After three decades of active research coupling hydrology and stream ecology, the connection among solute transport, metabolism and processing is still unresolved. These knowledge gaps obscure the functioning of stream ecosystems and how those ecosystems interact with other landscape processes. We must resolve these challenges to wisely manage water resources,...
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...
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...
The fate of biologically available nitrogen (N) and carbon (C) in stream ecosystems is controlled by the coupling of physical transport and biogeochemical reaction kinetics. However, determining the relative role of physical and biogeochemical controls at different temporal and spatial scales is difficult. The hyporheic zone (HZ), where groundwater–stream water...
After three decades of active research in hydrology and stream ecology, the connection between solute transport, stream metabolism and nutrient dynamics is still unresolved. This existing gap obscures the functionality of stream ecosystems and how they interact with other landscape processes. To date, determining rates of metabolism is accomplished with...
Groundwater–surface-water (GW-SW) interactions in streams are difficult to quantify because of heterogeneity in hydraulic and reactive processes across a range of spatial and temporal scales. The challenge of quantifying these interactions has led to the development of several techniques, from centimeter-scale probes to whole-system tracers, including chemical, thermal, and electrical...
In recent years, our ecological knowledge of tropical dry forests has increased dramatically. However, whole components of the ecosystem, like lichenized fungi, remain mostly unknown. Crustose lichens in these forests are so abundant, that they are responsible for the characteristic appearance of a “white bark forest” during the dry season....
Agave salmiana is a native plant species harvested for the commercial production of mezcal (Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were...
Mountain environments are currently among the ecosystems least invaded by non-native
species; however, mountains are increasingly under threat of non-native plant invasion.
The slow pace of exotic plant invasions in mountain ecosystems is likely due to a combination
of low anthropogenic disturbances, low propagule supply, and extreme/steep environmental
gradients. The...
Mountain environments are currently among the ecosystems least invaded by non-native
species; however, mountains are increasingly under threat of non-native plant invasion.
The slow pace of exotic plant invasions in mountain ecosystems is likely due to a combination
of low anthropogenic disturbances, low propagule supply, and extreme/steep environmental
gradients. The...
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, Catherine G. Parks3, Bridgett J. Naylor3,
Tim DelCurto1, Ricardo Mata-González4
1 Eastern Oregon