State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an, Shaanxi 710061, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China.
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an, Shaanxi 710061, China; Interdisciplinary Research Center of Earth Science Frontier, Beijing Normal University, Beijing 100875, China; Department of Earth and Environmental Sciences, Xi'an Jiaotong University, Xi'an 710049, China.
Sci Total Environ. 2020 Nov 10;742:140498. doi: 10.1016/j.scitotenv.2020.140498. Epub 2020 Jun 23.
The intensive introduction of shrubs to drylands can alter species composition and affect a series of biotic and abiotic processes. This topic has attracted increasing attention by researchers. To assess the response of soil properties to vegetation succession in arid regions of China, we measured the soil water content (SWC) to a depth of 5-m and determined soil properties of surface (0-5 cm) and subsurface (20-25 cm) layers in areas of natural grasses (NGs) and planted shrubs (PSs). The patch size of Caragana korshinskii shrubs resulted in different soil water storage losses (small shrub patch: 206.67 ± 35.58 mm; medium shrub patch: 416.88 ± 35.12 mm; large shrub patch: 588.63 ± 72.00 mm; degraded shrub patch: 740.54 ± 17.00 mm). Shrub cover showed an initial increase but then decreased as shrubs extracted soil water from the deep soil layers (>1 m). The species richness index in the PSs decreased with increasing shrub patch sizes. Surface soil organic carbon (SOC), extractable nitrogen (NH-N and NO-N), and available phosphorous contents and saturated soil hydraulic conductivity (Ks) in the PSs were all significantly (p < 0.05) lower than those in NGs. Soil particles in the range of 0.002-0.2 mm explained 28.0% and 47.3% of the total variability of these surface indices under NGs and PSs, respectively. The differences in SOC, NH-N, NO-N, Ks, and field capacity between the surface and subsurface layers declined significantly (p < 0.05). The introduction of shrubs affected the plant community by increasing the spatial heterogeneity of soil resources (e.g. water and nutrient contents). Therefore, the strong feedback between SWC and vegetation succession should be carefully considered when revegetating drylands. The evaluation of regional soil property responses to vegetation succession aids in a better understanding of soil water-vegetation feedback and provides important implications for future revegetation in arid regions.
灌木的大量引入会改变物种组成，并影响一系列生物和非生物过程。这个话题引起了研究人员越来越多的关注。为了评估植被演替对中国干旱地区土壤性质的响应，我们测量了土壤水分含量（SWC）至 5 米深，并测定了天然草地（NGs）和种植灌木（PSs）地区表层（0-5 cm）和亚表层（20-25 cm）土壤的性质。锦鸡儿灌木的斑块大小导致不同的土壤水分储存损失（小灌木斑块：206.67 ± 35.58 mm；中灌木斑块：416.88 ± 35.12 mm；大灌木斑块：588.63 ± 72.00 mm；退化灌木斑块：740.54 ± 17.00 mm）。灌木覆盖度先增加后减少，因为灌木从深层土壤中提取水分（>1 m）。PS 中的物种丰富度指数随着灌木斑块大小的增加而降低。PS 中的表层土壤有机碳（SOC）、可提取氮（NH-N 和 NO-N）、有效磷含量和饱和土壤水力传导率（Ks）均显著低于 NGs（p < 0.05）。PS 中 0.002-0.2 mm 范围内的土壤颗粒分别解释了 NGs 和 PSs 中这些表层指数总变异性的 28.0%和 47.3%。SOC、NH-N、NO-N、Ks 和田间持水量在表层和亚表层之间的差异显著降低（p < 0.05）。灌木的引入通过增加土壤资源（如水和养分含量）的空间异质性来影响植物群落。因此，在恢复干旱地区时，应仔细考虑 SWC 和植被演替之间的强反馈。评估区域土壤性质对植被演替的响应有助于更好地理解土壤-植被反馈，并为干旱地区未来的植被恢复提供重要启示。
