8种木本植物木质部栓塞变化与生理生态指标间关系的研究(II)——与光合生理生态指标的关系

选取西北农林科技大学西林校区校园内自然状况下生长良好的耐旱树种刺槐(Robin iap seudoacacia)、元宝枫(A cer truncatum)、沙棘(H ippophae rhamnoid es)、白榆(U lmus pum ila)、油松(P inus tabu laeform is)、白皮松(P inus bungeana)及中生树种女贞(L igustrum lucidum)、柳树(S a lix m atsud ana K o idz.f.pendu la)为研究对象,测定了它们3个季节内的木质部栓塞日变化规律及其与光照强度、大气温度、气孔导度、蒸腾速率等生理生态指标的关系。结果表明:光照强度、大气湿度和大气温度主要是通过对植物气孔运动、蒸腾作用和体内水分关系的调节对木质部栓塞起作用的;木质部栓塞是植物一天生长过程中不可避免的“平常事件”,与植物的光合速率、蒸腾速率、气孔导度和水分利用效率间存在一定的相关关系;它的发生和恢复可能是某些植物适应水分胁迫的一种机制。

Relationships between Xylem Embolism and Ecophysiological Indexes in Eight Woody Plants in situ(II):-The Relationship with Photosynthetic Ecophysiological Indexes

The relationship between xylem embolism and ecophysiological indexes(i.e.photosynthetic available radiation,temperature,relative humidity,photosynthetic rate,transpiration rate,stomatal conductance and water use efficiency) in eight tree species was measured in situ.The tree species are Robinia pseudoacacia L.,Acer truncatum Bge.,Hippophae rhamnoides L.,Ulmus pumila L.,Pinus tabulaeformis Carr.,Pinus bungeana Zucc.ex Endl., Ligustrum lucidum Ait.,Salix matsudana Koidz.f.pendula Schneid.grown well on Xi-lin campus of Northwest A&F University.The results indicated that available photosynthetic radiation,air temperature and relative humidity could affect xylem embolism by adjusting stomatal conductance,transpiration rate and water relations of a tree in one day.Embolism was a common case in the daily growth of the plants,there were some correlations between xylem embolism and photosynthetic rate,transpiration rate,stomatal conductance,and water use efficiency.The embolism and refilling might be a mechanism adaptable to water stress for some tree species.