生物防治稻田与普通稻田水体中浮游植物的生态特征研究

通过对大沙镇生物防治稻田及普能稻田水体中浮游植物的调查研究，共检出藻类112种，其中生物防治稻田中82种，普通稻田中89种，稻田水体中的浮游植物以硅藻、裸藻和绿藻占优势，在普通稻田中，硅藻种类数超过生物防治稻田，其优势度最高的5种藻类中除双对栅藻外，其余4种均为硅藻；而在生物防治稻田中，裸藻种类数高于普通稻田，且其优势度最高的5种藻类中有两种为裸藻，通过比较发现，生物防治稻田不体中浮游生物的密度明显高于普通稻田，对水体浮游植物多样性及均匀度的分析表明，稻田水体中的浮游植物自秧苗插上至干田期间，多样性指数略有上升（上要是由于种类数的增加引起的），而均匀度呈下降趋势。

Ecological characteristics of phytoplankton in waters of biological-controlling and ordinary rice fields

Through investigations from March to June 1998 on the phytoplankton in waters of biological controlled and ordinary rice fields,112 species of phytoplankton were found,of which, Bacillariophyta,Euglenophyta and Chlorophyta were dominant.The comparison of the species in two rice fields showed that in biological controlled rice field,there were more species of Euglenophyta ,with 5 most dominant species,i.e.,2 of Euglenophyta ,2 of Bacillariophyta and 1 of Chlorophyta .In ordinary rice field,there were more Bacillariophyta species,in which,5 most dominant species belonged to Bacillariophyta ,except Scenedesmus bijuga to Chlorophyta .The biodiversities of phytoplankton and their evennesses were also analyzed with the period from the seedlings being planted to the rice fields being dried,showing that a little increase in their biodiversity mainly caused by the increase of species number and an evident decrease in their evennesses.