藏北不同類(lèi)型高寒草地土壤酶活性及酶化學(xué)計(jì)量比特征
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中圖分類(lèi)號(hào)：S812.2 文獻(xiàn)標(biāo)識(shí)碼：A 文章編號(hào)：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關(guān)鍵生態(tài)系統(tǒng)[1]，具有涵養(yǎng)水源、維持養(yǎng)分循環(huán)、調(diào)節(jié)氣候（包括固碳功能）及保持生物多樣性等重要的生態(tài)功能[2-3]。（剩余19055字）