论文部分内容阅读
为了比较中国东南沿海防护林主要树种的光合特性及水分利用策略,利用LI-6400便携式光合作用仪和PAM-2100叶绿素荧光仪对福建沿海防护林5个主要树种的光合特性以及荧光特性进行测定,并采用稳定同位素技术量化这些植物的水分来源利用比例以及水分利用效率。4种红树植物的光合同化速率、气孔导度、蒸腾速率显著高于木麻黄(Casuarina equisetifolia);外来红树植物无瓣海桑(Sonneratia apetala)光合同化速率显著高于3个乡土红树植物。无瓣海桑叶片的最大相对电子传递速率(rETRmax)、半饱和光强(Ek)、Fv/Fm均显著大于乡土红树植物,表明无瓣海桑光合能力大于其他红树植物。植物茎木质部水稳定同位素的测定表明,外来种木麻黄和无瓣海桑主要利用地下水,而未利用海水和雨水;3种乡土红树植物主要利用地下水,但也利用海水和雨水的混合水。木麻黄的瞬时水分利用效率显著低于4种红树植物,但4种红树植物间的瞬时水分利用效率无显著差异。秋茄(Kandelia obovata)和无瓣海桑的长期水分利用效率无显著差异,但二者显著高于桐花树(Aegiceras corniculatum)、白骨壤(Avicennia marina)及木麻黄,说明前二者对水分的利用优于后三者,更适应于水分成为植物生长与存活限制因子的高盐环境。
In order to compare the photosynthetic characteristics and water use strategies of the main tree species in coastal shelterbelt in southeastern China, the photosynthetic characteristics and fluorescence characteristics of five main species of coastal shelterbelts in Fujian Province were determined by LI-6400 portable photosynthesis apparatus and PAM-2100 chlorophyll fluorescence instrument. Stable isotope techniques quantify the water source utilization of these plants and their water use efficiency. The photosynthetic rate, stomatal conductance and transpiration rate of four mangrove species were significantly higher than those of Casuarina equisetifolia. The photosynthetic rate of the exotic mangrove Sonneratia apetala was significantly higher than that of three native red Tree plant. The maximum relative electron transfer rate (rETRmax), half-saturation intensity (Ek) and Fv / Fm of leafless sea cucumber were significantly higher than that of native mangrove plants, indicating that photosynthetic capacity of S. atelopeum was higher than that of other mangrove plants. The determination of the stable isotopes of xylem in plant stems showed that the native species of ephedra and non-petal seaweed mainly use groundwater, but not seawater and rainwater. The three native mangroves mainly use groundwater, but also the mixed water of seawater and rainwater. The instantaneous water use efficiency of Casuarina equisetifolia was significantly lower than that of four mangrove species, but there was no significant difference in instantaneous water use efficiency among the four species. The long-term water use efficiency of Kandelia obovata and Anemarrhena asphodelus had no significant difference, but both were significantly higher than Aegiceras corniculatum, Avicennia marina and Casuarina, indicating that the former two had good water use efficiency The latter three are more adapted to the high salt environment in which moisture becomes a limiting factor for plant growth and survival.