Major Type of Mattic-Epipedon Ruptures in Alpine Meadow Ecosystems on the Qinghai–Tibet Plateau

Abstract

Alpine meadow degradation is an important issue for ecosystem stability in the Qinghai–Tibet Plateau (QTP). As an essential part of alpine meadow ecosystems, mattic epipedon (ME) refers to the soil surface horizons rich in organic matter and roots, which plays an important role in nutrient cycling, water retention, and ecological stability of QTP. The rupture of ME has caused serious alpine meadow degradation, biodiversity accidents, and ecosystem service decline, as well as attracted substantial concerns. However, the type of ME ruptures and their distribution environment are not well studied. In this perspective, to identify the major type of ME ruptures in QTP, 257 areas were investigated and 24 dominant plant species were collected from 2019 to 2023. Results indicated that ME ruptures exist in 234 investigated areas and can be broadly divided into 5 types based on visual observations and expert knowledge: collapsed ruptures, polygon ruptures, sheddable ruptures, cavernous ruptures, and hummock ruptures. The dominant plant species and coverage also present great differences between different rupture types. This study provides insights into alpine meadow degradation from the ME rupture types and distribution perspectives. Identifying the ME rupture types and their distribution will contribute to enhance alpine meadow restoration success for protecting the ecological benefits.