| 摘要: |
| 采用群落学样方调查法,对中国的水生入侵种水盾草所侵入的沉水植物群落进行研究。主要以28个样地(包括4个对照样地)为调查对象,并将道场、太湖、陶堰、柯岩、方桥和五常6个作为固定样地进行每个季度的调查。α、β多样性测度公式分析,结果表明,(1)各个调查群落的物种组成差异都较大,物种数目不等;固定样地大多在不同季节中物种数目有所变化,春夏季多,冬季少。(2)一般样地的3个α多样性指数中,Simpson指数和Shannon-Wiener指数变化较为一致,Pielou均匀度指数变化不太一致。物种多样性与水盾草的入侵程度有关,水盾草优势程度越高,物种多样性就越低。(3)对照样地α多样性指数与相应的一般样地比较,多样性也与优势度相关。(4)固定样地α多样性指数一般冬季较其他三个季度低,但2001年与2002年没有大的差异。(5) βT多样性指数显示,在0.4-2.4m水深,种类组成都有所改变,在0.4-0.8m和0.8-1.2m种类改变较多,且以稀有种类为主。水盾草对本土水生植物有负面影响,应引起高度重视,进行相关研究。 |
| 关键词: 水盾草 生物入侵 入侵程度 α多样性 β多样性 乡土种 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目,39970145号;浙江省自然科学基金资助项目,302002号 |
|
| IMPACT TO NATIVE SPECIES BY INVADED SUBAQUEOUS PLANT CABOMBA CAROLINIANA |
|
DING Bing-Yang1, JIN Xiao-Feng2, YU Ming-Jian3, YU Jian3, SHEN Hai-Ming4, WANG Yue-Feng4
|
|
1.School of Life & Environment Science, Wenzhou University, Wenzhou, 325027;2.School of Life & Environment Science, Hangzhou Normal University, Hangzhou, 310036;3.College of Life Sciences, Zhejiang University, Hangzhou, 310012;4.Department of Biological Sciences, Shaoxing University, Shaoxing, 312000
|
| Abstract: |
| Cabomba caroliniana (Fanwort) is an aquatic exotic species in China, and it has affected native subaqueous species in bio-diversity. A survey on plant community was carried out in 24 regular sites where C. caroliniana distributed and 4 control localities free of the species in the areas of Daochang, Taihu, Taoyan, Keyan, Fangqiao and Wuchang, Southeast China. Regular sampling was conducted seasonally between 2000 and 2002. Aqueous plant samples in these localities were collected in a designed procedure regarding area and depth at certain intervals from water margin onward until no subwater plant can be sampled. The collected sample were then cleaned and dried for chemical researches to determine the bio-diversity in study areas indicated by α- and β-diversity indices. The results show that the species composition and species number are different among regular and control sites. The number of species in most regular sites varies seasonally, greater in spring and summer than in winter. Species diversity in the 24 sites have shown clear influence by the invasion of C. caroliniana; the longer the invasion time, and the stronger the C. caroliniana dominance, and the lower the bio-diversity. In the invasion sites, α diversity indices often show two peaks. Generally speaking, the or-diversity in winter is lower than the other three seasons. On the other hand, βT-diversity indices show that the changes in diversity occur in 0.4 - 2.4-m in water depth, especially in 0.4 - 0.8 and 0.8 - 1.2-m in water depth. The easily affected species included some rare species, such as Ottelia alismoides, Najas oguraensis etc., and some incidental species, as C. caroliniana often grows in these water depths and has impact those previously lived plant species. The fast proliferation of C. caroliniana not only affects the existence of the rare species clearly, but also threaten Ceratophyllum demersum and Hydrilla verticillata potentially. In future, more studies should be carried out on this notorious invasive plant. |
| Key words: Cabomba caroliniana, Biological invasion, Invasive degree, α-diversity, β-diversity, Native species |
