国家自然科学基金项目“土壤斑块异质性下荒漠草原植被空间格局及其形成机制” (32001117); 中国林业科学研究院生态保护与修复研究所结余经费专项资金 (XJS202002)
[目的] 探讨不同植被恢复措施下土壤理化性质的空间分布特征，为半干旱沙区植被恢复提供理论依据。[方法] 以毛乌素沙地西南边缘3种典型植被恢复模式(封育草地、飞播林地和人工柠条林地)为研究对象，以退化草地为对照，通过采集0—40 cm范围内3个土层的土壤，研究了其土壤理化指标和土壤综合肥力。[结果] ①在不同措施下土壤表层(0—10 cm)含水量显著增加，而在深层(10—40 cm)土壤则显著降低；与之相反的是土壤表层容重显著降低，而在深层土壤差异不显著，呈现弱变异；植被恢复显著降低了上层(0—20 cm)土壤pH值，而对20—40 cm土层差异不显著；此外，同一植被类型下随着土层加深土壤含水量(SWC)、容重(BD)、pH值均逐渐增加。②不同措施下土壤有机质(SOM)、全氮(TN)含量显著增加，封育样地SOM最高，飞播样地土壤TN最高，而速效磷(AP)含量显著降低，土壤全磷(TP)、SOM、TN等养分含量具有表聚性，土壤AP和速效氮(AN)含量在不同植被恢复、不同土层之间存在差异性。③土壤综合肥力指数呈现为：飞播样地(0.794)>封育样地(0.662)>对照样地(0.637)>柠条林地(0.603)，即土壤质量在飞播样地最高，而在柠条林地最低。[结论] 3种植被恢复模式均对土壤各理化指标有显著影响，不同植被恢复措施导致土壤各指标在垂直剖面上发生不同程度的变异，毛乌素沙地适宜进行飞播造林，而不宜大面积种植人工柠条林。
[Objective] The spatial distribution characteristics of physicochemical properties under different vegetation restoration measures were analyzed in order to provide a theoretical basis for vegetation restoration in semi-arid sandy areas. [Methods] Three typical restoration models 〔enclosed grassland (EG), aerial seeded woodland (AS), and artificial Caragana korshinskii woodland (AK)〕 were compared against a degraded grassland (CG) used as control in the Southwest Mu Us sand land. Soil physicochemical indexes and a comprehensive soil fertility index in the 0—40 cm soil layer were analyzed. [Results] ① Soil water content (SWC) in the 0—10 cm layer significantly increased under the three different vegetation restoration measures, but decreased significantly in the 10—40 cm layer. In contrast, soil bulk density (BD) in the 0—10 cm layer decreased significantly, but there was no significant difference in 10—40 cm layer, which showed weak variation. Vegetation restoration significantly reduced soil pH value in the 0—20 cm layer, but showed no significant difference in the 20—40 cm layer. In addition, SWC, BD, and pH value increased as soil depth increased under the same vegetation restoration measure. ② Soil organic matter (SOM) and total nitrogen (TN) increased significantly, while available phosphorus (AP) decreased significantly under different vegetation restoration measures. SOM was highest in EG, but TN was highest in AS. Total phosphorus (TP), SOM, and TN exhibited surface aggregation in the soil. AP and available nitrogen (AN) were different for different restoration measures and soil layers. ③ The soil comprehensive fertility index followed the order of AS (0.794)>EG (0.662)>CG (0.637)>AK (0.603), indicating that soil quality was highest in AS, but lowest in AK. [Conclusion] Various vegetation restoration measures had significant effects on soil physiochemical properties, and resulted in different variations in soil indexes in the vertical soil profile. Aerial seeding is suitable for afforestation, while large area artificial Caragana korshinskii woodland is not suitable for the Mu Us sand land.