引进种桉树人工林取代天然次生林对土壤微生物群落结构和功能的影响  

Impacts of converting natural secondary forests to exotic Eucalyptus plantations on structure and function of soil microbial communities

作　　者：陈法霖 张凯[3] 王芸[4] 吴爱平 李有志 邹冬生 郑华 CHEN Falin;ZHANG Kai;WANG Yun;WU Aiping;LI Youzhi;ZOU Dongshengi;ZHENG Hua(Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area,College of Bioscience and Biotechnology,Hunan Agricultural University,Changsha 410128,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Belting 100085,China;College of Grassland and Environment Sciences,Xinjiang Agricultural University,Urumqi 830052,China;Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection,College of Resources and Environment,Linyi University,Linyi 276005,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]湖南农业大学生物科学技术学院洞庭湖区农村生态系统健康湖南省重点实验室,长沙410128 [2]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [3]新疆农业大学草业与环境科学学院,乌鲁木齐830052 [4]山东省水土保持与环境保育研究所,临沂大学资源与环境学院,临沂276005 [5]中国科学院大学,北京100049

出　　处：《生态学报》2018年第22期8070-8079,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41501325,41761067,41401329).

摘　　要：由于桉树对原生生态系统具有潜在的破坏性影响,随着桉树人工林面积的不断扩大,桉树种植对森林生态系统的影响越来越受到社会的关注。围绕引进种桉树造林对土壤微生物群落的影响,应用成对试验设计,采用磷脂脂肪酸(PLFA)和BIOLOG微平板培养等技术手段探讨土壤微生物群落结构和功能如何响应桉树人工林取代天然次生林这一变化,主要结果为:桉树人工林取代天然次生林导致:(1)土壤微生物生物量减少,包括:生物量碳、氮和磷脂脂肪酸丰度显著下降;(2)反映土壤微生物群落生理胁迫状况的指标:饱和直链脂肪酸/单不饱和脂肪酸、革兰氏阳性菌/革兰氏阴性菌、支链异构/反异构脂肪酸以及cy19:0/18:1ω7c的比值显著增加;(3)土壤微生物群落碳代谢强度和多样性显著降低;(4)桉树人工林取代天然次生林导致土壤微生物群落结构变化和功能退化的主要环境因素包括:植物物种丰富度和覆盖度的降低以及土壤资源(碳、氮和水分)可获得性的降低。综上所述,引进种桉树人工林取代天然次生林降低了植物物种丰富度和覆盖度以及土壤资源的可获得性,进而显著增强了土壤微生物群落生理胁迫、显著降低了土壤微生物群落功能。Extensive afforestation with exotic species has caused broad concern due to its potential impacts on ecosystems.Eucalyptus is one of the main introduced tree species in China.Understanding the impacts of afforestation with Eucalyptus on the structure and function of soil microbial communities plays a key role elucidating the impacts of a single species on ecosystem services and implementing the scientifc management in Eucalyptus plantations.Paired comparison (i.e.natural secondary forests and Eucalyptus plantations)test was used to evaluate how the soil microbial structure and function respond to land use change from natural secondary forests to exotic Eucalyptus plantations in Baisha County,Hainan Province, southern China.The soil microbial communities were evaluated by comparing the biomass,phospholipid fatty acid (PLFA) composition,and carbon metabolic function (BIOLOG profiles).Compared with those in natural secondary forests,the size of soil microbial communities in Eucalyptus plantations significantly decreased.The mean value of soil microbial biomass carbon in Eucalyptus plantations was 376.65mg/kg,but it was 631.86mg/kg in natural secondary forests.The mean values of soil microbial biomass nitrogen in Eucalyptus plantations and natural secondary forests were 61.91mg/kg and 94.72mg/ kg,respectively.The soil microbial biomass in Eucalyptus plantations was significantly lower than that in natural secondary forests.Additionally,Eucalyptus plantations had significantly lower abundances of gram-positive bacterial,gram-negative bacterial,arbuscular mycorrhizal fungal,fungal,actinomycetic,and total phospholipid fatty acids than the natural secondary forests.Forest conversion from natural secondary forests to Eucalyptus plantations resulted in an increase in soil microbial physiological stress,and a decrease in soil microbial function.The indicators denoting stress related to soil nutrient levels,the ratios of monounsaturated to saturated fatty acids,gram-positive to gram-negative bacteria,iso-to anteiso-branched

关 键 词：桉树人工林 天然次生林 土壤微生物群落 PLFA BIOLOG 

分 类 号：S714.3[农业科学—林学] S792.39