放牧
环境科学
氮气循环
矿化(土壤科学)
微生物种群生物学
农学
生态学
生物
氮气
土壤水分
化学
细菌
遗传学
有机化学
作者
Na Li,Ruiying Chang,Hui Jiang,Akash Tariq,Jordi Sardans,Josep Peñuelas,Feng Sun,Xingmei Zhou
出处
期刊:Catena
[Elsevier BV]
日期:2022-08-24
卷期号:219: 106589-106589
被引量:13
标识
DOI:10.1016/j.catena.2022.106589
摘要
• Grazing-exclusion significantly decreased soil enzyme activities at around 4000 m altitudes. • Grazing-exclusion significantly decreased alpine meadow root biomass. • Grazing-exclusion and warming significantly increased soil fungal biomass. • Light-intensity grazing is beneficial to potential N mineralization in an alpine meadow. Alpine meadows play a key role in maintaining biodiversity, soil nutrient retention, and herders’ livelihoods in mountain regions. Livestock grazing-exclusion is common in grassland management to protect and promote the sustainable use of alpine meadows. However, there are few studies evaluating the effects of traditional light grazing practices in alpine regions and grazing-exclusion impacts on soil nutrient, especially under conditions of climate warming. In this study, we conducted a five-year grazing-exclusion and warming manipulation experiment to examine the effects of grazing-exclusion on soil nitrogen fractions, microbial communities, and enzyme activities under climate warming. Treatments consisted of light-intensity grazing, grazing-exclusion, and combined grazing-exclusion and warming. Our results showed that grazing-exclusion significantly decreased potential nitrogen mineralization at a 0–5 cm depth and at altitudes of 3850 m, 4000 m, 4150 m, and 4250 m. Combined grazing-exclusion and warming also significantly decreased potential nitrogen mineralization at a 0–5 cm depth and at relatively higher altitudes of 4000 m, 4150 m, and 4250 m. Grazing-exclusion, combined grazing-exclusion and warming all shifted microbial communities from bacteria toward fungi. Grazing-exclusion significantly decreased the relative abundances of phylum Chloroflexi (bacteria) and phylum Ascomycota (fungi), while combined grazing-exclusion and warming significantly increased the relative abundances of phylum Basidiomycota (fungi). The relative abundances of phylum Ascomycota (fungi) demonstrated a positive relationship with potential nitrogen mineralization, but the relative abundances of phylum Basidiomycota (fungi) had a negative relationship with potential nitrogen mineralization. The activities of dehydrogenase and protease in grazing-exclusion and combined grazing-exclusion and warming meadows were lower than those in grazed meadows. Our results demonstrated that in the context of climate change and global warming, grazing-exclusion is unsuitable as a tool for the sustainable management of alpine meadows from soil nitrogen mineralization and fractions point of view. Of concern, climate warming could potentially amplify the adverse effects of grazing-exclusion and causes depletion of soil nutrients in the alpine meadow. This research suggests that a light-intensity grazing (0.5 yak ha −1 year −1 ) is beneficial to increase soil enzyme activity and N mineralization in alpine meadows. Our results provide substantial evidence and a useful baseline and guidance for the sustainable grazing management of alpine meadows as environments change due to climate warming in the future.
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