在洪泽湖调蓄灌溉与南水北调常态化调水影响下,湖区水位显著波动对湿地土壤水分及植被生长产生深刻影响.以江苏洪泽湖湿地典型杨树林为对象,借助涡度相关及土壤水分监测系统,研究湿地土壤-杨树系统水分的时空动态变化特征,解析气象因子的影响,为洪泽湖湿地杨树林的水分管理和科学经营与保护提供理论依据.结果表明:湿地杨树林土壤水分的年内变化可以大致分为稳定期(10-2月,31.36％～36.07％),消耗期(3-4月,36.64％～37.46％),积累期(5-7月,39.22％～53.92％)和消退期(8-9月,40.38％～32.92％)等4个阶段;春、 夏和冬3季的土壤含水量的日变化曲线呈单峰型特征,而秋季表现为不对称双峰曲线特征.土壤水分随着土壤深度(0～40 cm)的增加而逐渐增加.土壤水分变化与日降水量、 日平均气温、 日平均相对湿度、 日平均土壤温度呈极显著正相关(P<0.01),与日平均感热通量、 平均风速呈极显著负相关(P<0.01).气象因子中,日平均土壤温度和日平均相对湿度对土壤水分的影响最为明显,其贡献率分别为10.73％～57.97％和18.62％～25.12％.图4表2参37%With storage irrigation and normal diversion of water from south to north, water level fluctuations in Hongze Lake have had a profound impact on soil moisture and the growth of wetland vegetation. To provide a theoretical basis for water management along with scientific management and protection of the poplar forest in Hongze Lake Wetland, spatial and temporal variations of soil moisture on a wetland system of poplar and their correlation with meteorological factors were analyzed using the system of eddy covariance and soil moisture monitoring. Results showed that over a year in the Hongze Lake Wetland the change of soil moisture in the poplar plantation could be divided into a stable period (October-February: 31.36％-36.07％), a consuming pe-riod (March-April: 36.64％-37.46％), an accumulating period (May-July: 39.22％-53.92％), and a subsiding period (August-September: 40.38％-32.92％). The diurnal variation of soil moisture in spring, summer, and winter exhibited mono-peak curves; whereas, two-peak curves occurred in autumn. Also, soil moisture increased with an increasing soil depth (0-40 cm). In addition, soil moisture in the poplar plantation was highly signifi-cant (P<0.01) and positively correlated with daily precipitation (r = 0.203-0.378), daily mean air tempera-ture (r = 0.462-0.549), daily average relative humidity (r = 0.397-0.510), and daily mean soil temperature (r =0.549-0.862); it was also highly significant (P<0.01) and negatively correlated with daily mean sensible heat flux (r = -0.238--0.482) and average wind speed (r = -0.293--0.430). Among these variables, the most ob-vious effect on soil moisture was with daily mean soil temperature (contributing 10.73％-57.97％ to soil mois-ture) and daily average relative humidity (contributing 18.62％-25.12％. Based on the above analysis, an ad-vice when we plant poplar using the method of ditching and ridging is put forward. [Ch, 4 fig. 2 tab. 37 ref.]
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