溪流底栖动物定量与半定量采样法比较研究

溪流底栖动物定量和半定量采样法在个体数、物种数、物种相似性及生物指数方面的比较研究表明:(1)急流生境中,半定量样(踢网)的个体和物种数高于定量样(索伯网);静水-缓流生境中,半定量样(D形网)的个体和物种数一般高于定量样,且物种数有显著差异(z=-2.032,P<0.05).(2)同一样点半定量样(踢网加D形网)与定量样之间的物种相似性(平均为0.68)高于急流生境(0.56)和静水-缓流生境(0.45).(3)同一样点半定量样和定量样单独计算的生物指数值之间无显著差异.建议在应用溪流底栖动物开展水质生物评价时,可用半定量采样法完成野外采样.图4表1参8

Comparison of Quantitative and Semiquantitave Sampling Methods for Stream Benthic Macroinvertebrates

Quantitative sampling method for stream macroinvertebrates was well used in stream ecological study, and semi-quantitative method was widely used in water quality bio-assessment. The results from comparisons of species number, individuals and values of metrics between the two methods showed: (1) Between quantitative (Surber net) and semi-quantitative (kick net) samples, species number showed no significant difference in the lotic habitat, but in the lentic habitat it showed significant difference (z=-2.032, P<0.05); (2) In the same site, the average species similarity was 0.68 between semiquantitative and quantitative samples, higher than those in the lotic habitat (0.56) and the lentic habitat (0.45); (3) No significant difference was found in metrics calculated from the data of quantitative and semiquantitative samples, respectively. The semi-quantitative can be used as a practical method for macro-invertebrate assemblage sampling in water quality bio-assessment. Fig 4, Tab 1, Ref 8