若尔盖高原湿地不同生境下植被类型及其分布规律

The Vegetation Type and Its Distribution Regularity under Different Habitats in Ruoergai Plateau

采用野外调查方法研究了若尔盖高原湿地不同生境下的植被类型及其分布规律。结果表明,随着湿地水分由多到少的变化,植物群落类型发生相应的生态演替,其演替序列为水生植被→沼生植被→沼泽化草甸植被→草甸植被,且在水平方向呈对列式(牛轭湖或小溪两岸)和同心圆式(洼地周围)分布;从湖心至丘顶的垂直分布规律表现为水生植被→沼泽植被→沼泽化草甸→亚高山草甸→亚高山灌丛。沼生植物群落的种类相对较少并有呈单优势种分布的趋势,湿生或中生植物群落的种类逐步增多,并表现出具多优势种和建群种的分布格局。随着湿地水分的恢复和增加,湿地生态系统的初级生产力提高。3种典型植物群落的活体生物量及总生物量大小顺序为乌拉苔草(Carex meyeriana)群落>木里苔草(Caremuliensis)-花葶驴蹄草(Caltha scaposa)群落>藏嵩草(Kobresia tibetica)-无脉苔草(Carex ennrvis)群落。湿地水分条件是影响湿地生态系统初级生产力的决定因素。

The vegetation type and its distribution regularity under different habitat with field investigation in Ruoergai Plateau were studied.The results indicated that there was an ecological succession of wetland plant communities and that the successive series is as follows:aquatic plant → helophytes → swampy prata → herbosa with the changes of habitat from aquatic to mesophytic. The horizonal distribution regularity of plant communities showed symmetric distribution at loop lake or banks of small stream and concentric distribution at depression.The vertical distribution regularity is as follows: aquatic vegetation → moor vegetation → swampy prata vegetation → subalpine meadow → subalpine shrub from the center of lake to the hilltop. There were fewer species of helophytes and single species dominancy community was found in helophytes community;the quantity of plant species increased gradually and poly dominant species or edificator were found in hygrophytes or mesophyte community. With the increase of wetland water,the primary production of wetland ecosystem increased,the order of biomass of living plant being Carex meyeriana co.>Carex muliensis-Caltha scaposa co.>Kobresia tibetica-Carex ennrvis co. in three typical wetland plant communities,so was the total biomass. It was shown that wetland water was a key factor affecting primary production in wetland ecosystem.