title: Leaf size serves as a proxy for xylem vulnerability to cavitation in plantation trees.
abstract: Hybrid poplars are an important renewable forest resource known for their high productivity. At the same time, they are highly vulnerable to water stress. Identifying traits that can serve as indicators for growth performance remains an important task, particularly under field conditions. Understanding which trait combinations translate to improved productivity is key in order to satisfy the demand for poplar wood in an uncertain future climate. In this study, we compared hydraulic and leaf traits among five hybrid poplar clones at 10 plantations in central Alberta. We also assessed the variation of these traits between 2- to 3-year-old branches from the lower to mid-crown and current-year long shoots from the mid to upper crown. Our results showed that (1) hybrid poplars differed in key hydraulic parameters between branch type, (2) variation of hydraulic traits among clones was relatively large for some clones and less for others, and (3) strong relationships between measured hydraulic traits, such as vessel diameter, cavitation resistance, xylem-specific and leaf-specific conductivity and leaf area, were observed. Our results suggest that leaf size could serve as an additional screening tool when selecting for drought-tolerant genotypes in forest management and tree improvement programmes.
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada, T6G 2E3.
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Schreiber
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada, T6G 2E3.
authors.forename: Uwe G
authors.initials: UG
authors.lastname: Hacke
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada, T6G 2E3.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Chamberland
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada, T6G 2E3.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Lowe
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada, T6G 2E3.
authors.forename: David
authors.initials: D
authors.lastname: Kamelchuk
authors.affiliation: Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada, M1C 1A4.
authors.forename: Katharina
authors.initials: K
authors.lastname: Bräutigam
authors.affiliation: Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada, M1C 1A4.|Centre for the Analysis of Genome Evolution and Function, University of Toronto, 25 Willcocks St., Toronto, Ontario, Canada, M5S 3B2.|Department of Molecular and Cellular Biology, University of Guelph, Summerlee Science Complex, Guelph, Ontario, Canada, N1G 2W1.
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: Campbell
authors.affiliation: Department of Renewable Resources, University of Alberta, 442 Earth Sciences Building, Edmonton, Alberta, Canada, T6G 2E3.
authors.forename: Barb R
authors.initials: BR
authors.lastname: Thomas
mesh_terms: D005843:Geography; D009929:Organ Size; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000502:physiology*; D018520:Plant Shoots / Q000502:physiology; D019655:Quantitative Trait, Heritable; D014197:Trees / Q000502:physiology*; D014867:Water; D052584:Xylem / Q000502:physiology*
chemical_list: D014867:Water
keywords: boreal forest; cavitation; drought stress; forest management; leaf area; plant hydraulics; plasticity; poplar plantations; water transport