Water

Wildfires are landscape scale disturbances that can significantly affect hydrologic processes such as runoff generation and sediment and nutrient transport to streams. In Fall 2016, multiple large drought-related wildfires burned forests across the southern Appalachian Mountains. Immediately after the fires, we identified and instrumented eight 28.4–344 ha watersheds (four burned and four unburned) to measure vegetation, soil, water quantity, and water quality responses over the following two years. Within burned watersheds, plots varied in burn severity with up to 100% tree mortality and soil O-horizon loss. ...

Soil water repellency induced by wildfires can alter hydraulic properties and hydrologic processes; however, the persistence and vertical position (i.e., depth) of water repellent layers can vary between systems and fires, with limited understanding of how those variations affect infiltration processes. This study occurred in two forested locations in the south-central Appalachian Mountains that experienced wildfires in late 2016: Mount Pleasant Wildfire Refuge, Virginia, and Chimney Rock State Park, North Carolina. In each location, sites were selected to represent unburned conditions and low to moderate burn intensities.

In upland oak (Quercus spp.) forests of the Eastern United States, shade-intolerant, fire-tolerant oaks are being replaced by shade-tolerant, fire-sensitive species due to changes in forest management and fire regimes. In these mixed-species forests, rainwater redistribution by the forest canopy is determined by tree species traits as well as canopy position. To better understand how shifting forest composition could impact rainwater partitioning, we quantified differences in canopy structure and the resultant net flux of water to forest soils in a series of experiments across the Southeastern United States. ...