The diatom flora and its seasonal changes in a paddy field in Central Japan
Ohtsuka, Taisuke; Fujita, Yuko
Between June 1995 and April 1996 we studied the identity and community structure of epipelic diatoms in a paddy field in Central Japan. Seventeen samples were collected, in which a total of 92 diatom taxa belonging to 28 genera were found. The dominant genera were Nitzschia (13 taxa), Navicula (9 taxa) and Pinnularia (8 taxa). The paddy field was flooded on June 12th, and irrigated until October 6th, 1995. Most diatoms increased in number after flooding and decreased after drainage. Nitzschia palea was dominant in June. From July to October, dominance varied between Navicula trivialis, Pinnularia mesolepta var. intermedia, Nitzschia clausii and Navicula veneta. Between December and April, Hantzschia amphioxys was usually dominant. Many of the diatoms in the paddy-field community belonged to species that usually inhabit brackish water, such as Fallacia and Tryblionella spp.