草业科学2025，Vol.42Issue(8)：1922-1933,12.DOI:10.11829/j.issn.1001-0629.2024-0304
三江源区土壤酶活性与微生物养分限制对高寒草地退化与恢复的响应
Response of soil enzyme activity and microbial nutrient limitation to alpine grassland degradation and restoration in the Three Rivers Headwaters Region
摘要
Abstract
Microbes play an important role in carbon cycling and nutrient flow of the soil ecosystem;however,the response of microbial activity during the degradation and restoration of alpine grasslands is poorly understood.Therefore,to investigate how grassland degradation and artificial restoration affect soil resource acquisition enzyme activity and microbial nutrient limitation,we selected alpine grasslands with different degrees of degradation(non-degraded,lightly degraded,moderately degraded and heavily degraded)and restoration years(3,8,13 and 19 years)in the Three Rivers Headwaters Region.We collected 0-10 cm soil samples,explored the response of resource acquisition enzyme activity and their stoichiometry,and evaluated microbial nutrient limitation status.The experimental results show that as the degree of degradation deepens,the activities of all resource acquisition enzymes decrease significantly(P＜0.05).With the increase in restoration years,the carbon acquisition enzyme activity decreased significantly.In contrast,the nitrogen and phosphorus acquisition enzyme activity showed an increasing trend,starting with the minimum values observed in the 13-year restoration plot(P＜0.05).Enzyme stoichiometry analysis shows that grassland degradation significantly exacerbates microbial carbon limitations.After the intervention of artificial restoration measures,microbial carbon limitation showed a trend of initially increase and later decrease,whereas microbial nitrogen limitation consistently increased(P＜0.05).Variance partitioning analysis and Spearman correlation analysis showed that resource acquisition enzyme activity was jointly affected by soil total nutrients,available nutrients,and microbial biomass.In contrast,microbial nutrient limitation was more affected by soil total nutrients and microbial biomass.Our study shows that alpine grassland degradation will aggravate microbial carbon limitations,and measures such as fertilization and reseeding in the early recovery period will alleviate carbon limitations.However,fencing measures after short-term fertilization and reseeding will put microbes into relatively severe nutrient limitations,requiring a longer recovery time.Therefore,appropriate nutrient input is more conducive to the recovery of the alpine grassland ecosystem and sustainable development for long-term fenced restored grasslands.关键词
三江源区/高寒草地/草地退化/土壤酶化学计量学/矢量分析/微生物养分限制Key words
Three Rivers Headwaters Region/alpine grassland/grassland degradation/soil enzyme stoichiometry/vector analysis/microbial nutrient limitation引用本文复制引用
王巧红,杨艳,李袁泽..三江源区土壤酶活性与微生物养分限制对高寒草地退化与恢复的响应[J].草业科学,2025,42(8):1922-1933,12.基金项目
陕西省创新人才推进计划科技创新团队项目(2023-CX-TD-37) （2023-CX-TD-37）
