A5000620404- Hydrology and Watershed Management Studies
- Soil and Water Nutrient Dynamics
- Fish Ecology and Management Studies
- Freshwater macroinvertebrate diversity and ecology
- Groundwater flow and contamination studies
- Fire effects on ecosystems
- Peatlands and Wetlands Ecology
- Groundwater and Isotope Geochemistry
- Marine and coastal ecosystems
- Wastewater Treatment and Nitrogen Removal
- Ecology and biodiversity studies
- Botany and Plant Ecology Studies
- Cryospheric studies and observations
- Flood Risk Assessment and Management
- Coastal wetland ecosystem dynamics
- Hydrology and Sediment Transport Processes
- Soil erosion and sediment transport
- Aquatic Ecosystems and Phytoplankton Dynamics
- Climate change and permafrost
- Microbial Community Ecology and Physiology
- Wildlife-Road Interactions and Conservation
- Landslides and related hazards
- Hydrological Forecasting Using AI
- Geology and Paleoclimatology Research
- Rangeland and Wildlife Management
Montana State University
2007-2024
Colorado State University
2014-2023
Waters (United States)
2018
Duke University
2012
Abstract Connectivity describes the efficiency of material transfer between geomorphic system components such as hillslopes and rivers or longitudinal segments within a river network. Representations systems networks should recognize that compartments, links, nodes exhibit connectivity at differing scales. The historical underpinnings in geomorphology involve management observations linking surface processes to landform dynamics. Current work emphasizes hydrological, sediment, landscape...
Abstract Biogeochemical processing of dissolved organic matter (DOM) in headwater rivers regulates aquatic food web dynamics, water quality, and carbon storage. Although are critical sources energy to downstream ecosystems, underlying mechanisms structuring DOM composition reactivity not well quantified. By pairing mass spectrometry fluorescence spectroscopy, here we show that hydrology river geomorphology interactively shape molecular patterns composition. River segments with a single...
Watershed resilience is the ability of a watershed to maintain its characteristic system state while concurrently resisting, adapting to, and reorganizing after hydrological (for example, drought, flooding) or biogeochemical excessive nutrient) disturbances. Vulnerable waters include non-floodplain wetlands headwater streams, abundant components representing most distal extent freshwater aquatic network. are hydrologically dynamic biogeochemically reactive systems, storing, processing,...
The mountain to alluvial valley transition is a dominant landscape of the American West, and mountainous regions around world, crucial water resources in these regions. We combined stream groundwater (GW) hydrometric methods with geochemical hydrograph separations investigate gains losses across southwestern Montana address following questions: (1) How do alpine bottom transitions affect discharge? (2) change transitions? There was an annual 23% net loss discharge zone, which we refer as...
Stream nutrient tracer additions and spiraling metrics are frequently used to quantify lotic ecosystem behavior. Of particular concern is the influence concentration exerts on retention export. However, characterizing response curves across a range of concentrations has remained challenging, in part due large effort required develop these using traditional (e.g., plateau or steadystate) approaches. Here we outline demonstrate new approach uptake kinetics from ambient saturation Tracer...
Hydrologic transport and retention strongly affect biogeochemical processes that are critical to stream ecosystems. Tracer injection studies often used characterize solute in reaches, but the range of accurately resolved with this approach is not clear. Solute residence time distributions depend on both in‐stream mixing exchange hyporheic zone larger groundwater system. Observed breakthrough curves have most commonly been modeled advection‐dispersion plus an exponential distribution,...
Abstract River networks that drain mountain landscapes alternate between narrow and wide valley segments. Within the segments, beaver activity can facilitate development maintenance of complex, multithread planform. Because segments have limited ability to retain water, carbon, nutrients, wide, are likely important locations retention. We evaluated hydrologic dynamics, nutrient flux, aquatic ecosystem metabolism along two adjacent a river network in Rocky Mountains, Colorado: (1) segment...
Abstract Pyrogenic carbon (PyC) constitutes a significant fraction of organic in most soils. However, PyC soil stocks are generally smaller than what is expected from estimates produced fire and decomposition losses, implying that other processes cause loss Surface erosion has been previously suggested as one such process. To address this, following large wildfire the Rocky Mountains (CO, USA), we tracked litter layer soil, through eroded, suspended, dissolved solids to alluvial deposits...
The exchange of water between streams and groundwater can influence stream quality, hydrologic mass balances, attenuate solute export from watersheds. We used conservative tracer injections (chloride, Cl − ) across 10 reaches to investigate gains losses at larger spatial temporal scales than typically associated with hyporheic exchanges. found strong relationships reach discharge, median velocity, gross loss a range morphologies sizes in the 11.4 km 2 Bull Trout Watershed central ID....
Abstract The discipline of hydrology has long focused on quantifying the water balance, which is frequently used to estimate unknown fluxes or stores. While technologies for measuring balance components continue improve, all have substantial uncertainty at watershed scale. Watershed‐scale evapotranspiration, storage, and groundwater import export are particularly difficult measure. Given these uncertainties, analyses based assumed closure highly sensitive propagation errors omission, where...
