The temporal-spatialotemporal differentiation characteristics and self-repairing law patterns of soil nutrients in a mining area in western China

Abstract

This study explores the environmental changes in the disturbed area of coal mining and presents the driving factors of ecological self-restoration. Specifically, we measured the soil nutrient and soil enzyme indicators in the mining area and non-mining area from 2014 to 2017 and 2019, and evaluated the stoichiometric characteristics of soil carbon (C), nitrogen (N), and phosphorus (P). The experimental results show that the total phosphorus concentration gradually recovered with the increase of mining years, while organic matter, available potassium, and urease first increased and then decreased with the increase of mining years. There were significant differences in total phosphorus, C/N ratio, N/P ratio, and C/P ratio between the working face and the subsidence disturbance zone. Random forest analysis showed that soil sucrase, urease, available potassium, total nitrogen, total phosphorus, C/P ratio, C/N ratio, and water-soluble salts were the key factors influencing soil nutrient cycling in different time periods; while C/N ratio, N/P ratio, total phosphorus, alkaline phosphatase, and water-soluble salts were the key factors influencing soil nutrient cycling at different locations. Mining years of the working face has differing influence path on soil factors and soil enzymes. This study could provide theoretical proof for the artificial guided self-restoration plan in coal mining subsidence areas and for ecological restoration in western mining areas.

Keywords

• mining subsidence
• self-healing
• ecological stoichiometry
• soil nutrients
• soil factors