【摘要】 通过对民勤地区3个治理基地的9种机械沙障样地和1个对照样地进行植被调查,研究机械沙障对荒漠草地结构和物种多样性的影响,探讨机械沙障与沙生植物间的相互作用。结果表明:(1)荒漠草地物种数量随着沙障设置以及治理年限的增加而逐渐增加(从2种增加到3～7种),植被结构由沙蓬(Agriophyllum squarrosum)优势种群向五星蒿(Bassia dasyphylla)优势种群演变,由一年生草本的单一型向一年生草本+多年生草本+灌木的复合型演变。(2)物种α多样性变化存在地域性与治理年限的差异,在该区域小尺度地理范围内由南向北呈递减趋势。而随着治理年限增加,物种丰富度、多样性指数均呈增加趋势,α多样性指数顺序为稻草秆网格沙障>尼龙网格沙障、建筑垃圾网格沙障、黏土行式沙障>小麦秆网格沙障、玉米秆行式沙障、葵花秆网格沙障、葵花秆行式沙障>玉米秆网格沙障>无沙障流沙地(CK)。(3)治理年限对物种β多样性影响有显著差异性,β指数为黏土行式沙障>葵花秆网格沙障、玉米秆网格沙障>稻草秆网格沙障、尼龙网格沙障>小麦秆网格沙障、葵花秆行式沙障、建筑垃圾网格沙障>玉米秆行式沙障>无沙障流沙地(CK)。群落共有度指数和群落相异性指数存在沙障材料的差异性,不同农作物秸秆沙障之间差异不显著,但与黏土行式沙障和尼龙网格沙障之间的差异显著(P<0.01)。更多还原

【Abstract】 This study conducted vegetation surveys on nine mechanical sand barrier plots and a control(CK) plot in 3 experimental bases in Minqin area. The impact of mechanical sand barrier on plant community structure and species diversity was studied in desert grassland, and the interaction between mechanical sand barrier and desert plants was also explored. The results showed that:(1) The number of species gradually increased with the increase of sand barriers and management duration(from 2 species to 3～7 species). The community structure evolved from the dominant population of Agriophyllum squarrosum to Bassia dasyphyll. The lifestyle of plant species evolved from the single type of annual herb to the mixed type characterized by annual herb, perennial herb and shrub.(2) The change of species α diversity had regional and management duration differences, which showed a decreasing trend from south to north in the small-scale of geographic range of the region. With the increase of management duration, the species richness and diversity index exhibited an increasing trend. The rank of species α diversity affected by sand barrier was showing as follows: rice straw grid sand barrier > nylon grid sand barrier, construction waste grid sand barrier, and clay line sand barrier > wheat straw grid sand barrier, corn straw line sand barrier, sunflower straw grid sand barrier, and sunflower straw line sand barrier > corn straw grid sand barrier > CK.(3) Management duration had a significant impact on species β diversity. The rank of β index affected by sand barrier was showing as follows: clay line sand barrier > sunflower straw grid sand barrier and corn straw grid sand barrier > rice straw grid sand barrier and nylon grid sand barrier > wheat straw grid sand barrier, sunflower straw line sand barrier, and construction waste grid sand barrier > corn straw line sand barrier > CK. There were differences in sand barrier materials in community commonality index and community dissimilarity index. There was no significant difference among different types of straw sand barriers. However, there was a significant difference with clay line sand barrier and nylon grid sand barrier(P < 0.01).更多还原