College of Grassland Science, Gansu Agricultural University, Lanzhou, 730070, China.
J Environ Manage. 2024 Aug;366:121841. doi: 10.1016/j.jenvman.2024.121841. Epub 2024 Jul 15.
Grassland ecology is deteriorating along with a fall in biodiversity and ecosystem services as a result of climate change in the Mediterranean regions. Understanding the mechanism of feedback between soil properties related to available water and increasing aridity is a key component of preserving grassland ecosystems. Structural equation modelling was used to explore a deep understanding of the underlying mechanisms of the feedback between soil properties related to available water and increasing aridity. In most cases, vegetation patches had significantly higher soil properties related to available water than inter-patches. Compared to inter-patches, the fine fractions of silt and clay content, soil organic carbon, saturated hydraulic conductivity, and available water under vegetation patches increased by 3.79%-7.64%, 31.08%-37.64%, 96.65%-141.14%, and 2.63%-9.21%, respectively, under limestone and mica schist lithologies. The fine fractions of silt and clay content, soil organic carbon, and available water were more responsive to the aridity index than the vegetation patch, while saturated hydraulic conductivity was more responsive to the vegetation patch than the aridity index. These complex relationships demonstrated that the available water was significantly positively affected by the vegetation pattern (0.09) and the aridity index (0.21-0.38). Soil texture had a significantly direct effect (0.43-0.53) on available water. Increasing aridity would strengthen the contrast in soil water availability while weakening the contrast in saturated hydraulic conductivity between vegetation patches and inter-patches. Available water was controlled by many aspects except vegetation pattern and aridity index. Understanding these relationships helped in predicting and mitigating the impacts of climate change on soil properties related to available water. The study offered fresh perspectives on the mechanism of vegetation pattern and aridity index on the various soil properties related to available water in arid and semiarid grasslands ecosystems under climate change.
随着气候变化，地中海地区的生物多样性和生态系统服务下降，草原生态系统也随之恶化。了解与可利用水相关的土壤特性与干旱加剧之间反馈的机制是保护草原生态系统的关键组成部分。结构方程模型被用于深入探讨与可利用水相关的土壤特性与干旱加剧之间反馈的潜在机制。在大多数情况下，植被斑块的土壤特性与可利用水明显高于斑块间。与斑块间相比，在石灰岩和云母片岩岩性下，植被斑块下的土壤细颗粒（粉粒和黏粒）、土壤有机碳、饱和导水率和可利用水分别增加了 3.79%-7.64%、31.08%-37.64%、96.65%-141.14%和 2.63%-9.21%。土壤细颗粒（粉粒和黏粒）、土壤有机碳和可利用水对干旱指数的响应大于植被斑块，而饱和导水率对植被斑块的响应大于干旱指数。这些复杂的关系表明，可利用水受到植被模式（0.09）和干旱指数（0.21-0.38）的显著正向影响。土壤质地对可利用水有显著的直接影响（0.43-0.53）。干旱加剧会加强植被斑块和斑块间土壤水分有效性的差异，同时减弱饱和导水率的差异。可利用水受到许多方面的控制，不仅仅是植被模式和干旱指数。了解这些关系有助于预测和减轻气候变化对与可利用水相关的土壤特性的影响。该研究为气候变化下干旱和半干旱草原生态系统中植被模式和干旱指数对与可利用水相关的各种土壤特性的影响机制提供了新的视角。
