【摘要】 通过野外的实际观测,研究2龄、3龄和4龄植物群落区的土壤水分差异及其对梭梭(Haloxylonammodendron)蒸腾耗水的影响。结果表明:(1)种群年龄增加,土壤水分显著降低,裸地、2龄、3龄、4龄种群0~200 cm土层年平均土壤水分含量分别为74.40,66.08,52.71 mm和49.23 mm;(2)生长初期,不同年龄间梭梭蒸腾速率差异不明显,盛夏,3龄梭梭蒸腾速率最大,生长后期,梭梭蒸腾速率随群落年龄增加而减小;(3)种群年龄增加,梭梭长势停滞,水分消耗减少,2龄、3龄和4龄梭梭平均株高分别为71,132,75 cm,平均冠幅分别为54 cm×57 cm,80 cm×123 cm,58 cm×63 cm,年均蒸腾耗水分别为33 603.0,98 827.1,32 231.5 g。选择合理的密度配置方式,对维持人工植物群落与土壤水分的相对稳定具有十分重要的作用。更多还原

【Abstract】 Through a field experiment conducted in the hinterland of the Gurbantonggut Desert,in this study,the dynamic water regime in the soil and its effects on the transpirations of 2～4-year-aged artificial mixed communities of Haloxylon ammodendron,spacing regularly at 2 m×1 m,are observed.The artificial communities are consisted of two dominant plant species,Haloxylon ammodendron and Calligonum caput-medusae,which were planted for one year in nursery before transplanted.The results are as follows:(1) The mean annual soil moisture content within 0～200 cm of soil layer under the communities decreases evidently with the increase of community age,figuring at 74.40 mm,66.08 mm,52.71 mm and 49.23 mm respectively in the bare area(controlled),two-year-aged,three-year-aged and four-year-aged communities;(2) In spring and early summer,there are no differences in transpirations of the 2～4-year-aged communities of Haloxylon ammodendron;in mid-summer,the transpiration of three-year-aged community of Haloxylon ammodendron is highest;in late summer and autumn,the transpirations of the communities of Haloxylon ammodendron decreases with the increase of their age;(3) As the community age goes up,the soil water stress to the growth of Haloxylon ammodendron is increased,and the growth of plants is delayed by the reduction of water consumption.For example,the mean annual water consumption of the 2～4-year-aged communities of Haloxylon ammodendron with average heights of 71 cm,132 cm and 75 cm and average canopy extents of 54 cm×57 cm,80 cm×123 cm and 58 cm×63 cm were 33 603.0 g,98 827.1 g and 32 231.5 g,respectively.In order to reduce the deficit of soil moisture supply and sustain the artificial mixed community,a suitable spacing between Haloxylon ammodendron and Calligonum caput-medusae should be selected.更多还原