title: Meaningful traits for grouping plant species across arid ecosystems.
abstract: Grouping species may provide some degree of simplification to understand the ecological function of plants on key ecosystem processes. We asked whether groups of plant species based on morpho-chemical traits associated with plant persistence and stress/disturbance resistance reflect dominant plant growth forms in arid ecosystems. We selected twelve sites across an aridity gradient in northern Patagonia. At each site, we identified modal size plants of each dominant species and assessed specific leaf area (SLA), plant height, seed mass, N and soluble phenol concentration in green and senesced leaves at each plant. Plant species were grouped according with plant growth forms (perennial grasses, evergreen shrubs and deciduous shrubs) and plant morphological and/or chemical traits using cluster analysis. We calculated mean values of each plant trait for each species group and plant growth form. Plant growth forms significantly differed among them in most of the morpho-chemical traits. Evergreen shrubs were tall plants with the highest seed mass and soluble phenols in leaves, deciduous shrubs were also tall plants with high SLA and the highest N in leaves, and perennial grasses were short plants with high SLA and low concentration of N and soluble phenols in leaves. Grouping species by the combination of morpho-chemical traits yielded 4 groups in which species from one growth form prevailed. These species groups differed in soluble phenol concentration in senesced leaves and plant height. These traits were highly correlated. We concluded that (1) plant height is a relevant synthetic variable, (2) growth forms adequately summarize ecological strategies of species in arid ecosystems, and (3) the inclusion of plant morphological and chemical traits related to defenses against environmental stresses and herbivory enhanced the potential of species grouping, particularly within shrubby growth forms.
authors.affiliation: Instituto Patagónico para el Estudio de los Ecosistemas Continentales (CENPAT-CONICET), Boulevard Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina. barlamas@cenpat-conicet.gob.ar.
authors.forename: Marlene Ivonne
authors.initials: MI
authors.lastname: Bär Lamas
authors.affiliation: Instituto Patagónico para el Estudio de los Ecosistemas Continentales (CENPAT-CONICET), Boulevard Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina.|Universidad Nacional de la Patagonia San Juan Bosco, Boulevard Brown 3700, U9120ACD, Puerto Madryn, Chubut, Argentina.
authors.forename: A L
authors.initials: AL
authors.lastname: Carrera
authors.affiliation: Instituto Patagónico para el Estudio de los Ecosistemas Continentales (CENPAT-CONICET), Boulevard Brown 2915, U9120ACD, Puerto Madryn, Chubut, Argentina.|Universidad Nacional de la Patagonia San Juan Bosco, Boulevard Brown 3700, U9120ACD, Puerto Madryn, Chubut, Argentina.
authors.forename: M B
authors.initials: MB
authors.lastname: Bertiller
mesh_terms: D018533:Biomass; D003889:Desert Climate; D017753:Ecosystem; D005843:Geography; D009584:Nitrogen / Q000032:analysis; D010636:Phenols / Q000032:analysis; D063245:Plant Development; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development; D010944:Plants / Q000033:anatomy & histology / Q000145:classification*; D019655:Quantitative Trait, Heritable; D012995:Solubility; D013045:Species Specificity
chemical_list: D010636:Phenols; D009584:Nitrogen
keywords: Desert plants; N concentration; Plant height; Seed mass; Soluble phenols; Specific leaf area