Droughts and floods are more important than other climate change factors in the regeneration of freshwater species

Beth A. Middleton, USGS National Wetlands Research Center, beth_middleton@usgs.gov (Presenter)

Climate change could shift the biodiversity and dominance patterns of freshwater wetlands depending on the regeneration responses of species to climate change environments. While many aquatic species can persist for years in seed banks, little is known about how these species may regenerate under the conditions predicted under climate change scenarios. Wetland environments affecting plant regeneration in central North America may change by 2050 according to the IPCC so that episodes of supra-seasonal drought interspersed with severe flooding may increase. At the same time, higher levels of atmospheric CO2 also are predicted. The objectives of this study were to determine if either the emergence of seeds from seed banks or seedling growth were affected by interactions of these factors as based on evidence from growth chamber and field studies. The field study included long-term research sites in freshwater T. distichum swamps in floodplains of the Mississippi River along a latitudinal gradient from Illinois to Louisiana. The responses of freshwater wetland species to CO2 were not directly related to carbon assimilation strategy (i.e., C3 vs. C4 type), but instead depended on complex interactions of climate factors, which were dominated by water regime. Modeling of the effects of climate change on wetlands is limited by the lack of information regarding the interactive regeneration responses of freshwater species to climate change environments.

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

• Related Activity

Poster Location ID: 240