长江口潮间带大型底栖动物群落演替

The re-colonisation progress of intertidal benthic fauna community in the Changjiang Estuary

2006年1月在崇明岛西端的潮间带湿地进行了一项生态工程,经过土方工程的区域被选为大型底栖动物群落演替区,因为其中的大型底栖动物群落受到了较大破坏,在其周边未受干扰区设立对照样点。试图通过群落重建群的研究分析3个问题:(1)在群落恢复过程中不同的生态学指标如何变化?(2)群落演替过程中什么先增长,生物量还是复杂性?(3)是否可以选择生态学指标以利于演替过程中3类不同增长模式(生物量、网络结构和信息量)的识别?多变量分析用于检验被干扰区群落是否已经得到恢复。Shannon-Wiener指数、Margalef指数、Pielou均匀度指数、能质(exergy)和结构能质(Specific exergy)用于分析演替过程中群落状态的变化。结果显示物种随时间的更替与群落结构变化密切相关。物种丰富度增长迅速,而且对照区和演替区的物种组成非常相似。演替进行1个月左右之后,演替区的生物多样性已经超过了对照区。能质和结构能质提供了群落结构发展的有用信息,但仍然缺乏鉴别系统所处信息状态的能力。多样性分析结果可以从中度干扰假说(Intermediate Disturbance Hypothesis)得到很好地解释。总体而言,干扰的空间尺度决定了群落的恢复特征,如果干扰区域明显小于周边未受干扰的区域,那么群落的复杂性(信息量和网络结构)将先于生物量得到恢复。

The January, 2006. study was carried out in a intertidal fiat after ecological engineering at the west of Chongming Island in Succession plots were disturbed by ecological engineering and Macrobenthos community were damaged severely. Through a re-colonisation field study three main questions were approached： （1） How do different ecological indicators react during the process of recovery？ （2） What does grow first during complexity？ （3） Can the chosen ecological indicators help in recognising the three network and information disturbed plots with the a community succession, biomass or proposed forms of growth ： biomass, , throughout re-colonisation？ Multivariate analysis was performed to examine the convergence of the surrounding community during recovery. Shannon Wiener Index, Margalef Index, Pielou evenness, exergy and Specific exergy were applied to characterize the state of the community during the recovery process. Results showed that the replacement of species over time happened associated Macrobenthos community. Species richness increased rather rapidly and species composition was similar in disturbed and undisturbed areas. After 1 month, diversity was consistently higher in the community undertaking recovery. Exergy and Specific exergy provided useful information about the structural development of the community but lacked discriminating power with regard to the informational status of the system. The observations appear to illustrate a case explainable by the Intermediate Disturbance Hypothesis （IDH）. Overall, the characteristics of a systems＇ recovery after disturbance appear to be dependent on the spatial scale of the disturbance. If a disturbed area is small when compared to a contiguous non-disturbed one, complexity （ information and network） will recover prior to biomass.