title: Trait convergence and plasticity among native and invasive species in resource-poor environments.
abstract: OBJECTIVE
  Functional trait comparisons provide a framework with which to assess invasion and invasion resistance. However, recent studies have found evidence for both trait convergence and divergence among coexisting dominant native and invasive species. Few studies have assessed how multiple stresses constrain trait values and plasticity, and no study has included direct measurements of nutrient conservation traits, which are critical to plants growing in low-resource environments.
  
  
  METHODS
  We evaluated how nutrient and water stresses affect growth and allocation, water potential and gas exchange, and nitrogen (N) allocation and use traits among a suite of six codominant species from the Intermountain West to determine trait values and plasticity. In the greenhouse, we grew our species under a full factorial combination of high and low N and water availability. We measured relative growth rate (RGR) and its components, total biomass, biomass allocation, midday water potential, photosynthetic rate, water-use efficiency (WUE), green leaf N, senesced leaf N, total N pools, N productivity, and photosynthetic N use efficiency.
  
  
  RESULTS
  Overall, soil water availability constrained plant responses to N availability and was the major driver of plant trait variation in our analysis. Drought decreased plant biomass and RGR, limited N conservation, and led to increased WUE. For most traits, native and nonnative species were similarly plastic.
  
  
  CONCLUSIONS
  Our data suggest native and invasive biomass dominants may converge on functionally similar traits and demonstrate comparable ability to respond to changes in resource availability.
authors.affiliation: Biology Department, John Carroll University 20700 North Park Blvd., University Heights, Ohio 44118, USA. rdrenovsky@jcu.edu
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Drenovsky
authors.forename: Albina
authors.initials: A
authors.lastname: Khasanova
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: James
mesh_terms: D018533:Biomass; D004777:Environment; D005740:Gases / Q000378:metabolism; D058865:Introduced Species; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis; D010944:Plants / Q000378:metabolism*; D025341:Principal Component Analysis; D019655:Quantitative Trait, Heritable; D013223:Statistics as Topic; D014867:Water
chemical_list: D005740:Gases; D014867:Water; D009584:Nitrogen