亚高寒草甸群落结构决定群落生产力实例验证  

Case verification of community structure determining community productivity in subalpine meadow

作　　者：李伟[1] 张荣[1] LI Wei;ZHANG Rong(State Key Laboratory of Grassland Agroecosystems,College of Ecology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学生态学院,草地农业生态系统国家重点实验室,兰州730000

出　　处：《植物生态学报》2023年第5期713-723,共11页Chinese Journal of Plant Ecology

摘　　要：在植物物种丰富度与生产力之间关系的研究中,多以物种丰富度和生产力作为双变量,常常忽略在同一物种丰富度水平下可能影响群落生产力的其他因素,例如物种组合与组成等。该研究采用盆栽法,以中华羊茅(Festuca sinensis)、垂穗披碱草(Elymus nutans)、鸭茅(Dactylis glomerata)和紫花苜蓿(Medicago sativa)为研究对象,设置4个物种丰富度水平(1、2、3、4),并在最高物种丰富度水平下,保持总种植密度不变,改变各组成物种的相对比例(10%、20%、30%、40%),探讨群落物种组合、组成及物种所属功能群对群落生产力的影响。结果表明:1)在较低物种丰富度下,群落生产力随物种丰富度增加而增加,在较高物种丰富度下,群落生产力随物种丰富度的增加不再显著变化。2)群落物种组合及组成对群落生产力具有显著影响,配置垂穗披碱草的群落及垂穗披碱草占比大的群落具有更高生产力。3)混播物种所属功能群对群落生产力具有显著影响,豆科植物对其他混播物种生产力表现出促进或抑制作用,禾本科物种垂穗披碱草对群落生产力有正效应,中华羊茅和鸭茅对群落生产力影响不明显。由此推测,物种丰富度与生产力之间存在一定的表观关系,植物群落生产力更取决于与物种丰富度相关的物种组合及其组成,而非物种丰富度。Aims In studies on the relationship between plant species richness and productivity,species richness is regarded primarily as an independent variable and productivity as a response variable,whereas other factors that may affect community productivity at the same species richness levels,such as species combination and composition,are largely ignored.The objectives of this research have been determined:(1)the effect of community structure on community productivity,including species combination,composition,and functional groups to which the species belongs,and(2)the relationship between species richness and community productivity in subalpine meadow communities.Methods In the pot experiment,seeds of four plant species(Festuca sinensis,Elymus nutans,Medicago sativa and Dactylis glomerata)were sown to pots in terms of given species combination and composition at varying levels of species richness(1,2,3,4).In both monocultures and mixtures,the overall planting density of the community was 100.Seeds were sown in equal numbers to pots in communities of diverse species combinations at various levels of species richness.The species composition of four-species mixed-seeding communities was designed as 10%,20%,30%,and 40%density proportions,respectively.Each treatment had five replicates,and weeds were manually removed on a regular basis.The above-ground biomass in each pot had been harvested,dried,and measured by species at the end of September.Important findings Community productivity increased with increasing species richness at lower species richness,but not substantially at higher species richness,The combination and composition of community species had a significant effect on community productivity,with the mixed-seeding community containing Elymus nutans and communities with a high proportion of Elymus nutans having higher productivity.Among the functional groups to which the species belonged,legumes either promoted or inhibited the production of other species.Elymus nutans enhanced community productivity,whereas Fest

关 键 词：植物功能群 物种丰富度 群落生产力 群落生态学 亚高寒草甸 

分 类 号：S812[农业科学—草业科学]