Soil fauna community characteristics and driving factors of Pinus tabuliformis in the loess region of northern Shaanxi

Abstract

This study aimed to examine the characteristics and regulatory mechanisms of the soil fauna community in Pinus tabuliformis plantations at different restoration ages. The study was conducted on the soil fauna of Pinus tabuliformis in different restoration ages (6a, 11a, 18a, and 22a) in Wuqi County. Soil fauna, soil samples, understory herb biomass were collected in the spring, summer, autumn and winter of 2021. The relationship between the soil fauna community characteristics and environmental factors were studied. The results are as follows: (1) The density increased and the number of species decreased in the soil fauna community with an increase in restoration ages, and the composition and structure of the soil fauna community were significantly different at different restoration ages. (2) The diversity of the soil fauna community was highest and the soil food web was the most stable in 6-year-old Pinus tabuliformis plantations. Followed by a 22-year-old Pinus tabuliformis plantation. The lowest soil fauna diversity and the least stable food webs were found at 11- and 18-years-old of Pinus tabuliformis plantations. (3) The understory herb community had the greatest impact on the composition and structure of soil fauna community. SOM, NCP and NHS were the main factors affecting the composition of the soil fauna community. (4) During the restoration of Pinus tabuliformis plantations, the soil fauna community is mainly controlled by the top-down food resources, and the understory herb community driven the evolution process of the soil fauna community, thereby regulating the soil food web. Our research results emphasize the importance of sub-forest herbaceous vegetation to soil animals, which is essential for the formulation of sustainable biodiversity conservation policies for planted forest ecosystems.