小叶锦鸡儿(Caragana microphylla)灌丛对草本群落特征的影响  

Effects of Caragana microphylla on herbaceous community characteristics

作　　者：张敬敏 珠娜 蔡育蓉 王储 刘嘉慧 李乐 罗玉红 徐大伟[1] 闫玉春[1] ZHANG Jingmin;ZHU Na;CAI Yurong;WANG Chu;LIU Jiahui;LI Le;LUO Yuhong;XU Dawei;YAN Yuchun(Instiute of Agricultural Resoures and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《生态学报》2023年第21期8830-8839,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(42071070,32230065);中国农业科学院中央级公益性科研院所基本科研业务费专项资金资助项目(G2022-01-442021)。

摘　　要：基于干旱、半干旱草原灌丛化现象的发展,探究灌木与草本之间的关系对深刻理解灌丛化对草原植物群落特征的影响机制具有重要意义。然而,很少有研究考虑草地类型和灌丛斑块大小对灌木和草本植物之间关系的影响。在内蒙古典型草原和荒漠草原的自由放牧草地上选择了18个小叶锦鸡儿灌丛化样地进行野外采样,并调查了不同大小灌丛和周围草地的植物群落特征。运用单因素方差分析(one-way ANOVA)和最小显著差异法(LSD)来检验不同大小灌丛斑块内外的植被群落特征(高度、密度、地上生物量、凋落物量)和植物多样性指数(Shannon-Wiener指数、Pielou指数、丰富度指数、群落Sprensen相似性系数)的差异性。结果表明:(1)与草地相比,两种草原类型的灌丛产生、捕获了更多的凋落物,灌丛的保育作用显著提高了斑块内草本植物的高度,但灌丛占用了生存空间和资源,从而降低了斑块内草本植物的密度和地上生物量。(2)灌丛对多年生草本植物的地上生物量有明显的抑制作用,但对两种草原类型的一、二年生草本植物没有显著影响(典型草原中的小灌丛除外)。(3)两种草原类型的灌丛对草本植物多样性的影响存在差异。典型草原灌丛内多样性指数和丰富度指数低于灌丛外,均匀度指数无显著变化,灌丛斑块增大对草本植物物种丰富度产生了负面影响;在资源相对匮乏的荒漠草原区,灌丛并没有改变草本植物多样性指数,但降低了草本植物物种丰富度,并且大灌丛斑块内草本植物的均匀度指数降低。(4)灌丛与草地斑块的群落相似性随灌丛斑块增大呈指数下降趋势,小灌丛斑块和草地斑块之间的群落相似性在两种草原类型中最高。本研究表明灌丛对草本植物既有保育作用,又存在竞争作用,同时这些作用受到草地类型和斑块大小的影响。这对预测和调控灌丛侵占草地植物群落Based on the development of shrub encroachment in arid and semi-arid grasslands,exploring the relationship between shrubs and herbs has important significance to deeply understand the mechanism of effects of shrub encroachment on grassland plant community characteristics.However,relatively few studies consider the effect grassland types and shrub patch size on the relationship between shrubs and herbs.We selected 18 sites with shrub-encroached of Caragana microphylla for field sampling in free grazing grasslands in typical steppe and desert steppe of Inner Mongolia,and investigated the plant community characteristics of different sizes of shrubs and adjacent interspaces.One-way analysis of variance(one-way ANOVA)and Least Significant Difference(LSD)were used to test the differences in plant community characteristics(height,density,aboveground biomass,litter mass)and plant diversity indexes(Shannon-Wiener index,Pielou index,richness index,community Sprensen similarity coefficient)inside and outside shrub patches with different sizes.The results were as follows.(1)Compared with interspace,the shrubs both in two grassland types produced and captured more litter and the height of herbaceous plants in the shrub patch was significantly increased by facilitation of shrub,but shrub occupied the living space and resources,which reduced the density and aboveground biomass of herbaceous plants in the patch.(2)Shrubs had obvious inhibitory effects on the aboveground biomass of perennial herbs,but had no significant effect on annual and biennial herbs in two grassland types(except for small shrubs in typical steppe).(3)There are differences in the effects of shrubs on herbaceous plant diversity in two grassland types.The diversity index and richness index in the shrubs in typical steppe were lower than those outside the shrubs,the evenness index did not change significantly,and the expansion of shrub patch had a negative impact on the richness of herb species.In desert steppe,with relatively scarce resources,shrubs did not ch

关 键 词：干旱、半干旱草原 灌丛化 草地类型 斑块大小 物种多样性 地上生物量 

分 类 号：Q948[生物学—植物学]