Hydrological and biogeochemical processes in stream reaches impact the downstream transport of nutrients. The output from one reach becomes input for next, leading to serial processing along networks. shape uptake‐concentration curve each indicates in‐stream biological uptake nutrient. Combined with physical retention due hydrologic turnover, both will control nutrient export downstream. We performed an instantaneous addition conservative (chloride, Cl) nonconservative (nitrate‐nitrogen, NO...
We have used a dynamic hydrologic network model, coupled with transient storage zone solute transport to simulate dissolved nutrient retention processes during flow events at the channel scale. explored several scenarios combination of rainfall variability, and biological geomorphic characteristics catchment, understand dominant factors that control nutrients (e.g., nitrate) along networks. While much experimental work has focused on studying base periods in headwater streams, our...
Abstract The role of stream networks and their hydrologic interaction with hillslopes shallow groundwater in modifying transporting watershed signals is an area active research. One the primary ways that can modify through spatially variable gains losses, described herein as turnover. We measured gain loss at reach scale using tracer experiments throughout Bull Trout Sawtooth Mountains Idaho. extended results to network empirical relationships between (1) discharge (2) percent water system....
Stream nutrient uptake and limitation are interconnected by relationships between supply demand. We used multiple approaches, including estimates of supply, measures stream metabolism derived from dissolved O2 curves, nutrient-enrichment experiments, as complementary demand, in New Hope Creek, a 3rd-order the Duke Forest North Carolina. Over course 1 y sampling, NO3−-N relative to demand (S∶D) was large during winter (S∶D = 133.4), spring 62.0), summer 108.32). Potential N estimated based on...
Abstract Watershed structure influences the timing, magnitude, and spatial location of water solute entry to stream networks. In turn, reach transport velocities network geometry (travel distances) further influence timing export from watersheds. Here, we examine how watershed organization can affect travel times delivery arrival at outlet. We analysed quantified relationship between discharge velocity across six study watersheds (11.4 62.8 km 2 ) located in Sawtooth Mountains central Idaho,...
Abstract Wildfire increases the potential connectivity of runoff and sediment throughout watersheds due to greater bare soil, erosion as compared pre‐fire conditions. This research examines post‐fire from hillslopes ( < 1.5 ha; n = 31) catchments 1000 10) within two 1500 ha) burned by 2012 High Park Fire in northcentral Colorado, USA. Our objectives were to: (1) identify sources quantify magnitudes at nested for rain storms with varied duration, intensity antecedent precipitation; (2)...
Abstract Long‐term observations are critical in hydrology to understand the dynamics of biological and physicochemical processes involved affected by flux water. have been employed provide basic understanding water cycle (e.g., infiltration, evaporation, run‐off generation, groundwater–surface interactions), but they lacking hydrologically relevant regions such as Andes Mountains, including alpine watersheds. Although call for long‐term data acquisition Latin America has made, establishment...
Abstract Land use within a watershed impacts stream channel morphology and hydrology and, therefore, in‐stream solute transport processes associated transient storage mechanisms. This study evaluated in two contrasting sites where was influenced by the surrounding land use, cover, climate geologic controls: Como Creek, CO, relatively undisturbed, high gradient, forested with gravel bed complex morphology, Clear IA, an incised, low‐gradient low‐permeability substrate draining agricultural...
Land use/land cover change often leads to increased nutrient loading streams; however, its influence on stream ecosystem transport remains poorly understood. Given the deleterious impacts elevated can have aquatic ecosystems, it is imperative improve understanding of retention capacities across scales and watershed development gradients. We performed 17 addition experiments six streams West Fork Gallatin Watershed, Montana, USA, quantify nitrogen uptake kinetics dynamics sizes (first fourth...
Abstract Within fluvial networks, lakes can be sinks or sources of dissolved organic carbon (DOC) and nutrients, yet the controls over sink‐source behavior remain unclear. We investigated influence that an in‐network lake exerted on DOC nutrient export. Our investigation consisted of: (1) injecting a conservative tracer to determine travel times flow paths; (2) sampling inflow, outflow, surrounding groundwater water budgets; and, (3) internal profiles ascertain in‐lake physico‐chemical...
Abstract Water‐mediated linkages that connect landscape components are collectively referred to as hydrologic connectivity. In river‐floodplain systems, quantifying connectivity is challenging yet enables descriptions of function emerge from complex, heterogeneous interactions underlying geomorphic, climatic and biologic controls. Here, we quantify surface water using field indicators develop a strength metric across system. To measure strength, analyzed hydrometric data, conservative...
Abstract Hydrologic fluctuations and geomorphic heterogeneity are expected to produce substantial variability in solute transport within rivers. However, this has not been sufficiently explored due the limited availability of injection data most Here, we analyzed 81 tracer breakthrough curves (BTCs) along Stringer Creek, a 5.5 km 2 watershed Montana. BTC measurements were obtained for three baseflow conditions at 27 reaches 2600 m stream channel. BTCs upstream (first 1400 m) had receding...