Anthropologic activities have transformed global biogeochemical cycling of heavy metals by
emitting considerable quantities of these metals into the atmosphere from diverse sources …

Nitrate (NO3−) concentrations in public water supplies have risen above acceptable levels
in many areas of the world, largely as a result of overuse of fertilizers and contamination by …

Many chemical reactions at the Earth's surface are influenced by biota. Ecosystem
ecologists study the flow of matter and energy in ecosystems composed of organisms and …

Despite the potential use of δ15N as a tracer of NO x source contributions, prior
documentation of δ15N of various NO x emission sources is exceedingly limited. This …

Global inputs of NO x are dominated by fossil fuel combustion from both stationary and
vehicular sources and far exceed natural NO x sources. However, elucidating NO x sources …

Quantifying contributions of local and regional NO x emission sources is an important initial
step towards accurately assessing improvements in NO x emission reduction efforts. Current …

The nitrogen stable isotope ratio of NO x (δ15N-NO x) has been proposed as a regional
indicator for NO x source partitioning; however, knowledge of δ15N values from various NO …

The nitrogen stable isotope composition of NO x (δ15N-NO x) may be a useful indicator for
NO x source partitioning, which would help constrain NO x source contributions in nitrogen …

Dry deposition is a major component of total atmospheric nitrogen deposition and thus an
important source of bioavailable nitrogen to ecosystems. However, relative to wet …

Alteration of the global nitrogen (N) cycle because of human‐enhanced N fixation is a major
concern particularly for those ecosystems that are nutrient poor by nature. Because …