荒漠绿洲过渡带不同固沙植物根区土壤养分空间分布特征

选取甘肃省临泽县北部的荒漠绿洲过渡带梭梭、泡泡刺、沙拐枣根区的土壤为研究对象，于2020年7-9月采集固沙植物根区不同水平距离处不同土层深度的土壤样品，检测分析土壤样品中的有机质、全N和全P指标。结果表明:1）梭梭根区土壤中各养分含量总体上大于泡泡刺与沙拐枣根区，且梭梭根区土壤中各养分含量的空间变异程度相对沙拐枣、泡泡刺较大。2）固沙植物根区水平距离0~0.5 m处的土壤养分含量大于水平距离1.5~2.0 m处，且梭梭对土壤养分的蓄积作用大于泡泡刺与沙拐枣，说明梭梭可以将大量的自身凋落物和根部分泌物等进行有效保蓄，是一种理想的固沙植物。3）随着土层深度的增加，固沙植物根区土壤中有机质含量基本上都呈现出先增高后降低的趋势，全P、全N含量呈现出表层较高的趋势。4）固沙植物根区的土壤有机质、全N、全P之间均呈显著正相关关系。荒漠绿洲过渡带不同固沙植物根区的土壤养分分布特征，决定了过渡带上固沙植被的空间格局，对进一步科学合理地选择固沙植物具有现实意义。

Spatial Distribution Characteristics of the Soil Nutrients in Root Zones with Different Sand Fixing Plants in the Transition Zone of Desert Oasis

The distribution characteristics of the soil nutrients in the root zones of different sand fixing plants in the desert-oasis ecotone determine the spatial pattern of sand fixing plants in the transition zone,which is of practical significance for the further scientific and reasonable selection of sand fixing plants.Taking the desert-oasis transition zone in the northern Linze County of Gansu Province as the research area,the soils in the root zones of Haloxylon ammodendron,Nitraria sphaerocarpa,and Calligonum mongolicum were selected as the research objects.The soil samples of different root zones of sand fixing plants were collected from July to September 2020.The soil samples collected from different soil depths at horizontal distances were tested and analyzed for the organic matter,total nitrogen and total phosphorus indicators.The results showed that 1) the contents of various nutrients of the soils in the root zone of H.ammodendron were generally higher than those of N.sphaerocarpa and C.mongolicum,and the spatial variability of the nutrient contents in the root zone of H.ammodendron was larger than N.sphaerocarpa and C.mongolicum.2) The soil nutrient contents at horizontal distance 0-0.5 m in the root zone of sand fixing plants were greater than at 1.5-2.0 m,and the accumulation effect of H.ammodendron on soil nutrients was greater than N.sphaerocarpa and C.mongolicum,indicating that H.ammodendron is an ideal sand fixing plant,which can effectively store a large amount of its own litter and root exudates.3) With the increase of soil depth,the organic matter content in the root zone of sand fixing plants basically increased first and then decreased,and the contents of total phosphorus and total nitrogen showed a trend of higher in surface layer.4) There was a significantly positive correlation among soil organic matter,total nitrogen,and total phosphorus in the root zone of sand fixing plants.