Vegetation restoration has been proposed as an effective measure for rehabilitating degraded land and slowing desertification in arid regions. However, the spatial variation in soil quality and plant diversity following vegetation restoration remains unclear. This study was designed to explore soil nutrient dynamics and how soil nutrients affect plant diversity and spatial heterogeneity after shrub restoration. We assessed the effect of Haloxylon ammodendron (C.A.Mey.) Bunge (which has been planted over 30 years) on the soil nutrients and plant diversity in a desert–oasis ecotone in Minqin County, Gansu, China, using geostatistics, beta diversity and rarefaction analyses, and Hill number extrapolation. Soil nutrients, including soil organic matter, total nitrogen, and alkali nitrogen, increased significantly after H. ammodendron planting. Species richness gradually increased from 1–5 years to 10–20 years after H. ammodendron was planted but then decreased at 20–30 years. The largest differences in plant composition were observed at 15 and 20 years. Plant diversity increased in the whole 30 years after shrub planting, increasing in the first 25 years and then decreasing at 26–30 year stage. The maximum coefficient of determination for the spatial heterogeneity model fit was 0.84 (25 years). The spatial heterogeneity in vegetation decreased with increasing soil available K content at 1–10 years. Our results suggest that planting shrubs can improve soil conditions and plant species diversity in desert–oasis ecotones and soil nutrients have a strong influence on plant diversity patterns and spatial heterogeneity following vegetation restoration.

中文翻译：

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荒漠-绿洲交错带植被恢复对土壤养分，植物多样性及其时空异质性的影响

提出了恢复植被作为恢复干旱地区退化土地和减缓荒漠化的有效措施。然而，植被恢复后土壤质量和植物多样性的空间变化尚不清楚。本研究旨在探讨灌木恢复后土壤养分动态以及土壤养分如何影响植物多样性和空间异质性。我们评估了Haloxylon ammodendron的效果（CAMey。）利用地统计学，β多样性和稀疏性分析以及希尔数外推法（已经种植了30年）在甘肃民勤县荒漠绿洲过渡带的土壤养分和植物多样性上进行了邦吉研究。梭菌种植后，土壤养分（包括土壤有机质，总氮和碱氮）显着增加。变形虫后，物种丰富度从1-5年逐渐增加到10-20年被种植，但在20–30年时下降。在15年和20年观察到最大的植物组成差异。在灌木种植后的整个30年中，植物多样性有所增加，在开始的25年中有所增加，然后在26-30年阶段有所减少。空间异质性模型拟合的最大确定系数为0.84（25年）。1-10年间，植被的空间异质性随着土壤有效钾含量的增加而降低。我们的结果表明，种植灌木可以改善荒漠绿洲过渡带的土壤条件和植物物种多样性，而土壤养分对植被恢复后的植物多样性模式和空间异质性具有强烈影响。