封育对高寒草甸植物群落构成及生态位特征的影响  

Effects of Enclosure on Plant Community Composition and Niche Characteristics in Alpine Meadow

作　　者：魏斌[1] 陆妮[1] 李佳琪[1] 赵敏[1] 于应文[1] 

机构地区：[1]兰州大学草地农业科技学院,草业科学国家级实验教学示范中心,兰州730020

出　　处：《西北植物学报》2017年第5期983-991,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金：兰州大学2017年国家级大学生创新创业训练计划(201710730103);国家重点研发计划(2016YFC0501902)

摘　　要：封育是天然草地管理的一种有效措施,利于草地生产力提高和退化草地恢复。该研究通过对青藏高原高寒草甸放牧和封育草地物种多样性、植被构成、植物种生态位特征、草地演替度等分析,解析高寒草甸植物种间关系及草地演替方向。结果表明:(1)封育显著降低了草地群落植物物种数以及α和β多样性指数,显著增加了草地1年生植物种数、地面芽植物种数和地上生物量。(2)放牧草地地上生物量以莎草科(59.7%)和禾本科(23.9%)为主,封育草地地上生物量以禾本科(85.0%)为主;放牧草地优势种为矮嵩草(Kobresia humilis)和线叶嵩草(K.capillifolia),封育草地优势种为垂穗披碱草(Elymus nutans)和早熟禾(Poasp.)。(3)放牧和封育草地的群落植物种重要值均与各自的生态位宽度变化规律一致。(4)草地植物种间竞争主要发生在不同科属植物种之间,封育增加了群落植物种整体生态位重叠值和植物种间竞争。(5)草地群落演替度为封育地>放牧地,封育群落处于较稳定状态。研究认为,封育促进了高寒草甸由莎草+杂类草群落向禾草+杂类草群落演替。Enclosure is one effective management method of native grassland,which is benefit for the improvement of grassland productivity and restoration of degraded grassland.We studied the species diversity,vegetation composition,plant species niche characteristics and grassland succession degree of grazing and enclosure grasslands in an alpine meadow on the Qinghai-Tibet Plateau,and analyzed the plant interspecific relationship and the direction of succession of alpine meadow.The results showed that：（1）the enclosure significantly decreased number of species,andαandβdiversity indexes of grassland community,but significantly increased the number of species of therophyte and hemicryptophyte,and aboveground biomass.（2）For the aboveground biomass ratio,grazing grassland dominated by Cyperaceae（59.7%）and Gramineae（23.9%）,while the enclosure grassland dominated by Gramineae（85.0%）.For the dominant species,grazing grassland was Kobresia humilis and K.capillifolia,while for the enclosure grassland,itwas Elymus nutans and Poasp.（3）The pattern of importance value of plant species accorded with their respective niche breadth values.（4）The interspecific competition of grazing and enclosure grassland mainly exhibited between the species of different families or genera.The enclosure increased their overall niche overlap values and interspecific competition.（5）The succession degree of plant community was enclosure grassland grazing grassland,and the enclosure community was in a relative stable state.The research indicated that the enclosure management can encourage the alpine meadow succession from sedges/forb community to grass/forb community.

关 键 词：封育 物种多样性 生活型 生物量构成 生态位宽度 生态位重叠值 草地演替 

分 类 号：Q948.1[生物学—植物学]