洪湖水生维管束植物区系研究

FLORA STUDIES ON AQUATIC VASCULAR PLANTS IN LAKE HONGHU

对不同的水生植物定义进行了分析，据此认为洪湖水生维管束植物区系丰富，计有118种5变种，共123个分类群，隶属于36科67属。包括世界广布属31属，热带属23属，温带属9属和4个热带温带过渡属。该湖水生维管束植物区系表现出比较明显的亚热带性质。在同一定义基础上，比较了洪湖与国内其它11个湖泊的区系相似性，各湖泊与洪湖相似系数的大小与其所处的地理位置、湖盆形态、理化环境、气候条件，以及湖泊发展历史等因素都有关系。分析认为，洪湖水生维管束植物区系近40年来并未发生显著的变化。

Lake Honghu, which covers an area of 344. 4 km2 and has its center at 29°49' N, 113°17'E, is the biggest lake at Jianghan Plain, and a good representative of the lakes in the middle and lower reaches of Changjiang River. Different definations of aquatic plant are discussed. The aquatic vascular flora in Lake Honghu comprises 123 taxa, belonging to 36 families and 67 genera. The subtropical character of the flora in the lake is quite obvious. Flora similarities of the lake and other 11 ones are compared on the same ground. The geographic position, shape of lake basin, physical and chemical environment, climate and lake history all affect the flora similarities. No obvious change is found about the flora in the lake during the past 40 years.