莫莫格湿地植被结构研究及其对碱性湿地演替的启示

莫莫格湿地属于典型的松嫩平原碱性湿地,在白鹤的全球迁飞网络中具有重要意义,但其退化过程中植被结 构的变化及影响因素尚不明确。以植被调查和土壤取样为基础,采用双向指示种分析(TWINSPAN)和去趋势对 应分析(DCA)结合的方法对该地区植被进行分类,并以去趋势典范对应分析(DCCA)的方法研究当地物种与环 境因素的关系。结果显示,莫莫格湿地的植被可以划分为9 种类型,即羊草群落、水蓼群落、扁秆藨草群落、鹅绒 委陵菜群落、芦苇群落、毛马唐群落、狗尾草群落、虎尾草群落和蒿类群落,其中虎尾草群落和蒿类群落是分布最 为广泛的2 个类型。莫莫格湿地植被主要组成部分为中生植物群落,表明该湿地正处于退化过程中,植被类型 可归类为退化草甸。植被演替的根本原因在于湿地水文条件的变化,而土壤pH 值、电导率和有机质含量也是影 响该地区植被结构的重要因素。适当干扰促进了虎尾草单优势种群落的形成,羊草群落和过度放牧不是其出现 的必要条件。 

Vegetation composition of Momoge wetland and its implications for succession in alkaline wetland

Momoge is a typical alkaline wetland in Songnen Plain. Although the Momoge wetland serves as a vital habitat in the global flyway of white crane ( Grus leucogeranus ), the changes of vegetation composition and related environmental factors in this region during its degradation remain unclear. Based on the vegetation survey and soil sampling in the field, Two-Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA) were used to classify the vegetation. Detrended Canonical Correspondence Analysis (DCCA) was also used to explore the relationship between vegetation composition and environmental factors. The results are: vegetation in the Momoge wetland is classified into nine types, i. e. Leymus chinensis community, Polygonum hydropiper community, Scirpus planiculmis community, Potentilla anserina community, Phragmites australis community, Digitaria ciliaris community, Setaria viridis community, Chloris virgata community and Artemisia sp. community, of which the C. virgata community and the Artemisia sp. community are of high prevalence. Vegetation in the Momoge wetland is dominated by communities of mesophytes, indicating that degradation is ongoing and the vegetation of this wetland can be classified as degraded meadow. The fundamental cause for vegetation differentiation in this wetland is the change of water regime though soil PH value, conductivity and the amount of organic matter are identified as the significant environmental factors associated with it. A certain degree of disturbance caused the prevalence of the C. virgata community, independent of previous vegetation or over-grazing.