title: Allometric analysis reveals relatively little variation in nitrogen versus biomass accrual in four plant species exposed to varying light, nutrients, water and CO2.
abstract: Nitrogen concentrations in plant tissues can vary as a function of resource availability. Altered rates of plant growth and development under varying resource availabilities were examined to determine their effects on changes in whole-plant N use efficiency (NUE). Three species of old-field annuals were grown at broadly varying light, nutrient and water levels, and four species at varying atmospheric concentrations of CO2. Study results show highly variable N accrual rates when expressed as a function of plant age or size, but similar patterns of whole-plant N versus non-N biomass accrual over a wide range of environmental conditions. However, severely light-limited plants showed increased N versus biomass accrual for two of three species, and severely nutrient-limited plants had decreased N versus biomass accrual for all species. Whole-plant N accrual versus age and N versus biomass accrual increased under saturating water for two of three species. A marginally significant, modest decrease in N versus biomass accrual was found at high CO2 levels for two of four species. Physiological adjustments in NUE, expressed as N versus biomass accrual, were limited to environments with severely limited or overabundant resources.
authors.affiliation: Department of Biology, Olin Hall, Bradley University, Peoria, IL 61625, USA.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Bernacchi
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Thompson
authors.forename: James S
authors.initials: JS
authors.lastname: Coleman
authors.forename: Kelly D M
authors.initials: KD
authors.lastname: McConnaughay
mesh_terms: D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism*; D005308:Fertilizers; D008027:Light; D019684:Magnoliopsida / Q000033:anatomy & histology / Q000378:metabolism* / Q000528:radiation effects*; D009584:Nitrogen / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D005308:Fertilizers; D014867:Water; D002245:Carbon Dioxide; D009584:Nitrogen