广东省茂名油页岩废渣堆放场主要树种的叶片气孔气体交换

在茂名油页岩废渣堆放场主要绿化树种中选取青梅(Vaticamangachapoi)、海南红豆(Ormosiapinnata)和非洲桃花心木(Khayasenegalensis)3种植物进行测定。结果表明,3种植物的净光合速率的大小有明显的差异,从大到小的顺序是非洲桃花心木>海南红豆>青梅,海南红豆和非洲桃花心木的光合速率日变化幅度较大,而青梅的则相对较小;气孔导度从大到小依次为非洲桃花心木>海南红豆>青梅;三者净光合速率的差异与气孔导度有关。非洲桃花心木虽然具有较高的净光合速率,但由于其气孔导度较高,散失的水分较多,其内在水分利用效率比海南红豆低。青梅下午的内在水分利用效率比上午高得多,是由于其气孔导度下午比上午明显降低而限制了蒸腾失水的缘故。在油页岩废渣场,海南红豆和非洲桃花心木比青梅具有较强的生态适应性。

Stomatal Gas Exchange in Leaves of Major Trees on the Oil Shale Residue in Maoming, Guangdong

Based on a survey of the major trees grown on oil shale residue in M ao ming, Guangdong, three species, (Vatica mangachapoi, Orm os ia pinnata, and Khaya senegalensis) were chosen f rom 3 5 tree species for further study of their adaptation to such environment. The re sults showed that the net photosynthetic rates of the 3 species were sign ificant ly different, with a ranking of K. senegalensis > O. p inna ta > V. mangachapoi. Diurnal variations of net photosynt hetic rat e in K. senegalensis and O. pinnata were great while that in V. mangachapoi was less. The ranking of their stomat al conducta nces was K. senegalensis > O. pinnata > V. manga chapoi. The difference in net photosynthetic rate among the th ree trees wa s related to the stomatal conductance. Though the net photosyntheti c rate in K . senegalensis was higher, its intrinsic water use eff iciency was l ower than that in O. pinnata due to more water loss. The intrinsic wate r use efficiency of V. mangachapoi was much higher i n the afternoon because of the lower stomatal conductance. The results indicate that K. se negalensis and O. pinnata might be more adapt able to the spec ial environment.