title: The role of plant traits and their plasticity in the response of pasture grasses to nutrients and cutting frequency.
abstract: OBJECTIVE
  Although plant functional traits (PFTs) appear to be important indicators of species' responses to land use changes, there is no clear understanding of how the variations in traits and their plasticity determine variations in species performance. This study investigated the role of functional shoot traits and their plasticity for variation in above-ground net primary productivity (ANPP) due to changes in N supply and in cutting frequency for 13 native perennial C(3) grass species.
  
  
  METHODS
  Monocultures of the grass species were grown in a fully factorial block design combining plant species, cutting frequency and N supply as factors.
  
  
  RESULTS
  Four major trait associations were obtained by reducing the dimensions of 14 PFTs with a principal component analysis (PCA).Variations in species' productivity in response to an increase in cutting frequency was mainly explained by traits linked to the first PCA axis, opposing high plant stature from lower shoot cellulose and lignin contents and high leaf N content. Variation in species productivity in response to change in N supply was mainly explained by a set of predictor variables combining traits (average flowering date) and a trait's plasticity (tiller density per unit land area and leaf dry matter content, i.e. mg dry matter g fresh mass(-1)). These traits involved are linked to the second PCA axis ('nutrient acquisition-conservation'), which opposes distinct strategies based on response to nutrient supply.
  
  
  CONCLUSIONS
  Variations in ANPP of species in response to an increase in cutting frequency and a decrease in N supply are controlled by a group of traits, rather than by one individual trait. Incorporating plasticity of the individual traits into these trait combinations was the key to explaining species' productivity responses, accounting for up to 89 % of the total variability in response to the changes in N supply.
authors.affiliation: Institut National de la Recherche Agronomique UR874, Unité de Recherche sur l'Ecosystème Prairial, Clermont-Ferrand, France. aisepontes@iapar.br
authors.forename: Laíse
authors.initials: L
authors.lastname: da Silveira Pontes
authors.forename: Frédérique
authors.initials: F
authors.lastname: Louault
authors.forename: Pascal
authors.initials: P
authors.lastname: Carrère
authors.forename: Vincent
authors.initials: V
authors.lastname: Maire
authors.forename: Donato
authors.initials: D
authors.lastname: Andueza
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Soussana
mesh_terms: D001673:Biodegradation, Environmental; D044822:Biodiversity; D002980:Climate; D017753:Ecosystem; D035264:Flowers / Q000502:physiology; D010641:Phenotype; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology; D018520:Plant Shoots / Q000502:physiology; D018547:Plant Stems / Q000502:physiology; D006109:Poaceae / Q000502:physiology*; D011157:Population Dynamics; D013045:Species Specificity; D013696:Temperature