This study examines dissolved rhenium (Re) as a function of water runoff using river samples from two contrasting watersheds, the Eel and Umpqua Rivers in the Pacific Northwest, USA. These watersheds share many key characteristics in terms of size, discharge, climate, and vegetation, but they have a 10-fold difference in...
Dust deposition on ecosystems with highly weathered soils may provide vital rock-derived nutrients that maintain ecosystem productivity. Because of the difficulties in measuring temporally and spatially heterogeneous dust deposition over ecologically meaningful timescales, evaluations of the spatial variability in dust deposition are extremely rare. In the Luquillo Mountains of Puerto...
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...
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....
Nutrient limitation constrains tree growth in many managed forests. Nitrogen (N) is the most common limiting nutrient, but high N supply can shift limitation to other nutrients, particularly phosphorus (P) and the base cations calcium (Ca), magnesium (Mg), and potassium (K). As different soil minerals have different capacities to supply...
In order to determine how contaminants from pharmaceutical, agriculture, and industry will move through groundwater systems, it is imperative to further our understanding of the relationship between physical, biological, and chemical properties of aquifers and transport and transformation of these products. Several studies have explored how heterogeneities in groundwater systems...