human activity has greatly changed nitrogen cycling and dynamics worldwide.
ecosystem, nitrogen cycle, global nitrogen cycling, nutrient loading, nitrogen saturation of forests.
replot the data, essay quiz, newspaper article
Charlene D'Avanzo, School of Natural Sciences, Hampshire College, Amherst, MA, 01002, firstname.lastname@example.org.
Courtesy of Howard Glasgow, JoAnn Burkholder, NCSU