title: Assessment of effects of the rising atmospheric nitrogen deposition on nitrogen uptake and long-term water-use efficiency of plants using nitrogen and carbon stable isotopes.
abstract: This study assesses the effects of the atmospheric nitrogen (N) deposition on the N uptake and the long-term water-use efficiency of two C(3) plants (Agropyron cristatum and Leymus chinensis) and two C(4) plants (Amaranthus retroflexus and Setaria viridis) using N and C stable isotopes. In addition, this study explores the potential correlation between leaf N isotope (δ(15)N) values and leaf C isotope (δ(13)C) values. This experiment shows that the atmospheric N deposition has significant effects on the N uptake, δ(15)N and leaf N content (N(m)) of C(3) plants. As the atmospheric N deposition rises, the proportion and the amount of N absorbed from the simulated atmospheric deposition become higher, and the δ(15)N and N(m) of the two C(3) plants both also increase, suggesting that the rising atmospheric N deposition is beneficial for C(3) plants. However, C(4) plants display different patterns in their N uptake and in their variations of δ(15)N and N(m) from those of C(3) plants. C(4) plants absorb less N from the atmospheric deposition, and the leaf N(m) does not change with the elevated atmospheric N deposition. Photosynthetic pathways may account for the differences between C(3) and C(4) plants. This study also shows that atmospheric N deposition does not play a role in determining the δ(13)C and in the long-term water-use efficiency of C(3) and C(4) plants, suggesting that the long-term water-use pattern of the plants does not change with the atmospheric N input. In addition, this study does not observe any relationship between leaf δ(15)N and leaf δ(13)C in both C(3) and C(4) plants.
authors.affiliation: Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: F Y
authors.initials: FY
authors.lastname: Yao
authors.forename: G A
authors.initials: GA
authors.lastname: Wang
authors.forename: X J
authors.initials: XJ
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Song
mesh_terms: D027721:Amaranthus / Q000378:metabolism*; D000704:Analysis of Variance; D001272:Atmosphere / Q000737:chemistry*; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D009587:Nitrogen Isotopes / Q000032:analysis / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D006109:Poaceae / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D014867:Water; D009584:Nitrogen