大伙房水库流域水源涵养林植被类型对土壤NH4+-N和NO3--N淋溶的影响

生态学杂志ChineseJournalofEcology2017，36(8)：2103—2110DOI：10．13292／j．1000—4890．201708．025大伙房水库流域水源涵养林植被类型对土壤NH4+-N和NO3一-N淋溶的影响胡亚林刘杰范志平”涂志华卢聪刘建治(福建农林大学林学院，福州350002；辽宁老秃顶子国家级自然保护区抚顺管理局，辽宁抚顺113208；。辽宁石油化工大学生态环境研究院，辽宁抚顺113001)摘要流域内植被类型是土壤氮素淋溶迁移的重要影响因子，降雨丰水季节不同植被类型土壤氮素淋溶是量化评价流域土壤氮素流失和水质变化的关键。本研究采用离子交换树脂袋法分析降雨丰水期槭树一蒙古栎林、落叶松人工林和山杨林3种植被类型土壤NH一N和NO3一-N淋溶季节动态特征。结果发现，降雨丰水期(7—9月)不同植被类型土壤无机氮含量(NH4+-N和NO一一N)动态变化差异显著(P<0．05)，NH4+-N在无机N中占73．4％一93．3％，槭树一蒙古栎林、山杨林NO一-N含量7月份最大，而落叶松人工林NO一-N含量8月份最大；土壤氮素淋溶的主要成分是NO3--N，落叶松人工林土壤氮潜在性淋溶高于槭树-蒙古栎林和山杨林；土壤微生物生物量碳(MBC)和氮(MBN)随着土层加深逐渐减小，阔叶林MBC和MBN显著大于落叶松人工林；土壤N淋溶量与MBN呈显著负相关，证明土壤微生物N固持作用能减少N淋溶流失。据此结果，建议在该流域开展水源涵养林建设中应加强河岸带天然林保护和促进人工水源涵养林转变为天然次生林。关键词植被类型；水源涵养林；铵态氮；硝态氮；N淋溶EfectsofvegetationtypeofwaterconservationforestsonsoilNHd-NandNO一-Nlea-chinginDahuofangwatershed．HUYa-lin，LIUJie，FANZhi—ping”，TUZhi—hua，LUCong，LIUJian-zhi(CollegeofForestry，FujianAgricultureandForestryUniversity，Fuzhou350002．ChinaFushunAuthorityofLiaoningLaotudingziNationalNatureReserve，Fushun113208，Liaoning，C^ina；InstituteofEco—environmentalSciences，LiaoningShihuaUniversity，nhun113001。Liaoning．Cina)．Abstract：Vegetationtypesplayanimportantroleincontrollingsoilnitrogen(N)leachingthatisakeyindicatorofsoilNlossandwatereutrophicationinawatershed．Inthisstudy．wemeas．uredsoilNHd一NandNO，一．Nlcachingusingion．exchangeresinbagsmethodinAcermono—Quercusmongolica．rixgmeliniiandPopulusdavidianawaterconservationforestsintheDahuofangwatershed．OurresultsshowedthatsoilNHd一NandNO一．Nconcentrationsweresig．nificantlydifferentunderdifferentvegetationsduringtheprecipitationabundantseasonfromJulytoSeptember．SoilNHNaccountedfor73．40％一93-30％ofsoiltotalinorganicN．InJuly，soilNO一．NconcentrationwasthehighestinA．mono—Q．mongolicaandP．davidianaforests．whilesoilNO一一NcontentinL．gmeliniiplantationwasthehighestinAugust．NO一一NisthemainformofsoilNunderlcachingloss．andsoilNlosswashigherinL．gmeliniiplantationcomparedtoA．morro—Q．mongolicaandP．davidianaforests．Soilmicrobialbiomasscarbon(MBC)andnitrogen(MBN)decreasedgraduallywithincreas