干旱区生态环境知识资源中心

We studied the dominant environmental factors that affect the gas-exchange characteristics and water potential (psi) of broad-ovate leaves of Populus euphratica Oliv. in extreme arid area of Tarim River, China, and their correlation to water status of P. euphratica by analyzing on-field monitored meteorological data, soil moisture and salinity, P. euphratica leaf gas exchange and psi, and revealed the indicative threshold of environmental factors for P. euphratica leaf water changes and growth. The results indicated that meteorological factors such as air relative humidity (RH), air temperature (T (air)), etc. are the dominant factors. The threshold value of RH is (48.19 +/- 1.06)% for P. euphratica growth, i.e. RH from 10.69% to 48.19% is suitable for P. euphratica growth in extremely arid region of Tarim River. This study provides a theoretical basis for reducing drought damage to P. euphratica and maintaining normal growth of P. euphratica by in-time watering.