【摘要】 通过测定刺楸、黄连木、栾树旱季和雨季气体交换参数及其周围环境因子的日变化,分析水分生理生态特性,探讨各生理生态因子对水分利用效率的影响。结果表明:光合有效辐射与温度均呈单峰型,空气相对湿度呈"U"型。蒸腾速率日变化3个树种在旱季和雨季均呈单峰型。净光合速率日变化刺楸在旱季为双峰型,在雨季为单峰型,而黄连木、栾树在旱季和雨季均为单峰型。水分利用效率日变化在雨季3个树种呈单峰型,在旱季黄连木呈单峰型,而刺楸和栾树呈双峰型。逐步回归分析发现,影响3个树种水分利用效率的因子主要有胞间CO2浓度(极显著负相关)、大气CO2浓度(极显著正相关)、空气相对湿度(正相关)和叶温(负相关)等。通过主成分分析,可将影响刺楸、栾树水分利用效率的因子归纳为3类,即温度、气孔导度和CO2浓度;黄连木可归纳为两类,即温度和气孔导度。更多还原

【Abstract】 Gas exchange parameters and water use efficiency of Pistacia chinensis Bunge,Kalopanax septemlobus Koidz and Rekoelreuteria paniculata Laxm were studied under different environmental factors in order to explore the effects of environmental factors on the water use efficiency. The results of diurnal changes were as follows: Photosynthetically active radiation and temperature were synchronous and presented as single-peak curves, while air relative humidity as "U" curve. Transpiration rates were single-peak curves both in dry and rainy season. Photosynthesis rate of Kalopanax septemlobus Koidz was a double-peak curve in dry season, and the rests were all single-peak curves. Water use efficiency were all single-peak curves in rainy season, but in dry season that of Pistacia chinensis Bunge was a single-peak curve and the rest were both double-peak curves. By means of stepping multi-regression analysis the four extremely remarkable and relevant factors were intercellular CO₂ concentration, atmosphere CO₂ concentration, air relative humidity and leaf temperature. The results of primary components suggested that the influencing factors of water use efficiency of Pistacia chinensis Bunge can be classified into two kinds that were temperature and stomatal conductance, while that of the rest can be classified into three kinds which were temperature, stomatal conductance and CO₂ concentration.更多还原