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Seedling growth in conifers and angiosperms: impacts of contrasting xylem structure

Citation

Brodribb, TJ and Holbrook, NM and Hill, RS, Seedling growth in conifers and angiosperms: impacts of contrasting xylem structure, Australian Journal of Botany, 53, (8) pp. 749-755. ISSN 0067-1924 (2005) [Refereed Article]

DOI: doi:10.1071/BT05049

Abstract

Competitive interaction between conifers and angiosperms has moulded the structure of global vegetation since the Cretaceous. Angiosperms appear to enjoy their greatest advantage in the lowland tropics, an advantage often attributed to the presence of vessels in their xylem tissue. By monitoring the seedling growth of three members of the pan-tropical conifer family Podocarpaceae and three tropical angiosperm tree species, our aim was to determine whether these conifer and angiosperm seedlings showed distinct patterns of growth and light adaptation that might be attributed to the presence/absence of vessels. Angiosperm seedlings were consistently more efficient in terms of leaf area carried per unit stem investment, as well as more responsive to light climate than the conifer seedlings. Apparently linked to this were larger growth rate, stem hydraulic conductivity and stomatal conductance in the angiosperm sample. Stem hydraulic conductivity and maximum stomatal conductance were highly correlated among species and light treatments explaining the association between highly conductive vessel-bearing wood and high rates of gas exchange. We conclude that xylem vessels contribute to higher rates of gas exchange and more efficient production of leaf area in our sample angiosperms than in conifers. However, this advantage is limited by shade. © CSIRO 2005.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Brodribb, TJ (Dr Tim Brodribb)
ID Code:38101
Year Published:2005
Web of Science® Times Cited:17
Deposited By:Plant Science
Deposited On:2005-08-01
Last Modified:2007-12-04
Downloads:0

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