保安湖大型底栖动物结构与分布格局研究

STRUCTURE AND SPACIAL DISTRIBUTIONAL PATTERN OF MACROZOOBENTHOS IN BAO'ANLAKE

  • 摘要: 2001年8月对保安湖大型底栖动物进行调查,共记录动物4门7纲25科54属70种。其中,软体动物为绝对优势类群(占总丰度的81.5%)。而腹足类的纹沼螺(Parafossarulus striatulus)、白旋螺(Gyraulus albus)、长角涵螺(Alocinma longicornis)、方格短沟蜷(Semisulcospira libertina)和铜锈环棱螺(Bellamya aeruginosa)为该湖泊的优势种。样点间平均物种丰富度7.1,平均Shannon-Winner指数1.34。刮食者是保安湖底栖动物的最重要的功能摄食类群(占总丰度的80%以上)。结合GPS,将野外调查数据构建GIS数据库。基于GIS软件平台,运用Kringing插值法,构建动物丰度、主要功能摄氏类群及生物多样性等的空间分布格局,较为直观地反映了保安湖底栖动物的分布情况。模拟出的底栖动物分布格局显示,底栖动物各参数在全湖的分布较不均匀,出现数个高分布区。比较底栖动物各种参数的分布格局图与优势水生植物分布格局图,发现总密度、软体动物丰度和Shannon生物多样性指数的高分布区域与水草总生物量的高值区有不同程度的重叠。这表明,保安湖高等水生植物的分布是影响其底栖动物的关键因子。

     

    Abstract: Investigation of macrozoobenthos was carried out in Bao’ an Lake in August 2001. All total, 70 taxa were identified from forty-two sampling sites, of which, 15 Oligochaeta 29 Chironomidae, 11 Gastropoda, two Bivalva, 9 other Insecta and 4 other forms. Mollusks constituted the most dominant group and accounted for more than 80% of the total abundance. Among which, Parafossarulus striatulus, Gyraulus albus, Alocinma longicornis, Semisulcospira libertine and Bellamya aeruginosa were the dominant species. The richness and Shannonπs diversity per site were all relatively low (7.1 and 1.34 respectively). Assemblages were composed mainly of scrapers (80. 0%) and collector2gatherers (11%), and to a lesser extent to other functional feeding groups. The investigation data were compiled and a GIS database of macrozoobenthos was established. A vector boundary map of the lake was digitized and georeferenced, then used to introduce sampling sites. Under the support of GIS software Arcview 3.2 and the relative extension modules (Spatial Analyst Extension 2.0 and Kringing Interpolator Extension 3.22 SA), the GIS database was employed to simulate spacial distribution patterns of parameters of macrozoobenthos. The simulation process was based on the principle of Kringing interpolation technique. The simulated results were stored as Arcview Grid format with a grid precision of 20m. The simulated patterns of macrozoobenthos showed that these patterns were relatively high spatial heterogeneity, and distributions of most parameters of macrozoobenthos had usually 2-4 high value distributed zones in the whole lake. Comparison of patterns of total macrophytes biomass with different macrozoobenthos parameters showed that the total density, densityof mollusks and Shannon2Wiener index were overlapped in most highly distributed zone. The results indicated that macrophyte was the most important factor influencing the distribution of macrozoobenthos in the macrophyte2type lakes.

     

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