摘要
通过为期5年的野外试验,包括6个氮添加量(年氮添加量分别为0、5、10、15、20、50 g m^(-2)a^(-1)),每月进行1次氮添加处理,每个实验处理重复10次,基于物种有无和地上生物量两类数据,分析氮添加对内蒙古草原植物群落的影响.结果显示:内蒙古草原植物群落存在非随机的组配规则,存在4组四物种优势组合.氮添加量的增加会削弱组配过程中确定性驱动力,物种优势组合在氮添加量50 g m^(-2)a^(-1)下最弱.氮添加量对群落组成有显著影响,氮添加量与群落的第一主成分和第二主成分均在0.05水平上显著正相关,相关系数分别是0.367和0.436.随着氮添加量的增加,基于Spearman相关系数的物种互作用网络的节点数(物种丰富度)和连接数(物种互作用数)减少,网络的拓扑结构越来越松散.植物群落耦合性(物种互作用的均值)在氮添加量20 g m^(-2)a^(-1)及以下始终保持在0.7以上.本研究表明氮沉降的增加会弱化植物群落的组配规则,减弱物种互作用,因此必须加强草原氮沉降管理,控制草原氮沉降浓度.(图3表3参44附表1)
To assess the effects of nitrogen deposition on a plant community,we analyzed the co-occurrence and biomass data of plants based on a five-year simulation nitrogen deposition experiment in the grasslands of Inner Mongolia,China.Six gradients of nitrogen deposition were applied,including 0,5,10,15,20,and 50 g m^(-2)a^(-1).Each treatment was repeated 10 times.The results showed the following:(1)There were non-random assembly rules;and four dominant four-species combinations;(2)A chi-square test showed that four dominant four-species combinations weakened as an increased rate of nitrogen was added,and the combinations were weakest when a rate of 50 g m^(-2)a^(-1) nitrogen was added;(3)A pearson correlation analysis showed that the rate of nitrogen added significantly correlated with the first and second principal components of the community(r_(1)=0.367,r_(2)=0.436,P<0.05).In addition,an Analysis of similarities(ANOSIM)showed that there were significant differences among the communitieswhen different rates of nitrogen were added(P=0.0001);(4)The number of species and links in these species interaction network decreased when higher rates of nitrogen were added,and the topology structure of network became simpler;(5)The community coupling(the mean value of species interaction)remained at a high level when the amount of nitrogen added≤20 g m^(-2)a^(-1).The conclusion of this study is that the depositon of high levels of nitrogen weakens the assembly rules and ruins the interaction between species.Therefore,we should focus on controlling the concentration of nitrogen during the management of grasslands in the future.
作者
王珊
孙晴晴
杨俊杰
张光明
李金山
WANG Shan;SUN Qingqing;YANG Junjie;ZHANG Guangming;LI Jinshan(College of Science,Beijing Forestry University,Beijing 100083,China;State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2022年第3期712-719,共8页
Chinese Journal of Applied and Environmental Biology
基金
国家重点研发计划项目(2016YFC0500705)
中央高校基本科研业务费专项资金项目(2015ZCQ-LY-01)资助。
关键词
氮沉降
组配规则
物种互作用
群落组成
内蒙古草原
nitrogen deposition
assembly rule
species interaction
community composition
Inner Mongolia grassland
