少花蒺藜草入侵与干旱对羊草群落生产力的影响机制  

Mechanisms of the invasion of Cenchrus spinifex and drought effects on productivity of Leymus chinensis community

作　　者：白皓然 侯盟 刘艳杰 BAI Hao-Ran;HOU Meng;LIU Yan-Jie(Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院东北地理与农业生态研究所,长春130102 [2]中国科学院大学,北京100049

出　　处：《植物生态学报》2024年第5期577-589,共13页Chinese Journal of Plant Ecology

基　　金：中国科学院率先行动青年人才项目(Y9B7041001)。

摘　　要：羊草(Leymuschinensis)草原是中国草地资源中珍贵的自然财富,其生产力受到多种全球变化因素的制约。其中,少花蒺藜草(Cenchrusspinifex)入侵(以下简称为“入侵”)与干旱对东北松嫩草原区羊草群落影响尤为显著,但相关机制仍较少被关注。该研究通过微宇宙控制实验,采用两因素完全交互设计,探究入侵与干旱对羊草群落生产力影响的作用机制。因素一是入侵处理(入侵vs对照),因素二为水分处理(干旱vs正常水分),每个处理设置10次重复,实验共计40盆。结果表明:入侵与干旱会显著降低羊草群落与优势物种羊草的地上生物量。干旱处理下土壤有效氮含量与土壤节肢动物的丰富度显著下降,而土壤细菌与球囊霉科(Glomeraceae)丛枝菌根真菌(AMF)丰度显著增加。入侵对土壤真菌有效物种数的影响受到干旱的调节,表现为在正常水分条件下入侵不影响土壤真菌的有效物种数,但在干旱条件下入侵显著增加土壤真菌的有效物种数。结构方程模型结果表明,入侵与干旱均直接抑制羊草群落生产力。干旱通过增加土壤真菌优势菌群的丰度进而间接缓解对本地群落生产力的负面影响。此外,两者协同作用通过增加土壤真菌群落多样性抑制群落生产力。该研究为将来更好地维护草地生产力,保护优质牧草提供理论依据。Aims The Leymus chinensis community is one of the most precious natural wealth in China’s grassland resources.However,its productivity is constrained by a variety of global change factors.Although,the invasion of Cenchrus spinifex(hereafter as“invasion”)and drought are two of most important global change factors that significantly affected the productivity of L.chinensis community in the northeast Songnen grassland area,the relevant mechanisms have still not sufficient attention.Methods Through the microcosmic control experiments and a complete interaction design with two factors,we explored the mechanism of invasion and drought on the productivity of the L.chinensis community.Factor one was the invasion treatment(invasion vs control),factor two was the water treatment(drought vs normal water),and a total of 10 replications were set up under each treatment,with a total of 40 pots in the experiment.Important findings The results showed that invasion and drought significantly reduced the aboveground biomass of the L.chinensis community and the dominant species L.chinensis.Soil available nitrogen content and soil arthropod richness significantly decreased under drought treatment,while soil bacterial abundance and arbuscular mycorrhiza fungi(AMF)of the family Glomeraceae increased significantly.The effect of invasion on the effective number of species of soil fungi is moderated by drought,showed that invasion did not affect the effective number of species of soil fungi under normal water conditions,but significantly increased the effective number of species of soil fungi under drought conditions.The results of the structural equation modeling indicated that invasion and drought directly suppressed the L.chinensis community productivity.Drought has indirectly mitigate negative effect on native community productivity by increasing the abundance of dominant soil fungi.In addition,the interaction of invasion and drought suppressed native community productivity by increasing soil fungal community diversity.This stud

关 键 词：少花蒺藜草 干旱 草地生产力 羊草群落 植物入侵 

分 类 号：S812[农业科学—草业科学]