Open AccessU.S. nitrogen science plan focuses collaborative efforts
Author(s) -
Holland E. A.,
Guenther A.,
LeeTaylor J.,
Bertman S. B.,
Carroll M. A.,
Shepson P. B.,
Sparks J. P.
Publication year - 2005
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/2005eo270001
Subject(s) - reactive nitrogen , environmental science , nitrogen , environmental chemistry , tropospheric ozone , nitrous oxide , greenhouse gas , ecosystem , nitrogen cycle , ozone , biogeochemistry , terrestrial ecosystem , carbon sequestration , nitrogen dioxide , chemistry , ecology , organic chemistry , biology
Nitrogen is a major nutrient in terrestrial ecosystems and an important catalyst in tropospheric photochemistry. Over the last century human activities have dramatically increased inputs of reactive nitrogen (N r , the combination of oxidized, reduced, and organically bound nitrogen) to the Earth system (Figure 1). Nitrogen cycle perturbations have compromised air quality and human health, acidified ecosystems, and degraded and eutrophied lakes and coastal estuaries [ Vitousek et al ., 1997a, 1997b; Rabalais , 2002; Howarth et al ., 2003; Townsend et al ., 2003; Galloway et al ., 2004]. Increased N r affects global climate. Use of agricultural fertilizers such as ammonium nitrate leads to increased soil production of nitrous oxide (N 2 O), which has 320 times the global warming potential of carbon dioxide (CO 2 ). Emission of nitrogen oxides (NO x = nitric oxide, NO + nitrogen dioxide, NO 2 ) from fossil fuel burning leads to increases in tropospheric ozone, another greenhouse gas. Ozone is phytotoxic, and may reduce terrestrial CO 2 sequestration. To predict the effects of nitrogen cycling changes under changing climatic conditions, there needs to be a better understanding of the global nitrogen budget.