The trade-offs of ecological functions during community restoration in Stipa grandis steppe

Stipa grandis steppe as one of the main community types of temperate grasslands in Northern China plays important roles in livestock production and ecological security. Current grassland degradation research links climate change and human activities to soil properties, community traits, and ecosystem functions, but the relationships of plant traits, diversity and ecosystem function remain unclear. To achieve sustainable development of temperate grassland ecosystem, there is a fundamental need to explore the current situations of Stipa grandis steppe and the trade-offs of ecological functions during restoration. We conducted experiments on 120 Stipa grandis community plots (5 m x 5 m) at different restoration stages based on field investigation in Inner Mongolia, China. The relationships of plant traits, diversity, plant organic carbon storage and soil organic carbon storage are analyzed, and the trade-offs of related ecological functions during grassland restoration are explored. The results show that (1) Enclosure effectively promotes plant organic carbon storage, specific leaf area, specific root length, and soil organic carbon concen-tration of Stipa grandis. (2) Compared with A1 stage (heavy grazing with 1.8-2.7 sheep ha1 half year-1), enclosure effectively promotes species diversity and functional diversity of Stipa grandis community. (3) Soil carbon storage shows a significant positively correlation with functional diversity in the early stage of grassland restoration, and a significant positively correlation with species diversity in the late stage of grassland restoration. (4) B2 stage (enclosure lasting 8-14 years) has higher function trade-offs and lower functional benefits, which is the critical stage for plant diversity and soil organic carbon storage. Our findings highlight plant traits and community function of Stipa grandis steppe during restoration, which provide scientific basis necessary to promote grassland sustainability and restoration in similar areas.