OOS 30-8 - Vegetation response to hydrologic remediation on altered floodplains

Thursday, August 11, 2016: 10:30 AM
Grand Floridian Blrm H, Ft Lauderdale Convention Center
Beth A Middleton, NWRC, USGS, Lafayette, LA
Background/Question/Methods

Freshwater supply is becoming a key conservation issue for coastal freshwater wetlands, because freshwater is becoming more limited due to increased anthropogenic water usage and climate-induced drought. In this study, drought and excessive water extraction were documented in Big Thicket National Preserve (TX), which led to the death of many freshwater trees because salinity levels began to rise in these forests. We asked if tree production and regeneration in coastal swamps might increase if salinity levels became lower. We measured tree production and regeneration and compared these tree health indicators to water salinity and depth based on regional water gage information across the Gulf Coast of the United States.

Results/Conclusions

Tree production increased in JLNHP&P after four months of water freshening in 2010 versus other years (2007−15). Similarly, tree health increased dramatically after two months of hydrologic remediation in a study of Eucalyptus forests along the Murray River (Australia). These observations indicate that hydrologic remediation could be a useful engineering tool to improve environments in impaired freshwater tidal forests. Even short−term releases of freshwater can benefit the health of freshwater species in tidal coastal forests, so that these water management tools may help managers to offset future conservation problems due to climate change and/or water extraction