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为定量研究华北落叶松人工林水分利用特征,2010年5-10月在宁夏六盘山北侧叠叠沟林场的华北落叶松人工林固定样地内,通过测定树干径向生长、林分叶面积指数变化、草本生物量变化、树干液流速率变化、植物降雨截持等,估计了华北落叶松人工林及各层的生产力、水分消耗和水分利用效率。研究表明:林分总生产力11.76t/hm2,其中乔木层占75.2%,草本层占24.8%;在整个生长期内,林分生产力各月的分量呈现先升高后降低的季节变化格局。林分总蒸散量为433.9mm,其中乔木层与草本层(包括土壤蒸发)耗水各约占一半,分别为总蒸散的50.5%和49.5%;林分蒸散在生长季中呈现先升高后降低的季节变化格局。在整个生长季,华北落叶松人工林的水分利用效率为2.71g/kg,其中乔木层的水分利用效率为4.04g/kg,草本层水分利用效率为1.36g/kg;其季节变化与乔木层的水分利用效率变化相类似,说明乔木层对于华北落叶松林分水分利用效率的影响较大。
In order to quantitatively study the water use characteristics of Larix principis-rupprechtii plantations, from May to October in 2010, the Larix principis-rupprechtii Mayr. Plantation was planted in the Zuzidou Forest Farm on the northern side of Liupan Mountains in Ningxia. The leaf area index Changes in biomass, changes in the biomass of the herbs, changes in the flow rate of the sap flow, and interception of rainfall in plants, etc. The productivity, water consumption and water use efficiency of the Larix principis-rupprechtii plantation and its layers were estimated. The results showed that the total stand productivity was 11.76 t / hm2, including 75.2% of tree layer and 24.8% of herb layer. During the whole growth period, the monthly productivity of each component showed a seasonal pattern of increasing firstly and then decreasing. The total evapotranspiration of the stands was 433.9 mm, of which, the water consumption of the arbor layer and the herb layer (including soil evaporation) each accounted for about half, accounting for 50.5% and 49.5% of the total evapotranspiration, respectively; Reduce the seasonal pattern. Throughout the growing season, the water use efficiency of Larix principis-rupprechtii plantation was 2.71 g / kg, in which the water use efficiency of arbor layer was 4.04 g / kg and the water use efficiency of herb layer was 1.36 g / kg. The seasonal variation of arbor layer Similar to the changes in water use efficiency, indicating that the tree layer on the Larix principis-rupprechtii stand water use efficiency.