Characteristics of soil enzyme activities in different degraded gradient grasslands on the Tibetan Plateau

Soil enzymes are important in nutrient cycling, material circulation, energy flow, and metabolism in the ecosystem. We determined the soil physical and chemical properties, and enzyme stoichiometry, and explored the driving mechanism along a degraded gradient on Tibetan Plateau alpine meadow and steppe. The results showed that: 1) Soil total nitrogen, total carbon, total phosphorus, organic carbon, compactness, moisture content, β-1,4-N-acetylglucosaminidase, leucine aminopeptidase, and β-1,4-glucosidase exhibited a decreasing trend, while soil temperature and pH increased with the aggravation of degradation in both alpine meadow and steppe; 2) Pearson correlation analysis showed that pH was significantly negatively correlated with β-1,4-glucosidase activity and lignin peroxidase, while organic carbon and total carbon were positively correlated with β-1,4-glucosidase and lignin peroxidase in alpine meadow. The moisture content and compactness in alpine steppe were positively correlated with leucine aminopeptidase, alkaline phosphatase, urease, and β-1,4-N-acetylglucosaminidase. The study provides a theoretical basis for exploring the variation mechanism of soil physical and chemical properties and enzyme activity under different degradation gradients, and grassland ecosystem restoration in Tibetan Plateau.