Strong earthquake results in regional die-off and degradation of alpine wetlands in the Qinghai-Tibet Plateau: Implications for management and restoration

Abstract

Strong earthquakes can have negative effects on various ecosystems, including farmlands, grasslands, and coasts. However, reports of how strong earthquakes affect the biodiversity and ecosystem functions of alpine wetlands are lacking. In the present study, investigations of soil and aquatic plants and snails were conducted to determine if and how the strong M7.4 Maduo earthquake in 2021 affected the alpine wetlands in the Qinghai-Tibet Plateau. Our results demonstrated that the Maduo earthquake resulted in the infiltration of surface water in many alpine marshes or pools near the earthquake fissures, and the ability of these alpine wetlands to restore the rainwater or meltwater declined or was even lost. The long-time disappearance of surface water directly changed the environmental conditions, decreased the contents of soil moisture and various soil nutrients and increased the soil hardness and salinity, which resulted in the die-off of aquatic plants and snails, decrease in the abundance of water birds, and finally habitat degradation. The densities of alive aquatic plants and snails were positively related to the soil moisture content and some nutrient indices, and negatively related to the soil salinity. The density of alive aquatic snails was also positively related to the density of alive aquatic plants. Additionally, in the future, these dried and degraded alpine wetlands could become a potential source or sink of soil desertification. This study also provided scientific implications for the ecosystem management and restoration of alpine wetlands after strong earthquakes. The restoration and filling of adjacent earthquake fissures and the supplementation of surface water, plants, and macrobenthos need to be carried out after a strong earthquake to protect the biodiversity and restore the alpine wetlands.