真菌及细菌对毛竹及阔叶林土壤氧化亚氮排放的贡献  

Fungal and bacterial contribution to soil N_2O production in Phyllostachys edulis and broadleaf forest ecosystems

作　　者：李波成 邬奇峰[3] 张金林[1,2] 钱马 秦华[1,2] 徐秋芳[1,2] 

机构地区：[1]浙江农林大学环境与资源学院,浙江临安311300 [2]浙江农林大学浙江省森林生态系统碳循环与固碳减排重点实验室,浙江临安311300 [3]浙江省临安市农业技术推广中心,浙江临安311300

出　　处：《浙江农林大学学报》2014年第6期919-925,共7页Journal of Zhejiang A&F University

基　　金：国家自然科学基金资助项目(41271274);国家大学生科技创新项目(201210341010)

摘　　要：为研究真菌及细菌对毛竹Phyllostachys edulis林和阔叶林土壤氧化亚氮排放的贡献率,评估阔叶林演替为毛竹林对温室气体排放的影响,野外调查毛竹及阔叶林样地,每种林分选取4个样地采集土样,测定土壤理化性质及磷脂脂肪酸摩尔质量浓度,并进行室内抗生素抑制培养试验.试验设置4个处理：①不添加抗生素的对照;②仅添加放线菌酮;③仅添加链霉素;④同时添加放线菌酮和链霉素.培养7h后,测定氧化亚氮排放通量.结果表明：土壤真菌生物量与有机质极显著正相关（R^2=0.965,P＜0.01）,而与pH值显著负相关（R^2=-0.752,P＜0.05）.毛竹林和阔叶林土壤氧化亚氮排放通量没有显著差异.2种林地土壤中,真菌都是氧化亚氮排放的主要贡献者（毛竹林40.8％～56.2％,阔叶林38.0％～62.8％）,其贡献率显著高于细菌（毛竹林9.0％～33.4％,阔叶林12.6％～32.4％）.阔叶林演替为毛竹林对土壤真菌及细菌的氧化亚氮排放相对贡献率没有影响.相关分析结果表明：真菌及细菌氧化亚氮排放具有显著的同步效应（P＜0.01）,但与其生物量没有显著相关关系.To determine the relative contribution of fungi and bacteria to soil N2O production in Phyllostachys edulis and broadleaf forest ecosystems and to further study the impact of forest type on soil N2O emission when converting from a broadleaf forest to a Ph.edulis forest,an incubation experiment with soils collected from different forest types was conducted.Four broadleaf and Ph.edulis forest with similar topograph were selected randomly,and toplayer （0-20 cm） soils were sampled.Soil phospholipid fatty acids （PLFAs） were extracted and analyzed to measure the soil microbial biomass.To study the relative contribution of fungi and bacteria to soil N2O emissions,a selective inhibition experiment with addition of different antibiotics （streptomycin and/or cycloheximide,and an antibiotic-free control） was established using a random complete block design.Soil water content was adjusted to 90% water-filled pore space and N2O production was measured by gas chromatography after 7 h of incubation.Student＇s t-test and Pearson＇s correlation were used for statistical comparisons and correlation analyses,separately.Results indicated that fungal biomass was significantly and highly correlated with soil organic matter content （R^2 =0.965,P〈0.01） and significantly and negatively correlated with pH （R^2 =-0.752,P〈0.05）.No significant differences for N2O flux between Ph.edulis and a broadleaf forest were found.For the two forest types,fungi contributed significantly more （P〈0.05） to soil N2O fluxes （40.8%56.2% with Ph.edulis and 8.0%-62.8% for the broadleaf forest） than bacteria （9.0%-33.4% with Ph.edulis and 12.6%-32.4% in the broadleaf forest）.The correlation analyses showed that the fungi and bacteria for these two forest types had similar N2O flux patterns （P〈0.01）,but they were not correlated to biomass.Thus,the conversion of a broadleaf forest to Ph.edulis did not increase the N2O flux; denitrification activity of specific fungal species may also play a more important role in soil

关 键 词：森林土壤学 氧化亚氮 毛竹 阔叶林 真菌 

分 类 号：S714.3[农业科学—林学]