Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir (Pseudotsuga menziesii) forest soils and have been estimated to cover up to 40% of the forest floor in some stands. Although previous studies have examined various aspects of EcM fungi, little is known about their associated microbial...
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...
As a result of a warming climate, subsequent declining snowpack, and a century of fire suppression, forest fires are increasing across the western United States. However, we still do not fully understand how forest fire effects snowpack energy balance, nor the volume and availability of snow melt and associated water...
Rainfall interception is a primary control over the moisture input to a forested ecosystem through the partitioning of precipitation into throughfall, stemflow, and an evaporated component (i.e. the interception loss). Rainfall interception is a spatially and temporally varying process at multiple scales, but heterogeneity in interception processes are poorly understood...
The structure and composition of mixed-conifer forest (MCF) in central Oregon has been altered by fire exclusion and logging. The resulting increased density, spatial contagion, and loss of fire resistant trees decrease the resiliency of this ecosystem to fire, drought, and insects. The historical and current composition and structure of...
Ecosystem nitrogen (N) supply strongly influences the availability and cycling of other essential nutrients in temperate forests, especially calcium (Ca). Short-term additions of N that exceed ecosystem demands often increase dissolved nitrate fluxes and decrease soil pH, which can stimulate soil Ca loss. However, the long-term effects of high N...
Prior to 2005, ammonia oxidation, the first step of nitrification, was thought mediated mainly by ammonia-oxidizing bacteria (AOB). However, the discovery of Thaumarchaeota carrying the genes coding for the ammonia monooxygenase (AMO) enzyme led to the discovery that ammonia-oxidizing archaea (AOA) also contribute to nitrification. Despite the uptick in studies...
Calcium (Ca) is an essential macronutrient that is increasingly recognized as a biogeochemical factor that influences ecosystem structure and function. Progress in understanding the sustainability of ecosystem Ca supply has been hampered by a lack of information on the various forms and pools of Ca in forest ecosystems. In particular,...
Molybdenum is an essential component of biogeochemical cycling, most notably as a component of the nitrogenase enzyme used in biological nitrogen (N) fixation. While the important role of phosphorus (P) in limiting N fixation in ecosystems has been well documented, occurrence and prevalence of molybdenum (Mo) limitation is largely unknown....
Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in...