亚热带人工湿地中配置植物与迁入植物与迁移动物多样性的季节变化

人工湿地是为了净化污水而建造的一类系统,其环境特征既不同于自然湿地,也不同于一般陆地生境。人工湿地的生物多样性是一个新问题。作者以杭州植物园作为案例研究了亚热带地区人工湿地植物多样性的季节变化。结果表明:秋末人工湿地的物种数为72种,其中自然迁入植物54种;冬春季的物种数为46种,其中自然迁入物种33种。在人工湿地中,人工配置的植物种类仍然是群落结构的主体,迁入植物大部分处于伴生地位。应该在人工配置植物的基础上保留一些有价值的自然迁入植物,使人工湿地具有较高的生物多样性,这样既能充分吸收水中的多种营养成分,又能美化环境。亚热带地区可以有冬春和夏秋两个植物功能群在人工湿地中连续生长,这可以充分利用时间生态位,提高人工湿地在冬季的净化效果,增强人工湿地净化能力的季节间稳定性。

Seasonal variation of assembled and naturally recruited plants in a subtropical constructed wetland

Constructed wetlands are built mainly for purifying waste water. As a new type of ecosystem, its plant diversity remains unstudied. We studied the seasonal change in plant diversity in a constructed wetland in Hangzhou Botanical Garden, which is located in the humid subtropical area of China. In the autumn of 2002, 72 species were found, of which 18 were assembled and 54 were natural immigrants. In early spring of 2003, the species number was 46 in total, including 33 immigrants. Although naturally recruited plants exceeded the assembled ones in the species number, they were still associated species in the community, in which the assembled species form the dominant components. Some valuable immigrant species should be reserved to enrich biodiversity and to keep the stability of the community. In addition, the co-existence of two functional groups, respectively growing in warm seasons and cold seasons, can effectively occupy the temporal niche-space to prompt the efficiency of nutrient removal and seasonal stability of the constructed wetland.