Effects of light and substrate on the benthic diatoms in an oligotrophic lake: a comparison between natural and artificial substrates

摘要: Benthic diatoms form a particularly important community in oligotrophic lakes, but factors influencing their distribution are not well known. This study reports the depth of living motile and total (living plus dead diatoms) on both natural (from sand to fine organic mud) artificial substrates an lake. On substrates, diatom densities peaked abundance (24-30 cells · mm(-2) ) between 0.6 1.9 m depth; sediment surfaces, were generally more numerous (925 cells · mm(-2) at 1.3 m depth. Total highest (1260 valves · mm(-2) 0.6 m depth, with very low values below 3 m abundances much higher (21600 valves · mm(-2) declined gradually Significant relationships found light substrate. Ordination analysis indicated that substrate type significantly correlated variation composition substrates. Our results suggest influences benthic abundance, whereas has influence composition.