新疆策勒绿洲外围四种多年生植物的水分生理特征

对新疆策勒绿洲外围多年生植物胡杨、柽柳、沙拐枣和骆驼刺的水分生理特性进行了试验研究.结果表明：4种植物在生长季内没有受到严重的水分胁迫，灌溉对植物水分生理指标变化的影响不显著(P＞0.05).4种植物水分生理特性的季节变化各不相同.其中，骆驼刺的清晨水势和日均茎流量最高，但其平均水分利用效率最低；沙拐枣的平均水分利用效率最高，而且其清晨水势与日均茎流量的变化最为稳定，季节变幅不大；柽柳的清晨水势最低，具有较好的环境适应性；胡杨水分生理指标的季节变化相对平稳.在新疆策勒绿洲外围的极端干旱环境中，4种植物通过深根系和地下水相连接，并利用地下水来维持其生存与生长.

Water physiological characteristics of four perennial plant species around Cele Oasis in Xinjiang

The water physiological characteristics of four perennial plant species(Populus euphratica,Tamarix ramosissima,Calligonum caput-mednsae,and Alhagi sparsifolia)around Cele Oasis in Xinjiang were studied through their vegetation growth period.No signs of serious drought stress were observed in any of the test perennial species during their vegetation growth,and irrigation had little effects on the water status of the plants(P > 0.05).The seasonal variation characteristics of water physiological parameters differed with the plants.A.sparsifolia had the highest predawn water potential(PWP)and daily mean sap flow,but the lowest mean water use efficiency(WUE); C.caput-medusne had the highest mean WUE,and its PWP and sap flow were stable and had less seasonal change; T.ramosissima had the lowest PWP during its growth,and had better adaptation ability to the environment; and P.euphratica had relatively stable water physiological characteristics during its growth.The four perennial plant species had deep root systems to access underground water to satisfy their large demands for water,and thus,well adapted to the harsh environmental conditions around Cele Oasis.