Shuitu baochi tongbao (Jun 2023)
Effects of Disturbance Modes on Vegetation and Soil in Typical Grassland Area
Abstract
[Objective] The effect of different disturbance modes on soil physical and chemical properties and vegetation characteristics of typical grassland areas in Inner Mongolia were analyzed in order to provide a scientific basis for restoring the ecological environment following road construction and for adopting reasonable restoration measures. [Methods] Three highways (G303 Xilinhot-Abaga section, G207 Xilinhot-Xiwuzhumuqin section, G207 Xilinhot-Uritutala village section) in the Xilinguole brassland area were studied. Using the method of space instead of time, the soil and vegetation characteristics of a road ecosystem under different numbers of restoration years (1, 5, 15 years) and different disturbance modes (rolling, cutting, borrow pit, embankment) were investigated. [Results] ① Disturbance mode had a significant impact on soil physical and chemical properties, and soil bulk density followed the disturbance mode order of rolling > embankment > cutting > borrow pit. As the number of restoration years increased, soil bulk density approached the bulk density of the undisturbed area. Soil moisture content followed the disturbance mode order of rolling < cutting < borrow pit < embankment, and soil moisture increased as the number of restoration years increased. Soil organic carbon, total phosphorus, and total potassium contents were lowest for the rolling disturbance mode, and highest for the embankment disturbance mode. ② The plant community richness index initially increased, then decreased, and finally stabilized. Species diversity index for the 5-year restoration period was higher than for the 15-year restoration period. ③ From the principal component analysis of relevant data, the comprehensive ranking of embankment, cutting, and borrow pit disturbance after 15 years of recovery was high, and the comprehensive scores were 2.33, 1.42 and 1.32, respectively. The comprehensive scores of rolling disturbance were the lowest, and damage to the ecosystem was the most serious. [Conclusion] There were significant differences in the physical and chemical properties and vegetation index of disturbed soil compared with undisturbed soil. The nutrient content of the filled soil was higher, while the nutrient content of the excavated soil was significantly lacking in nutrients compared with the undisturbed area. Therefore, it will be necessary to strengthen the ecological protection of disturbed areas.
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