生态环境学报Issue(2)：251-257,7.
天气类型与地下水位对胡杨和灰胡杨PSII光化学效率的影响
Effects of groundwater levels and different weather states on the chlorophyll fluorescence characteristics of P. euphratica and P. pruinosa
摘要
Abstract
Populus euphratica and Poulus pruinosa are keystone species of desert ecosystems, their existence and development affect the structure, function and sustainable development of the Tarim desert ecosystem. They are precious in Tarim basin for their great ecological, economical and social benefits. In this work, We studied the effect of groundwater depths and different weathers on the photochemical efficiency of PSII, excitation energy dissipation and photosystem health of the P. euphratica and P. pruinosa with a portable fluorometer (PAM-2100). The results showed that the actual photochemical efficiency of PSII in the light(ΦPSI ), photochemistry quenching (qP), potential photosynthetic activity(Fv/Fo), the maximal photochemical efficiency of PSII (Fv/Fm), maximal fluorescence(Fm), electron transportation activity(Fm/Fo)and the ratio of absorbed light in the photochemistry(P)of these two tree species decreased from sunny days to cloudy days and with increasing groundwater depth, whereas the non-photochemistry quenching (NPQ), the ratio of the antenna thermal dissipation (D) and the excess excited energy(E) increased remarkably in the same conditions. But Fv/Fm of both tree species could well maintain optimum values (close to 0.80) under different habitats. The chlorophyll fluorescence parameters of both species were affected significantly by high light and groundwater depth interaction. The interactions between strong sunlight and groundwater depth enhanced the chance of the PSII damage, significantly inhibitedΦPSI and decreased the percentage of the PSII photochemical reaction energy, which resulted in lower photosynthesis. But these two species had good stress-resistances and self-regulation mechanisms, which can improve NPQ and E to alleviate injuries on the photosynthetic apparatus and always keep higher activities of photosynthetic electron transportation, this contributed to their high photosynthetic capacity. The percentages of the absorbed light allocation of both species were affected significantly by the high light and groundwater depth interactions. The P. euphratica could maintain higher P and increase D to decrease the level of injuries under different habitats. It indicated the P. euphratica had stronger ecological adaptation than the P. pruinosa. The P of these two tree species decreased while D and E increased with groundwater depth descending. But the P.pruinosa had higher E and lower P, D than the P. euphratica, which indicated the P. euphratica could reasonably allocate the absorbed light energy and maintain a higherΦPSI and photosynthetic activity in drought conditions. In summary, the P. euphratica has a higher self-adjustment ability and ΦPSI , it could maintain an optimum strategy of the absorbed light allocation under various stresses than the P.pruinosa and this is the primary reason why it has a wider distribution and survival than the latter species in the extreme arid desert area in the Tarim Basin.关键词
胡杨/灰胡杨/天气类型/地下水位/叶绿素荧光参数/生态适应机制Key words
Populus euphratica Oliv./Poulus pruinosa Schrenk/groundwater level/weather states/chlorophyll fluorescence parameters/ecological adaptation mechanism分类
农业科技引用本文复制引用
王海珍,陈加利,韩路,徐雅丽..天气类型与地下水位对胡杨和灰胡杨PSII光化学效率的影响[J].生态环境学报,2013,(2):251-257,7.基金项目
国家自然科学基金项目(30960033 （）
31260058) （）
国家973前期预研专项(2011CB411909 （）
2012CB426507) （）
