摘要
土壤线虫是土壤中数量最丰富的后生动物,其能量动态对维持土壤生态系统功能至关重要,但线虫能量通量如何影响土壤有机碳储量仍然未知.为探究秸秆还田对酸性红壤食物网中线虫能量通量及土壤碳组分的影响,本研究依托中国科学院鹰潭红壤生态实验站设置的秸秆还田培肥长期试验,探究了不施肥(no fertilizer,CK)、化肥(NPK chemical fertilizers,N)、化肥+秸秆还田(NPK chemical fertilizers with straw,NS)、化肥+秸秆猪粪配施(NPK chemical fertilizers with straw and pig manure,NSM)4种处理下线虫生态指数、能量通量及土壤碳组分的变化.结果表明,NS和NSM处理显著提高了土壤有机碳含量及线虫生物量和能量通量.线虫成熟指数、富集指数和结构指数的提升表明,秸秆还田改善了土壤食物网的养分状况和稳定性.秸秆提供了丰富的碳源和营养,促进了微生物生长,而猪粪配施进一步增强了微生物活性.同时,“快速”和“慢速”通道的能量通量均增加,支撑了更高的线虫能量通量.食细菌线虫(cp-1类群)的增加主导了NSM处理下细菌能量通量及矿物结合态有机碳(mineral-associated organic carbon,MAOC)的积累,而颗粒态有机碳(particulate organic carbon,POC)主要受捕杂食线虫能量通量的影响.这表明食细菌线虫通过促进细菌代谢活动增强了MAOC的形成,而捕杂食线虫通过调控食物网能量流动影响了POC的积累.本研究为提升红壤肥力、保障粮食安全提供了理论依据.
Soil nematodes are the most abundant metazoans in terrestrial ecosystems and play a crucial role in maintaining soil ecosystem functions through their energy dynamics.However,the mechanisms by which nematode energy fluxes influence soil organic carbon(SOC)stocks remain poorly understood.This study investigated how nematode food web energy flux responds to different straw return treatments and the effect this has on soil carbon fractions in acidic red soils.The study was based on a 12-year long-term fertilization experiment conducted at the Yingtan National Agro-Ecosystem Observation and Research Station of the Chinese Academy of Sciences.The experiment included four treatments:(1)no fertilizer(CK);(2)NPK chemical fertilizer(N);(3)NPK chemical fertilizer with straw return(NS);and(4)chemical fertilizer with a combined application of straw and pig manure(NSM),with a carbon input ratio of 9:1 for straw to manure.We analyzed nematode community structure and ecological indices,including maturity,enrichment,and structure indices,as well as metabolic footprints and energy fluxes.We also examined the relationships between these factors and different SOC fractions(particulate organic carbon,POC;mineral-associated organic carbon,MAOC;and microbial biomass carbon,MBC).Our results demonstrated that the NS and NSM treatments significantly increased SOC content,with the NSM treatment having the most pronounced effect,increasing SOC by 67%compared to the CK treatment.These improvements were accompanied by substantial changes in nematode communities:total nematode abundance in the NSM treatment increased 3.6-fold relative to the CK treatment,with bacterivorous nematodes(Ba)forming the dominant trophic group(with a relative abundance of 40.5%-50.3%).Notably,the NSM treatment elevated the maturity index(MI),enrichment index(EI),and structure index(SI)of nematode communities,indicating the development of a more mature and stable soil food web.Energy flux analysis revealed that both‘fast’(bacterivore-dominated)and‘slow’(omnivore-predator regulated)energy channels were enhanced under straw return treatments.Specifically,the increase in cp-1 taxa bacterivorous nematodes(opportunistic taxa)was strongly associated with elevated bacterial energy flux and subsequent MAOC accumulation,contributing 6.7%to the total variation.In contrast,the energy flux of omnivorous-predatory nematodes(OP)had the greatest influence on POC dynamics,contributing 7.4%.These findings suggest that nematode energy fluxes regulate SOC accumulation through distinct pathways:(1)the‘fast’channel,where bacterivorous nematodes promote microbial turnover and necromass formation to facilitate MAOC stabilization;and(2)the‘slow’channel,where omnivorous nematodes influence POC through trophic cascades that modulate microbivore and herbivore populations.Furthermore,NSM treatment demonstrated synergistic effects,enhancing total energy flux 10-fold compared to the CK treatment.This study sheds new light on the mechanisms by which nematode-mediated energy fluxes regulate SOC stocks in red soils.The findings emphasize the importance of incorporating soil fauna energy dynamics into carbon cycling models and indicate that the combined application of straw and manure is an effective strategy for improving soil fertility,carbon storage,and crop productivity in subtropical red soil regions.These results have significant implications for the development of sustainable agricultural practices in the context of food security.
作者
石广萍
郑洁
彭紫怡
王晓玥
周顺桂
刘佳
蒋瑀霁
Guangping Shi;Jie Zheng;Ziyi Peng;Xiaoyue Wang;Shungui Zhou;Jia Liu;Yuji Jiang(Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Soil and Fertilizer&Resources and Environment Institute,Jiangxi Academy of Agricultural Sciences,Nanchang 330200,China;Ecological Experimental Station of Red Soil,Chinese Academy of Sciences,Yingtan 335211,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《科学通报》
北大核心
2025年第28期4891-4901,共11页
Chinese Science Bulletin
基金
国家重点研发计划(2023YFD1900300)
国家自然科学基金(42425704,42177298,42307396)
江苏省卓越博士后基金(2023ZB565)资助。
关键词
线虫网络
能量通量
生态指数
颗粒态有机碳
矿物结合态有机碳
nematode network
energy flux
ecological index
particulate organic carbon
mineral-associated organic carbon
