长江马鞍山段沿岸陆生植物分布及多样性研究

Terrestrial Plants Distribution and Species Diversity along Both Sides of Ma'anshan Reaches of Yangtze River

为探究人类活动对长江马鞍山段陆生生态的影响,对该段长江沿岸及江心洲进行了实地调查,研究了其陆生植物现状,结果表明:(1)该江段共有陆生植物49科140属190种,平均物种丰富度高达1.32 sp·km^(-2),高于长江安徽段平均值,两岸2 km范围内陆生植物调查具有一定的代表性;(2)该江段优势种为禾本科(Gramineae)和菊科(Compositae)、莎草科(Cyperaceae)及蓼科(Polygonaceae),世界分布科占总科数的比例高达57.14%,植物区系分布具有过渡性质,外来物种入侵风险大;(3)该江段单种属和寡种属占总属数的97.9%,中国特有属仅有2种,人工化较为严重;(4)该江段α多样性指数与物种丰富度分布规律相似,整体上呈江心洲和江东区略高于江西区,但各区β多样性指数相近,高强度人类干扰掩盖了区域自然环境差异。

In order to assess the effect of anthropogenic activities on the terrestrial plants on both sides of Ma’anshan reaches,and to get more information about the terrestrial plants resources,terrestrial plants in2km buffer area of both sides and islands in Ma’anshan reaches are analyzed through the field investigation.The results show that:(1)there are49families,140genera,and190species of terrestrial plants in Yangtze River of Ma’anshan.The average species richness in Ma’anshan Reaches accounts for1.32sp·km^-2,and it is much more than that in Anhui reaches.Plant investigation in2km area of both sides of Ma’anshan reaches has a certain representation.(2)The preponderant families are Gramineae,Compositae,Cyperaceae and Polygonaceae,and widespread families are dominant,accounting for57.14%.Based on the floristic distribution,the distribution of terrestrial plants in this area has a characteristic with transition from the nature to anthropogenic interference.It has high risk of alien species invasion.(3)The genera mainly contains regional one-seeded genus and depauperate genus which cover97.9%of total genera,and endemic species of China are very few with2species.In this reaches,artificialization of terrestrial plants is more serious.(4)The spatial distribution rules of species richness andαdiversity are similar and the values of them in river continents and east of Yangtze River are slightly more than that of west of Yangtze River.However,theβdiversity indexes in the above mentioned three areas are approximately equal,which indicates that drastic human activity conceals the differences of regional environmental change.