Modeling the potential impacts of climate change on the water table level of selected forested wetlands in the southeastern United States
|Authors:||Jie Zhu, Ge Sun, Wenhong Li, Yu Zhang, Guofang Miao, Asko Noormets, Steve G. McNulty, John S. King, Mukesh Kumar, Xuan Wang|
|Station:||Southern Research Station|
|Source:||Hydrology and Earth System Sciences|
AbstractThe southeastern United States hosts extensive forested wetlands, providing ecosystem services including carbon sequestration, water quality improvement, ground- water recharge, and wildlife habitat. However, these wet- land ecosystems are dependent on local climate and hydrol- ogy, and are therefore at risk due to climate and land use change. This study develops site-specific empirical hydro- logic models for five forested wetlands with different char- acteristics by analyzing long-term observed meteorological and hydrological data. These wetlands represent typical cy- press ponds/swamps, Carolina bays, pine flatwoods, drained pocosins, and natural bottomland hardwood ecosystems. The validated empirical models are then applied at each wetland to predict future water table changes using climate projec- tions from 20 general circulation models (GCMs) participat- ing in Coupled Model Inter-comparison Project 5 (CMIP5) under the Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios. We show that combined future changes in precipitation and potential evapotranspiration would sig- nificantly alter wetland hydrology including groundwater dy- namics by the end of the 21st century. Compared to the his- torical period, all five wetlands are predicted to become drier over time. The mean water table depth is predicted to drop by 4 to 22 cm in response to the decrease in water availabil- ity (i.e., precipitation minus potential evapotranspiration) by the year 2100. Among the five examined wetlands, the de- pressional wetland in hot and humid Florida appears to be most vulnerable to future climate change. This study pro- vides quantitative information on the potential magnitude of wetland hydrological response to future climate change in typical forested wetlands in the southeastern US.
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