjiang University,,College of Resources and Environment Science, Xinjiang University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:利用LI-6400光合仪测定新疆克里雅河流域荒漠-绿洲交错带自然生长的芦苇、柽柳、胡杨叶片的气体交换参数及环境影响因子,通过对比3种植物光合特性的差异及其与环境因子间的关系,探讨3种植物对荒漠环境的适应特性和机制。结果表明:(1) 3种植物叶片Pn日变化均呈不对称的双峰曲线,"午休"现象明显,Pn日均值的大小依次为胡杨> 芦苇> 柽柳,种间差异不显著。(2) Tr、PAR和Gs与3种植物Pn的日变化存在极显著或显著的相关关系,其中影响芦苇Pn的主要因子是Tr、PAR和Gs,作用效应为Tr > Gs > PAR;影响柽柳Pn的主要因子是Tr、Gs,作用效应为Tr > Gs;影响胡杨Pn的主要因子是Tr。(3) 3种植物的光合作用对光强和CO2的响应特征可用二次方程描述;光补偿点和饱和点均为柽柳> 胡杨> 芦苇;CO2补偿点为胡杨> 柽柳> 芦苇,饱和点为胡杨> 芦苇> 柽柳。(4) 3种植物的表观量子效率在0.0341-0.0411 mol/mol之间,羧化效率在0.0480-0.0546 mol m-2 s-1之间。综合比较表明,3种干旱区植物在自然条件下日均净光合速率、光能利用率和CO2同化能力差异不显著,气孔限制是光合"午休"现象产生的主要原因;影响3种植物光合作用的主导因子各不相同,但Tr与Pn间的关系较其它因子更为密切。 Abstract:Vegetation plays an important role in preventing wind erosion, sand fixation, water conservation and ecosystem restoration in oasis ecosystem. For the photosynthetic characteristics could fairly reflect the adaptation of plants to their habitat, gas exchange parameters and environmental factors of three different life-form plants which grown in the desert-oasis ecotone of Keriya River Basin were measured. By comparing the photosynthetic characteristics of Phragmites australis, Tamarix ramosissima, Populus euphratica and their relationship with environmental factors, adaptive capacities and mechanisms of the three different life-form plants were discussed. The results were as follow: The diurnal variation in net photosynthetic (Pn) rate of the three plants showed two peaks, which displayed remarked photosynthetic "midday depression". The order of the average values of Pn was: P. euphratica > P. australis > T. ramosissima. However, there was no significant difference among them. The analysis of partial correlation and path on Pn and environmental factors showed that the diurnal variation of Pn had significant correlation with transpiration rate (Tr), photosynthetically active radiation (PAR), and stomatal conductance (Gs), respectively. Tr, PAR and Gs were the main factors which affected Pn of P. australis and the order of effecting ability was Tr > Gs > PAR. Tr, and Gs were the main factors which affected Pn of T. ramosissima and the order of effecting ability was Tr> Gs. Tr was the only main factor which affected Pn of P. euphratica. For the three kinds of plants, the Pn-PAR response curves and Pn-CO2 response curves had the same changing tendency, which could be quantitatively described by quadratic equation, respectively. The order of light compensation points and light saturation points were both T. ramosissima > P. euphratica > P. australis. The order of carbon dioxide compensation points was P. euphratica > T. ramosissima > P. australis and the order of saturation points were P. euphratica > P. australis> T. ramosissima. The apparent quantum yield and carboxylation efficiency of these three plants were varied from 0.0341 to 0.0411 mol/mol and 0.0480 to 0.0546 mol m-2 s-1 on daily basis, respectively. The results indicated that the average net photosynthetic rate, energy efficiency and CO2 assimilation capacity were not significantly different among the three kinds of plants, and the photosynthetic "midday depressions" was mainly resulted from stomatal limitation. The main factors which affected physiological process of photosynthesis are different among the three different life-form plants, but the relationship between Tr and Pn is closer than other factors. 参考文献 相似文献 引证文献