Quantification of the transient storage zone (A[subscript s]) has become critical in stream biogeochemical studies addressed to examine factors controlling nutrient uptake. It is expected that higher A[subscript s] may enhance the interaction between nutrients and biota and thus, increase nutrient uptake. However, results from the literature are controversial. We...
We used an in situ steady state ¹⁵N-labeled nitrate (¹⁵NO₃⁻) and acetate (AcO⁻) well-to-wells injection experiment to determine how the availability of labile dissolved organic carbon (DOC) as AcO⁻ influences microbial denitrification in the hyporheic zone of an upland (third-order) agricultural stream. The experimental wells receiving conservative (Cl⁻ and Br)...
Surface and subsurface flow dynamics govern residence time or water age until discharge, which is a key metric of storage and water availability for human use and ecosystem function. Although observations in small catchments have shown a fractal distribution of ages, residence times are difficult to directly quantify or measure...
Surface and subsurface flow dynamics govern residence time or water age until discharge, which is a key metric of storage and water availability for human use and ecosystem function. Although observations in small catchments have shown a fractal distribution of ages, residence times are difficult to directly quantify or measure...
The use of smart tracers to study hydrologic systems is becoming more widespread. Smart tracers are compounds that irreversibly react in the presence of a process or condition under investigation. Resazurin (Raz) is a smart tracer that undergoes an irreversible reduction to resorufin (Rru) in the presence of cellular metabolic...
We monitored a suite of stream chemistry parameters for April and May, 2013, at Oak Creek, Oregon, USA. The dataset can be downloaded at the following URL: http://dx.doi.org/10.7267/N9JW8BSJ, via the Dataset Query Tool. The dataset is hosted by The Oregon Hydrologic Information Server (OHIS), which is an on-line database repository...
We investigated the late-time (asymptotic) behavior of tracer test breakthrough
curves (BTCs) with rate-limited mass transfer( e.g., in dual-porosity or multiporosity
systems) and found that the late-time concentration c is given by the simple expression
C = tₐ𝒹{C₀g-- [m₀(∂g/∂t)]}, for t >> tₐ𝒹 and tα >> tₐ𝒹, where tad is...
We measured the hyporheic residence time distribution in a 2nd-order mountain stream at the H. J. Andrews Experimental Forest, Oregon, and found it to be a power-law over at least 1.5 orders of magnitude in time (1.5 hr to 3.5 d). The residence time distribution has a very long tail...
Water transient storage zones are hotspots for metabolic activity in streams although the contribution of different types of transient storage zones to the whole-reach metabolic activity is difficult to quantify. In this study we present a method to measure the fraction of the transient storage that is metabolically active (MATS)...
Stream functioning includes simultaneous interaction among solute transport, nutrient processing, and metabolism. Metabolism is measured with methods that have limited spatial representativeness and are highly uncertain. These problems restrict development of methods for up-scaling biological processes that mediate nutrient processing. We used the resazurin–resorufin (Raz-Rru) tracer system to estimate metabolism...