A5020706213- Atmospheric chemistry and aerosols
- Soil and Water Nutrient Dynamics
- Marine and coastal ecosystems
- Groundwater and Isotope Geochemistry
- Atmospheric and Environmental Gas Dynamics
- Phosphorus and nutrient management
- Atmospheric Ozone and Climate
- Agriculture Sustainability and Environmental Impact
- Environmental Impact and Sustainability
- Water Quality and Resources Studies
- Wastewater Treatment and Nitrogen Removal
- Soil Carbon and Nitrogen Dynamics
- Climate Change Policy and Economics
- Air Quality and Health Impacts
- Peatlands and Wetlands Ecology
- Water Quality and Pollution Assessment
- Crop Yield and Soil Fertility
- Isotope Analysis in Ecology
- Odor and Emission Control Technologies
- Atmospheric aerosols and clouds
- Ocean Acidification Effects and Responses
- Heavy metals in environment
- Fish Ecology and Management Studies
- Water-Energy-Food Nexus Studies
- Nutritional Studies and Diet
University of Virginia
2015-2024
McCormick (United States)
2004-2024
Leibniz Institute of Freshwater Ecology and Inland Fisheries
2024
University of New Hampshire
1995-2020
Charlottesville Medical Research
1984-2014
Institute of Molecular and Cell Biology
2009
Institute of Arctic and Alpine Research
2008
University of Colorado Boulder
2008
Energy Research Centre of the Netherlands
2003-2008
Makerere University
2008
Global Biodiversity Target Missed In 2002, the Convention on Biological Diversity (CBD) committed to a significant reduction in rate of biodiversity loss by 2010. There has been widespread conjecture that this target not met. Butchart et al. (p. 1164 , published online 29 April) analyzed over 30 indicators developed within CBD's framework. These include condition or state (e.g., species numbers, population sizes), pressures deforestation), and responses maintain protected areas) were...
Human production of food and energy is the dominant continental process that breaks triple bond in molecular nitrogen (N2) creates reactive (Nr) species. Circulation anthropogenic Nr Earth’s atmosphere, hydrosphere, biosphere has a wide variety consequences, which are magnified with time as moves along its biogeochemical pathway. The same atom can cause multiple effects terrestrial ecosystems, freshwater marine systems, on human health. We call this sequence cascade. As cascade progresses,...
Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe North America. This paper assesses evidence from field experiments for N effects thresholds terrestrial protection across latitudinal range main categories ecosystems, arctic boreal systems tropical forests. Current thinking on the mechanisms diversity, global distribution G200 ecoregions, current future (2030) estimates atmospheric N-deposition rates are then used identify...
Over the past decade it has become apparent that atmosphere is a significant pathway for transport of many natural and pollutant materials from continents to ocean. The atmospheric input these species can have an impact (either positive or negative) on biological processes in sea marine chemical cycling. For example, there now evidence may be important path such essential nutrients as iron nitrogen some regions. In this report we assess current data area, develop global scale estimates...
We use 23 atmospheric chemistry transport models to calculate current and future (2030) deposition of reactive nitrogen (NO y , NH x ) sulfate (SO land ocean surfaces. The are driven by three emission scenarios: (1) air quality legislation (CLE); (2) an optimistic case the maximum emissions reductions currently technologically feasible (MFR); (3) contrasting pessimistic IPCC SRES A2 scenario. An extensive evaluation present‐day using nearly all information on wet available worldwide shows a...
In the absence of human activities, biotic fixation is primary source reactive N, providing about 90–130 Tg N yr −1 (Tg = 10 12 g) on continents. Human activities have resulted in an additional ≈140 by energy production (≈20 ), fertilizer (≈80 and cultivation crops (e.g., legumes, rice) (≈40 ). We can only account for part this anthropogenic N. 2 O accumulating atmosphere at a rate 3 . Coastal oceans receive another 41 via rivers, much which buried or denitrified. Open 18 atmospheric...
The demand for more food is increasing fertilizer and land use, the energy fossil fuel combustion, leading to enhanced losses of reactive nitrogen (N r ) environment. Many thresholds human ecosystem health have been exceeded owing N pollution, including those drinking water (nitrates), air quality (smog, particulate matter, ground-level ozone), freshwater eutrophication, biodiversity loss, stratospheric ozone depletion, climate change coastal ecosystems (dead zones). Each these environmental...
Differentiation of sea‐salt and non‐sea‐salt (or excess) components is essential for many studies marine aerosol precipitation chemistry. Uncertainties in such calculations arise from (1) uncertainties the composition seawater, (2) analytical uncertainties, (3) amount dry deposited sea salt samples, (4) validity assuming a purely source reference species, (5) no fractionation during or after production aerosols. We assessed these and, using reduced major axis regression technique, evaluated...
The Global Precipitation Chemistry Project collects precipitation by event to determine composition and processes controlling it in five remote areas. Compositions (excluding sea‐salt) at St. Georges, Bermuda, were primarily controlled anthropogenic processes; compositions acidities San Carlos, Venezuela, Katherine, Australia, Poker Flat, Alaska, Amsterdam Island unknown mixtures of natural or processes. was acidic; average volume‐weighted pH values 4.8 for Bermuda; 5.0, Alaska; 4.9, Island;...
Quantitative predictions of the effects acid deposition onterrestrial and aquatic systems require physically based, process‐oriented models catchment soil water streamwater chemistry. A desirable characteristic such is that they include terms to describe important phenomena controlling a system's chemical response acidic deposition, yet be restricted in complexity so can implemented on diverse with minimum priori data. We present an assessment conceptual model chemistry based cation...
Global meat production is becoming increasingly industrialized, spatially concentrated, and geographically detached from the agricultural land base. This Policy Forum reviews process of livestock industrialization globalization, its consequences for water, nitrogen, species-rich habitats in meat- feed-producing regions often vastly separated space. It argues that pricing other policy mechanisms which reflect social costs resource use ecological change are needed to re-couple producer...
The Global Precipitation Chemistry Project collects precipitation by event to determine the composition of and processes that control it in five remote regions. Ion balances based on major inorganic species revealed consistent anion deficits at certain sites. This other evidence suggested weak organic acids contributed free acidity. Accurate precise techniques were developed measure anions total acidity precipitation. Twelve samples from a site analyzed for chemical constituents. Formic...