Mountainous headwater streams make up ~80 % of stream length globally and are strongly connected with catchment hillslopes and riparian areas, which can influence water quantity, quality, and availability for downstream uses. Accordingly, effective management of headwater streams and riparian zones to maintain desired ecosystem services downstream is critical, particularly...
Our understanding of nitrogen (N) and phosphorus (P) variability in forested stream systems with minimal disturbance is confounded by the complex interactions of hydrologic and biogeochemical controls. In this thesis, our studies evaluate the variability of stream water N and P in a forested, headwater system in the Oregon Coast...
The extent and severity of wildfires in forested regions are increasing throughout many regions on the planet, including western North America. High-severity wildfires directly affect soils and vegetation by altering soil hydraulic properties, reducing soil organic matter, exporting carbon and nitrogen, and killing trees and understory vegetation. These impacts can...
The rapid pace of climate change is increasing tree mortality and highlighting the need to improve the mechanistic understanding of plant function under increased water stress. However, the processes that control soil moisture availability in steep mountainous terrain are poorly understood, as are the relative effects of atmospheric and soil...
Headwater streams represent the majority of the drainage area of a river network and provide many critical functions supporting aquatic and terrestrial ecosystem health. The riparian zones that surround these streams are transitional areas between terrestrial and stream ecosystems, which provide key habitat for aquatic and terrestrial organisms, especially during...
Shallow subsurface flow and surface runoff are spatially and temporally variable in forested environments. The location and timing of this runoff depends on both site characteristics (e.g., vegetation, soil texture, geology, and topography) and on time-varying conditions (e.g., soil water content, precipitation type, duration, magnitude, and intensity). Forest management activities...
In recent decades, the occurrence of large, high severity wildfires has increased substantially in many parts of the world, including the western United States. These fires have the potential to impact water quality, aquatic ecosystems, and downstream communities for many decades. As such, it is increasingly important to understand the...
Wildfires can affect soil physical properties, resulting in changes in infiltration, hillslope runoff, groundwater recharge, and sediment and dissolved nutrients to streams. In November 2016, the Chimney Tops 2 Fire burned 4,617 ha of Appalachian hardwood forest in eastern Tennessee. A portion of the fire burned through a National Ecological...
Timber harvesting practices can increase fine sediment inputs to streams due to increased hillslope soil erosion and mass wasting of roads, hillslopes, and stream channels. Excessive fine sediment depositions have been shown to impact aquatic ecosystems, fish habitat, and downstream community water supply. Despite these deleterious impacts, the influence of...
Understanding the magnitude and longevity of wildfire effects in forested watersheds and subsequent impacts to downstream aquatic ecosystems and communities requires congruent investigation into post-fire aquatic and terrestrial processes. However, results from wildfire studies are often confounded by pre- and post-fire land management actions and based on either hydrologic or...