title: Relating root structure and anatomy to whole-plant functioning in 14 herbaceous Mediterranean species.
abstract: This study investigated the relationships between root structure and anatomy and whole-plant functioning in herbaceous species. Fourteen annual and perennial species representative of a Mediterranean old-field succession were grown in monocultures in a common-garden experiment. Whole-plant functioning was assessed by inherent relative growth rate (RGR(max)), measured in standardized conditions, and maximum height (H(max)). Root tissue density (TMD(r)), considered as a major component of root structure, was measured on roots harvested within in-growth cores. Anatomical characteristics were analysed on cross-sectional areas (CSA). TMD(r) was correlated positively with H(max) and negatively with RGR(max). Root CSA explained interspecific variation in H(max) but not that in TMD(r) and RGR(max). Root xylem CSA and xylem proportion in root CSA were positively correlated with TMD(r) and H(max) and negatively with RGR(max). Mean xylem vessel CSA did not account for variations in TMD(r), H(max) and RGR(max). These results suggested that RGR(max) and H(max) are constrained by opposite root structural and anatomical traits, which have potential links with hydraulic conductance, support and longevity.
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, UMR 5175, 1919 Route de Mende, 34293 Montpellier Cedex 5, France.
authors.forename: Irène
authors.initials: I
authors.lastname: Hummel
authors.forename: Denis
authors.initials: D
authors.lastname: Vile
authors.forename: Cyrille
authors.initials: C
authors.lastname: Violle
authors.forename: Jeremy
authors.initials: J
authors.lastname: Devaux
authors.forename: Benoît
authors.initials: B
authors.lastname: Ricci
authors.forename: Alain
authors.initials: A
authors.lastname: Blanchard
authors.forename: Eric
authors.initials: E
authors.lastname: Garnier
authors.forename: Catherine
authors.initials: C
authors.lastname: Roumet
mesh_terms: D019684:Magnoliopsida / Q000033:anatomy & histology* / Q000254:growth & development; D019083:Mediterranean Region; D018517:Plant Roots / Q000033:anatomy & histology* / Q000254:growth & development; D013045:Species Specificity