In ponderosa pine (Pinus ponderosa) forests of the western United States, prescribed fires are used to reduce fuel loads and restore historical fire regimes. The season in which prescribed burns are performed and the interval between burns can have complex consequences for the ecosystem, including soil carbon cycling through the...
Forest soils contain a substantial portion of global terrestrial carbon stores. Forest management can influence the soil carbon pool and how soil organic matter functions. The long-term productivity of forests is an ongoing goal where land managers utilize biomass and timber. A site-specific understanding of intensively managed forests can ensure...
In intensively managed forest plantations in the northern Oregon Coast Range, herbicides are often applied during site preparation and early stand regeneration to reduce competition for resources for planted conifer seedlings. In addition to reducing competition for crop trees, herbicide applications may affect soil processes including decomposition and nutrient cycling,...
Small mountainous watersheds are disproportionate sources of land-derived particulate organic matter (POM) to long-term sinks like lake bottoms and the ocean. As such, these ecosystems are an essential component of the global carbon cycle. The burial of POM in lacustrine and marine sediments contributes to the drawdown of atmospheric CO2...
Forest soils and topography have long been known to influence forest productivity in complex terrain such as Oregon’s Coast Ranges. Incorporating physical site characteristics into predictions of forest growth and yield, however, has been problematic because of the high spatial variability of soil properties and the challenges associated with representing...
Soils contain the largest pool of carbon that is actively cycling on human timescales, leading many to view soils as a natural climate solution with multiple co-benefits. The field of soil science is rapidly evolving, but without a unified understanding of soil carbon dynamics. This dissertation leverages two distinct long-term...
Wildfire greatly impacts the composition and quantity of organic carbon stocks within watersheds. Most methods used to measure the contributions of fire altered organic carbon–i.e. pyrogenic organic carbon (Py-OC) in natural samples are designed to quantify specific fractions such as black carbon or polyaromatic hydrocarbons. In contrast, the CuO oxidation...
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...
Remote sensing techniques have been applied extensively in geospatial investigations, but their use in measuring soil physical attributes has been far less explored. Soil particle size distributions (PSD) are indispensable in modeling pedological and hydrological processes as well as biodiversity. However, estimation of PSD via gravimetric measurement methods, the standard...
Over the course of the last century, a successful history of fire suppression has contributed to unsuccessful present day control over wildfire. In the absence of fire and the janitorial and ecological services it provides, drier inland forests are shifting in species composition and exceeding densities that cannot survive and...