摘要
近年来小叶章(Deyeuxia angustifolia(Kom.)Y.L.Chang)等草本植物入侵长白山西坡苔原带,改变了原来以灌木为优势种的原生植被群落物种组成,进而影响到土壤微生物群落结构和土壤养分.为此,在长白山西坡苔原带设立了8个长期观测样地,通过对群落重要值、土壤微生物磷脂脂肪酸(PLFA)和土壤养分含量等进行测定、分析,揭示了近7年来长白山西坡苔原植物-土壤相互作用过程.结果表明:2011—2017年间,以小叶章、藜芦(Veratrum nigrum Linn.)为代表的多种草本植物重要值上升,原生优势种灌木植物牛皮杜鹃(Rhododendron aureum Georgi)与笃斯越桔(Vaccinium uliginosum Linn.)的重要值减小;土壤微生物总量随入侵程度的加重而持续增加,增幅为细菌>放线菌>真菌;除全磷外,土壤养分随微生物PLFA总量的增多而明显减少.草本植物入侵导致土壤养分减少,可能会抑制草本植物的入侵,长白山西坡苔原通过植被—土壤微生物—土壤养分之间的负反馈,实现了自我稳定.
Changes of vegetation species and community structure will lead to the change of soil microbes and enzyme activity,and the soil fertility will change accordingly.While the change of nutrients will affect growth of vegetation,which affects soil microbes conversely.Changbai Mountain has undergone remarkable changes in species composition of the tundra vegetation community.Encroachment of herbaceous plants represented by Deyeuxia angustifolia(Kom.)Y.L.Chang changed the original vegetation communities whose dominant species were Rhododendron aureum Georgi and Vaccinium uliginosum Linn.The change of dominant species composition,which in turn affects the soil microbial community structure,changed the soil fertility.Based on the monitoring of tundra vegetation and soil in west slope of Changbai Mountain in recent 7 years,the results indicated that:the herb invasion represented by Deyeuxia angustifolia(Kom.)Y.L.Chang led to changes in the dominant species composition of the tundra vegetation on the west slope of Changbai Mountain.6 herbaceous plants and 2 shrub plants were identified as dominant species based on the importance value(IV)of vegetation community.The encroachment process of herbaceous plants in recent 7 years could be divided into 3 phases(mild invasion stage,moderate invasion stage and stable invasion stage)according to annual changes of IV of dominant vegetation community:in mild invasion phase,IV of 2 herb plants increased significantly(Deyeuxia angustifolia(Kom.)Y.L.Chang,Veratrum nigrum Linn.)while IV of 2 shrub plants stayed stable;In moderate invasion phase,IV of 3 herb plants increased significantly while the other 3 herb plants kept stable,with IV of 2 shrub plants both decreased sharply;In stable invasion phase,almost all plants entered into stable phase except for Veratrum nigrum Linn.and Deyeuxia angustifolia(Kom.)Y.L.Chang which increased again;Changes of vegetation resulted in an increase in soil microbes and principal components analysis indicated that the increase range was different among different microbe species,which was bacteria>fungi>actinomycetes.Redundancy analysis and bivariate correlation analysis showed that significant negative correlation existed between soil nutrients(total phosphorus not included)and soil microbes.Deduced that increase of soil microorganisms resulted in the acceleration of decomposition of organic matter so that the soil fertility decreased sharply.Unlike previous studies,available nutrients also declined in our study.Invasion of herbaceous plants leads to a decrease in alpine tundra soil nutrients,thereby inhibiting the invasion of herbaceous plants conversely.The alpine tundra on Changbai Mountain achieves self-stability through negative feedback in vegetation-soil microbes-soil nutrients system.
作者
胡睿
张英洁
靳英华
许嘉巍
陶岩
贺红士
高翔
韩莹莹
王慧赟
白云玉
HU Rui;ZHANG Ying-jie;JIN Ying-hua;XU Jia-wei;TAO Yan;HE Hong-shi;GAO Xiang;HAN Ying-ying;WANG Hui-yun;BAI Yun-yu(School of Geographical Sciences,Northeast Normal University,Changchun 130024,China)
出处
《东北师大学报（自然科学版）》
CAS
北大核心
2020年第2期115-123,共9页
Journal of Northeast Normal University(Natural Science Edition)
基金
国家自然科学基金资助项目(41571078,41171072)
长白山地理过程与生态安全教育部重点实验室资助项目.
关键词
草本入侵
长白山苔原
重要值
PLFA
土壤养分
herb encroachment
Changbai Mountain alpine tundra
importance value
PLFA
soil nutrient
