线虫和蚯蚓对土壤微量气体排放的影响  

Influence of nematodes and earthworms on the emission of atmospheric trace gases(CO_2,N_2O)

作　　者：罗天相[1] 李辉信[1] 王同[1] 胡锋[1] 

机构地区：[1]南京农业大学资源与环境科学学院

出　　处：《生态学报》2008年第3期993-999,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30670377,30370286)~~

摘　　要：线虫和蚯蚓是农业中广泛存在的土壤动物,由于它们与微生物的相互作用及对土壤生态系统能量传递和养分转化的影响,可能影响土壤微量气体代谢和温室气体的排放。通过在不同土壤线虫密度下接种蚯蚓的15d培养试验结果表明,土壤动物对土壤微量气体(CO2和N2O)代谢有显著促进作用。与灭线土相比,高密度线虫土壤处理与高密度线虫土壤加蚯蚓的处理导致CO2排放量分别增加了4.3倍和5.2倍,相应的N2O排放量增加了1.8倍和2.7倍。与低密度线虫土壤处理比较时,高密度线虫土壤处理导致CO2和N2O排放量分别增加了19%和21%。接种蚯蚓在高密度线虫土中较接种在低密度线虫土壤中的CO2和N2O排放量分别增加了12%和27%。5个处理中,除了低密度线虫加蚯蚓的处理和高密度线虫处理间差异不显著外,其余各处理间均达到极显著差异(P<0.01)。两种气体的排放速率呈极显著正相关(R2=0.9414)。高密度线虫土壤较低密度线虫土壤显著提高了土壤的DOC含量,不同线虫密度土壤中DOC显著性的差异与CO2和N2O排放密切相关(P<0.05)。Soil fauna e.g.nematode and earthworm,occur commonly in agricultural soil,may affect the greenhouse gas fluxes by both direct and indirect effects on organic-matter decomposition,nutrient cycling and the diversity and structure of microbiota in soil.We prepared soil with greater populations of bacterial-feeding nematodes,compared to a nematode-killed soil,to determine the effects of bacterial-feeding nematodes and earthworms on greenhouse gases emissions.Laboratory incubations were carried out for a period of 15 days.Carbon dioxide and nitrous oxide concentration were simultaneously analyzed with a modified gas chromatograph equipped with two detectors of FID and ECD.Soil with greater population nematodes and earthworms enhanced CO2 and N2O emissions.Cumulative emissions of the two gas fluxes in the greater population nematodes treatment and the greater population nematodes with earthworms treatment increased by 4.3 times and 5.2 times for CO2,1.8 times and 2.7 times for N2O,respectively versus the nematode-killed treatment.The emission fluxes of CO2 and N2O in soil with greater nematode populations were 19% and 21% higher than that of soil with smaller population of nematodes,inoculation of earthworms in greater population nematodes resulted in 12% and 27% more emission of CO2 and N2O than earthworms in smaller population nematodes.There are significant differences between each treatment except in soil with smaller population nematodes inoculated earthworms and soil with greater populations of nematodes.The two gas fluxes were significantly correlated（R2=0.9414;p〈0.01）.The greater population nematodes increased DOC value when compared with the smaller populations nematodes.Cumulative emissions of CO2 and N2O from the soils treated with different population nematodes were positively correlated with DOC concentration measured at the start of gas sampling（p 〈 0.05）.

关 键 词：温室气体排放 蚯蚓 食细菌线虫 相互作用 

分 类 号：S154[农业科学—土壤学] Q14[农业科学—农业基础科学]