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

The soil in the root zones of Haloxylon ammodendron, Nitraria sphaerocarpa, and Calligonum mongolicum in the desert-oasis ecotone in the northern part of Linze County, Gansu Province was selected as the research object. In July - September 2020, soil samples at different soil layer depths and different horizontal distances from the root zones of sand-fixing plants were collected, and the organic matter, total N, and total P indicators in the soil samples were detected and analyzed. The results showed that: 1) The nutrient contents in the soil of the Haloxylon ammodendron root zone were generally greater than those in the root zones of Nitraria sphaerocarpa and Calligonum mongolicum, and the spatial variation degree of each nutrient content in the soil of the Haloxylon ammodendron root zone was relatively larger than that of Calligonum mongolicum and Nitraria sphaerocarpa. 2) The soil nutrient content at a horizontal distance of 0 - 0.5 m in the root zone of sand-fixing plants was greater than that at a horizontal distance of 1.5 - 2.0 m, and the accumulation effect of Haloxylon ammodendron on soil nutrients was greater than that of Nitraria sphaerocarpa and Calligonum mongolicum, indicating that Haloxylon ammodendron can effectively preserve a large amount of its own litter and root exudates, etc., and is an ideal sand-fixing plant. 3) With the increase in soil layer depth, the organic matter content in the soil of the root zone of sand-fixing plants basically showed a trend of first increasing and then decreasing, and the total P and total N contents showed a trend of being higher in the surface layer. 4) There were significant positive correlations among soil organic matter, total N, and total P in the root zone of sand-fixing plants. The soil nutrient distribution characteristics in the root zones of different sand-fixing plants in the desert-oasis ecotone determine the spatial pattern of sand-fixing vegetation in the ecotone and have practical significance for further scientifically and rationally selecting sand-fixing plants.

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。