Impacts Of Durative Waterlogging For Controlling Of Spartina Alterniflora On The Saltmarsh Soils

Biological invasion, an important component of the global change, is considered as one of the three major environmental problems, and may profoundly afeect native biological diversity, ecosystem stability and service function. Since introduced into the Chongming Dongtan Nature Reserve in 1995, Spartina alterniflora has rapidly expanded and seriously threatened the biological diversity there. To control and eradicate the exotic and invasive plant Spartina alterniflora is important and necessary for biodiversity conservation management.In order to study the impact of a technique of cutting plus waterlogging to control S. alterniflora and drainage recovery on the physical and chemical properties of saltmarsh soils, this study was carried out to trace the change of the content of the organic matter, chloridion, bicarbonate ion, calcium ion, magnesian ion, sulfate ion and pH value of the saltmarsh soils after performing a technique of cutting plus waterlogging and the recovery after apply the technique of drainage on a demonstration site to control Spartina alterniflora in the Chongming Dongtan nature reserve. The results showed:1. Durative waterlogging could reduce contents of organic matter of the saltmarsh soils, while increase pH value, contents of chloridion, bicarbonate ion, calcium ion, magnesian ion and sulfate ion of the saltmarsh soils. These impacts were enhanced with increasing duration of waterlogging. Therefore, to apply the integrated technique of cutting plus waterlogging for controlling S. alterniflora, it is necessary to reduce the duration of waterlogging that can provide a possible condition for effectively controlling S. alterniflora and restoration of the damaged wetlands.2. The control measure of durative waterlogging could have a negative impact while such negative impact could be restored gradually after applying the technique of drainage recovery. Drainage recovery could increase contents of organic matter while reduce pH value, contents of chloridion, bicarbonate ion, calcium ion, magnesian ion and sulfate ion of the saltmarsh soils. The results from the study indicated the negative impacts caused by durative waterlogging could be reduced gradually and these impacts were enhanced with increasing duration of drainage.