镇江内江湿地植物群落演替过程中土壤养分动态研究

镇江内江湿地是由长江携带的泥沙在镇江内江特有的水文条件下淤积而成,形成于江滩裸地上的植物群落开始了群落的原生演替过程。在此过程中,湿地的土壤养分状况随着植被的演替更迭,发生着协同演化的过程。为了进一步丰富群落演替理论,通过研究群落演替过程中不同阶段以及同一演替阶段不同层次土壤养分状况的时空变化,探索演替过程中的不同植被类型和土壤养分变化的内在联系及其互作效应。结果表明,随着演替进行,土壤的养分状况趋于改善,土壤有机质、全氮和速效磷含量呈上升趋势,只有速效钾的含量在后期芦苇阶段明显降低,这主要是由于收割芦苇将富含钾素的芦苇植株带出湿地系统所致。由于植物根系分布及枯落物多少的差异,使得各营养成分的垂直分布各异。

Dynamics of soil nutritions in plant community succession process in inner-river wetland in Zhenjiang

The wetland near Yangtze River in Zhenjiang,Jiangsu,was formed by the sediment from this river and the local area special hydrological conditions.And the vegetable community in the wetland started natural community succession.Accompanied by the vegetation succession,the wetland soil nutrients were changed contemporarily.In order to enrich the community succession theory and explore the relationship and inter-effects of different vegetation types and the soil nutrients change,we studied the soil nutrients spatial change during different community succession stages and different soil layers in the same succession stage.The results showed: Along with the succession,the soil nutrients status was improved.The soil organic matter,total nitrogen and available phosphorus all elevated.However,only the available potassium descended in the late stage of phragmites communis mainly because the plant full of potassium was taken out of the marshland ecosystem when the phragmites communis was harvested.The differences of root distributions and litter amount resulted in the different vertical distributions of every soil nutrients.