退塘还湿生态修复效果评估——以天津七里海湿地为例

Evaluation on the ecological restoration effect of returning fishpond to wetland: A case study in Qilihai wetland, Tianjin, China

为筛选“退塘还湿”生态修复策略与技术方法,在天津七里海湿地选择腾退渔塘,开展了辅以先锋物种种植的人工强化恢复与自然保育恢复的“退塘还湿”生态修复对比实验。结果表明:恢复实验期间,人工强化恢复区与自然保育区共计调查到植物物种81种,其中自然保育区植物物种48种,强化恢复区植物物种77种;强化恢复区浮游植物、浮游动物、底栖生物的生物量分别为4.53~80.45、 6.75~109.90、 4.22~26.20 mg·L^(-1),其Shannon-Weiner指数也较为稳定,分别维持在2.58~3.13、1.55~1.82、0.29~0.58;实验期间,强化恢复区与自然保育区的湿生植物、挺水植物、浮游动植物及底栖动物的Shannon-Weiner指数和Pielou均匀度指数以及土壤微生物alpha多样性均无显著差异(P>0.05)。基于以上结果,对于塘堤原本就有芦苇等高等植物生长且距离天然湿地较近的鱼塘“退渔还湿”,建议采取自然保育的恢复方式。本研究结果可为华北地区腾退渔塘湿地修复提供参考。

In order to screen the appropriate ecological strategies and methods for fishpond restoration to wetland, a returned fishpond in Tianjin Qilihai Wetland was taken as a case study, and the comparative experiments were conducted between the natural restoration and the artificial enhanced restoration with pioneer species. Results showed that, 81 plant species were found in the whole study area, of which 48 species were in natural restoration zone and 77 species were in artificial enhanced restoration zone. Biomass for phytoplankton,zooplankton and benthos was 4.53~80.45、 6.75~109.90、 4.22~26.20 mg·L^(-1)in artificial enhanced restoration zone, and their Shannon-Weiner indices stably stayed at 2.58~3.13、1.55~1.82、0.29~0.58, respectively. During test period, there were no significant differences(P>0.05) in Shannon-Weiner index, Pielou index and alpha diversity index between both natural restoration zone and artificial enhanced restoration zone. Based on above results, it is proposed that natural restoration can be used for the fishpond with reeds on its pond bank and a nearby natural wetland to return fishpond to wetland. It can provide a reference for fishpond restoration and wetland protection in northern area of China.