塔里木河中下游胡杨叶内外水汽压差和气孔导度对蒸腾速率的生理影响  

Physiological Effects of Leaf-air Vapor Pressure Deficit and Stomatal Conductance on Transpiration Rate of Populus euphratica in the Middle and Lower Reaches of Tarim River

作　　者：林兵 武胜利[1] 管文轲[2] 宋川 LIN Bing;WU Shengli;GUAN Wenke;SONG Chuan(School of Geographical Science and Tourism,Xinjiang Normal University/Xinjiang Key Laboratory of Lake Environment and Resources in Arid Areas,Urumqi 830054,China;Xinjiang Academy of Forestry,Urumqi 830054,China)

机构地区：[1]新疆师范大学地理科学与旅游学院/新疆干旱区湖泊环境与资源重点实验室,新疆乌鲁木齐830054 [2]新疆林业科学院,新疆乌鲁木齐830054

出　　处：《广东农业科学》2020年第8期47-55,共9页Guangdong Agricultural Sciences

基　　金：新疆维吾尔自治区林业厅科技支撑专项(HY-2.3)。

摘　　要：【目的】研究速生期内胡杨蒸腾速率影响机制和适应干旱气候环境的生理调控,为塔里木河中下游胡杨林的人工更新复壮提供依据。【方法】采用便携式光合仪于2018年6—8月对极端干旱区塔里木河沿岸天然荒漠胡杨(Populus euphratica)林进行实测,分析胡杨蒸腾速率Tr与叶内外水汽压差VPDL、气孔导度Gs的相关性。【结果】观测期内胡杨Tr和Gs日变化呈"单峰"曲线,峰值出现时间不同,7月Tr和Gs呈"双峰"曲线。VPDL均呈"单峰"曲线,峰值时间在16:00。Tr和VPDL峰值时间均出现不同程度的滞后Gs峰,滞后性强。出现"双峰"曲线主要是受非气孔限制因子的影响,导致Tr和气孔导度Gs达到第一峰后,下降而后上升再下降。胡杨Tr和VPDL、Gs均呈二次曲线,叶内外水汽压差、气孔导度是调控蒸腾速率的重要因子。观测期内胡杨Tr受到气孔限制和非气孔限制交替影响,各月气孔和非气孔限制所影响的时间段不尽相同,并对植物造成不同的生理反馈。【结论】塔里木河中下游地区胡杨Tr对VPDL响应敏感度高于对Gs,非气孔限制也是维持水分平衡的重要机制。【Objective】The transpiration rate mechanism of Populus euphratica during the fast growing period and the physiological regulation to adapt to arid climate environment were studied so as to provide experimental basis for the artificial regeneration of P.euphratica forest in the middle and lower reaches of the Tarim River.【Method】The portable photosynthesis instrument was used to measure the natural P.euphratica along the Tarim River in the extreme arid area in June to August of 2018.The measured data was used to study the correlation between transpiration rate (Tr) of P.euphratica and leaf-air vapor pressure deficit (VPDL) and stomatal conductance (Gs).【Result】The diurnal variation of Tr and Gs of P.euphratica showed a single-peak curve during the observation period,and the peak occurrence time was different.In July,the trend of Tr and Gs showed a bimodal curve,and VPDL had a single-peak curve with a peak time at 16:00 The peak times of Tr and VPDL showed different degrees of hysteresis compared with the peak of Gs,with strong hysteresis.The occurrence of the bimodal curve was mainly affected by the non-stomatal limiting factors,which caused Tr and Gs to reach the first peak.After that,Tr and Gs decreased first and then rose and finally fell.All of Tr,VPDL and Gs of P.euphratica exhibited a quadratic curve model,indicating that leaf-air vapor pressure deficit and stomatal conductance were both important factors regulating the transpiration rate.During the observation period,P.euphratica was alternately affected by stomatal limitation and non-stomatal limitation.The period of each month affected by the stomatal and non-stomatal limitation was different,therefore,there were different physiological and ecological reflections on plants.【Conclusion】The response sensitivity of P.euphratica Tr to VPDL is higher than that of Gs in the middle and lower reaches of the Tarim River.Non-stomatal restriction is also an important mechanism to maintain water balance.

关 键 词：胡杨 叶内外水汽压差 气孔导度 蒸腾速率 干旱区 

分 类 号：S792.119[农业科学—林木遗传育种] S727.2[农业科学—林学]