title: Shifts in lake N:P stoichiometry and nutrient limitation driven by atmospheric nitrogen deposition.
abstract: Human activities have more than doubled the amount of nitrogen (N) circulating in the biosphere. One major pathway of this anthropogenic N input into ecosystems has been increased regional deposition from the atmosphere. Here we show that atmospheric N deposition increased the stoichiometric ratio of N and phosphorus (P) in lakes in Norway, Sweden, and Colorado, United States, and, as a result, patterns of ecological nutrient limitation were shifted. Under low N deposition, phytoplankton growth is generally N-limited; however, in high-N deposition lakes, phytoplankton growth is consistently P-limited. Continued anthropogenic amplification of the global N cycle will further alter ecological processes, such as biogeochemical cycling, trophic dynamics, and biological diversity, in the world's lakes, even in lakes far from direct human disturbance.
authors.affiliation: School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA. j.elser@asu.edu
authors.forename: James J
authors.initials: JJ
authors.lastname: Elser
authors.forename: Tom
authors.initials: T
authors.lastname: Andersen
authors.forename: Jill S
authors.initials: JS
authors.lastname: Baron
authors.forename: Ann-Kristin
authors.initials: AK
authors.lastname: Bergström
authors.forename: Mats
authors.initials: M
authors.lastname: Jansson
authors.forename: Marcia
authors.initials: M
authors.lastname: Kyle
authors.forename: Koren R
authors.initials: KR
authors.lastname: Nydick
authors.forename: Laura
authors.initials: L
authors.lastname: Steger
authors.forename: Dag O
authors.initials: DO
authors.lastname: Hessen
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D044822:Biodiversity; D018533:Biomass; D003120:Colorado; D017753:Ecosystem; D020387:Food Chain; D005618:Fresh Water / Q000737:chemistry*; D006802:Human Activities; D006801:Humans; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D009664:Norway; D010758:Phosphorus / Q000032:analysis*; D010839:Phytoplankton / Q000254:growth & development / Q000502:physiology*; D013548:Sweden; D014197:Trees
chemical_list: D009566:Nitrates; D010758:Phosphorus; D009584:Nitrogen