筑後川下流域水田地帯のクリークにおける水生雑草の実態 : 第4報雑草繁茂量の時期別変遷

概要

論文の詳細を見る
Yearly changes of cover degrees of aquatic weeds were investigated in 1974 to 1977. Waterhyacinth [Eichhornia crassipes (Mart.) Solms] changed it biggest during four years, and its percentage was the highest in 1975, and the lowest in 1977. These changes appeared to be affected with temperature condition in every winter. Hairly subspecies of knotgrass (Paspalum sp.) increased it gradually year by year and became the worst weed in the investigated creeks. The cover degree of parrotfeather (Myriophyllum brasiliense Camb.) changed little yearly, but it decreased strikingly in 1977 because of laborious hand weeding in many creeks. Several other weeds increased little by little although they were still unimportant. Seasonal change of that of waterhyacinth was also biggest, as almost all plants died of cold temperature in every winter. However, submerged shoots of Paspalum spp. and parrotfeather were alive even in winter and, therefore, their cover degrees did not change so much seasonally. Several species as giant duckweed [Spirodela polyrhiza (L.) Schleid.] changed them a little by season.
日本雑草学会の論文
1978-10-25