藏北不同类型高寒草地土壤酶活性及酶化学计量比特征

打开文本图片集

中图分类号：S812.2 文献标识码：A 文章编号：1007-0435（2025）08-2482-1

Abstract：In recent years，global warming has led to severe degradation of alpine grasslands on the Tibetan Plateau.Inthis studywe investigated the soil enzyme activities and their stoichiometric characteristics in diferent types of alpine grasslands in the Naqu region of Xizang，aiming to understand the soil nutrient status and grassland ecosystem functions.The results show thatsoil enzyme activities varied significantly among diferent grassland types （0.5245-20446U⋅g-1） ，with degraded grasslands having lower enzyme activities than nondegraded ones，except for alkaline phosphatase （AKP） and exoglucan β -1，4-glucanase （CBH）. In alpine meadows，the vector angle of soil AKP was greater than 45∘ ，indicating limitation of phosphorus nutrient. Degraded grassands had higher Enzyme C/P and Enzyme N/P ratios，suggesting microbial limitations of carbon and phosphorus，while Enzyme C/N ratios showed no significant differences. Soil organic carbon （SOC），total nitrogen （TN），total phosphorus（TP），and available phosphorus （AP） contents were the main factors afecting soil enzyme activities.Diferences in microbial biomass carbon（MBC）and microbial biomass nitrogen（MBN） contents reflect distinctions in microbial community structure and affect enzyme secretion. The differences in soil nutrient structure among diferent grassland types directly influenced enzyme secretion， leading to significant diferences.In the future，combining soil microbial community composition and functional characteristics could further reveal the mechanisms of soil nutrient cyclingand ecosystem function inalpine graslands on the Tibetan Plateau，providing effective suggestions for grassand management and ecological res toration of degraded grasslands.

Key words：Grassland degradation; Alpine grassland;Soil enzyme activity;Soil enzyme stoichiometry

高寒草地是青藏高原的关键生态系统[1]，具有涵养水源、维持养分循环、调节气候（包括固碳功能）及保持生物多样性等重要的生态功能[2-3]。（剩余19055字）