Xylem hydraulic characteristics of subtropical trees from contrasting habitats grown under identical environmental conditions

• Published in: The New phytologist Vol. 145; no. 1; pp. 51 - 59
• Main Authors: VANDER WILLIGEN, C., SHERWIN, H. W., PAMMENTER, N. W.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.01.2000; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Angiosperms; Barringtonia; barringtonia racemosa; Biological and medical sciences; biological resistance; Branches; cavitation; Cavitation flow; Cinnamomum camphora; Data lines; Economic plant physiology; embolism; Fundamental and applied biological sciences. Psychology; genetic variation; genotype; habitats; hydraulic architecture; Hydraulic conductivity; Hydraulics; leaf area; leaf conductance; Magnoliophyta; mathematical models; phenotype; phenotypic variation; plant anatomy; Plant physiology and development; plant vascular system; Plants; Podocarpus; podocarpus latifolius; subtropics; tecomaria capensis; Transpiration; Trees; Trichilia; trichilia dregeana; vulnerability curve; Water and solutes. Absorption, translocation and permeability; water potential; water relations; Water relations, transpiration, stomata; Xylem; South Africa; xylem; hydraulic conductivity; transpiration; water relations; hydraulic architecture; vulnerability curve; embolism; cavitation; Climate; Xylem; Essential oil plant; Interspecific comparison; Environmental factor; Hydraulic conductivity; Coniferous ornamental tree; Meliaceae; Cavitation; Embolism; Genotype environment interaction; Water regime; Dicotyledones; Angiospermae; Gymnospermae; Evapotranspiration; Coniferales; Spermatophyta; Habitat; Bignoniaceae; Lauraceae
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1046/j.1469-8137.2000.00549.x

Five evergreen subtropical tree species growing under identical environmental conditions were investigated to establish which hydraulic properties are genotypically rigid and which show phenotypic plasticity. Maximum xylem-specific conductivity (ks) correlated well with the anatomical characteristics (conduit diameter and density) for the four angiosperms Tecomaria capensis, Trichilia dregeana, Cinnamomum camphora and Barringtonia racemosa; the anatomy of the gymnosperm Podocarpus latifolius was not assessed. Huber values (functional xylem cross-sectional area [ratio ] leaf area) varied inversely with ks among species. Maximum leaf-specific conductivity was similar in the five unrelated species. Vulnerability of xylem to cavitation differed between species, as did the relationship between transpiration and water potential. Models of these parameters and isolated midday readings confirm that these trees operate at similar maximum leaf-specific conductivity (kl) values. The data are consistent with the hypothesis that conductivity characteristics (kl, ks) are influenced by environment, whereas vulnerability to cavitation is genetically determined.