天然林转人工林对亚热带森林土壤团聚体中亚硝酸盐还原基因丰度的影响  

Effects of conversion of natural forest to plantations on the abundance of nitrite reducing genes in soil aggregates in subtropical forest region

作　　者：邓米林 叶桂萍 胥超[2,4] 宛颂 贺纪正 林永新 DENG Mi-lin;YE Gui-ping;XU Chao;WAN Song;HE Ji-zheng;LIN Yong-xin(Cultivation Base of State Key Laboratory for Subtropical Mountain Ecology,Fuzhou 350007,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China;Institute of Oceanography,Minjiang University,Fuzhou 350108,China;Fujian Sanming Forest Ecosystem and Global Change National Observation and Research Station,Sanming 365000,Fujian,China)

机构地区：[1]湿润亚热带山地生态国家重点实验室培育基地,福州350007 [2]福建师范大学地理科学学院,福州350007 [3]闽江学院海洋研究院,福州350108 [4]福建三明森林生态系统与全球变化国家野外科学观测研究站,福建三明365000

出　　处：《应用生态学报》2023年第1期25-30,共6页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(42077041);福建省自然科学基金项目(2020J01187)资助。

摘　　要：我国亚热带地区大面积天然林已转变为人工林,对森林生态系统结构和功能产生了极大影响。为揭示森林土壤团聚体中N_(2)O产生的关键基因亚硝酸盐还原基因(nirK和nirS)对森林转换后的响应特征,本研究选取中亚热带米槠天然林、杉木人工林和马尾松人工林为对象,分析了3种林分土壤和团聚体中nirK和nirS基因丰度。结果表明:天然林转变成人工林后,土壤pH值升高,但铵态氮含量下降。森林转换对土壤团聚体结构组成影响不大,但不同粒径团聚体中nirK和nirS基因丰度存在差异,以小团聚体分布最多,粉-黏颗粒分布最少。各林分土壤中nirK基因丰度均显著高于nirS基因丰度,表明nirK在酸性森林土壤中占主导。天然林转人工林显著增加全土和团聚体中nirK及nirS基因丰度,表明森林转换有利于提高nirK和nirS基因丰度,这可能与pH值的提高有关。综上,天然林转变为杉木或马尾松人工林显著提高了土壤和团聚体中nirK和nirS丰度,但对团聚体质量分数无显著影响。Large proportion of natural forest has been transformed into plantations in subtropical regions,with consequences on forest ecosystem structure and function.In order to understand the responses of two nitrite reducing genes(nirK and nirS)in N_(2)O production to forest conversion,we collected soil samples from Castanopsis carlesii natural forest,Cunninghamia lanceolata plantation and Pinus massoniana plantation and examined the abundance of nirK and nirS genes in soils and aggregates.Results showed that forest conversion increased soil pH,while decreased soil ammonium content.Forest conversion did not influence the mass proportion of soil aggregates.The abundance of nirK and nirS genes varied in aggregates with different particle sizes.The abundance of nirK and nirS genes was the highest in small macraoaggregates and the lowest in the silt-clay particles.Moreover,the abundance of nirK was significantly higher than that of nirS in soils of all forest types,indicating that nirK dominated in the acidic forest soils.Conversion of natural forest to plantations significantly increased the abundance of nirK and nirS genes in the bulk soil and aggregates,indicating that forest conversion would be beneficial for the growth of microorganisms bearing nirK and nirS genes,which might be associated with the increases of soil pH.Taken together,conversion of natural forest to C.lanceolata plantation or P.massoniana plantation significantly increased the abundance of nirK and nirS in soils and aggregates,but did not affect the mass proportions of aggregates.

关 键 词：森林转换 土壤团聚体 NIRK nirS 

分 类 号：S714.2[农业科学—林学]