松嫩平原湿地植被对生境干-湿交替的响应

Response of the Wetland Vegetation to Dry-Wet Alternating Habitat in the Songnen Plain of China

扎龙湿地和向海湿地水分布存在不均一性 ,生境中有“干 -湿”交替过程。选取“干 -湿”界面上沼泽植被与草甸植被共存的群落片断分别设置 1 5个固定样方 ,生长季内 4个月观测结果表明 :扎龙湿地和向海湿地生境旱生化时羊草为优势种群 ,湿生化时芦苇为优势种群 ,芦苇沼泽群落和羊草草甸群落随生境“干 -湿”交替过程相互演替 ,演替过程既受生境水分波动的影响 ,又由优势种群内在生物学特性决定。

Soil moisture condition was non equably distributed in Zhalong wetland and Xianghai wetland in the Songnen Plains, and there was a dry wet alternation among serial habitats in the two wetlands. There was distinct difference in succession series of vegetation communities from xerophilization habitat to hygrocolization habitat. Fifteen fixed quadrates were established on vegetation segment of dry wet interface, including meadow and marsh vegetation in Zhalong wetland and Xianghai wetland respectively. Size of all quadrates was designed as 1m×1m. The results of vegetation observation from May to August showed that the number of Leymus chinensis population reduced sharply from xerophilization to hygrocolization habitat and disappeared in wet habitat not only in Zhalong wetland but also in Xianghai wetland. The number of Carex duriuscula population distributed like a parabola with two peak value along the dry wet habitat in Zhalong wetland, but no Carex duriuscula in Xianghai wetland. The number of Phragmites australis population increased from xerophilization to hygrocolization habitat in Zhalong wetland. The edge of hydrophytic habitat was dominated by Phragmites australis , whereas Typha angustifolia was the dominance population in the hydrophytic habitat in Xianghai wetland. Analysis of dynamic of population and relative dominance demonstrated that Leymus chinensis is the dominance population in xerophilization habitat, but Phragmites australis in hygrocolization habitat in the Songnen Plains. Mutual succession occurred in Leymus chinensis meadow vegetation and Phragmites australis marsh vegetation with following dry wet alternation. Vegetation succession was influenced by both soil moisture fluctuation and biological characteristic of dominance population.