外源磷输入对兴凯湖沼泽土壤种子库种子萌发的影响

Effect of Exogenous Phosphorus Inputs on Seed Germination of Soil Seed Bank in Marshes in Xingkai Lake

通过温室萌发实验,研究磷养分输入对兴凯湖狭叶甜茅(Glyceria spiculosa)沼泽、槽鳞扁莎(Pycreus korshinskyi)沼泽、恢复沼泽、大豆地和水稻田土壤种子库种子萌发的影响。结果表明,磷养分输入并没有显著影响狭叶甜茅沼泽、槽鳞扁莎沼泽土壤种子库种子萌发的物种组成,但是随着磷养分由低—中—高浓度的输入,两者的种子库萌发幼苗数呈现减小—增加—显著减小的变化。其中,8g/m3磷养分输入使二者的种子库种子萌发幼苗数量显著减少(p<0.05)。磷养分输入对恢复沼泽和农田的土壤种子库种子萌发影响不明显。2g/m3磷养分输入显著减少了狭叶甜茅沼泽土壤种子库中野稗(Echinochloa crusgalli)的幼苗萌发数量,而磷养分浓度达到8g/m3时,槽鳞扁莎和三裂慈菇(Sagittaria trifolia)的幼苗萌发数量显著减少。磷养分输入可能会抑制狭叶甜茅和槽鳞扁莎沼泽物种的种子萌发数量,进而改变沼泽植物群落结构。应注意控制沼泽中营养物质的输入,以维持沼泽植物群落结构和生态系统的稳定。

A seed bank assay was performed in a greenhouse to evaluate the effects of phosphorus enrichment on seed germination from seed banks of marshes dominated by Glyceria spiculosa and Pycreus korshinskyi,restored marsh and soybean field and paddy field in Xingkai Lake area respectively.The results showed that phosphorus nutrient inputs didn＇t have significant effects on the composition of species germinated from soil seed banks of natural marshes dominated by Glyceria spiculosa and Pycreus korshinskyi respectively.But with the contents of phosphorus nutrient inputs increased from 2g/m3 to 8g/m3,the number of seedlings germinated from the two natural marshes showed the trend from decreasing to increasing to significant decreasing,8g/m3 phosphorus nutrient input resulted in the number of seedlings germinated from the two natural marshes decreasing significantly.Phosphorus nutrient inputs didn＇t significantly affect seedlings emergence from restored marsh and crop fields.The number of seedlings of Echinochloa crusgalli decreased significantly with 2g/m3 phosphorus nutrient input,while Pycreus korshinskyi,Sagittaria trifolia decreased significantly with 8g/m 3 phosphorus nutrient input,which meant that phosphorus nutrient inputs might affect the number of seedlings of the species in marshes and cause the alteration of plant community structure and composition of marshes.The nutrient enrichment should be considered and controlled to protect the stabilization of plant communities and ecosystem in wetlands.