Continentalscale climatic drivers of growth ring

Authors: David M J S Bowman Lynda D Prior David Y P Tng Quan Hua Timothy J Brodribb

Publish Date: 2011/04/24

Volume: 25, Issue: 5, Pages: 925-934

PDF Link

Abstract

Callitris is Australia’s most successful and drought tolerant conifer genus Callitris species are distributed across a huge geographical range from rainforest to arid zones and hence they provide a rare opportunity to view plant growth trends across the continent Here we make a continentalscale examination of how climate influences basal diameter growth in Callitris We sampled a total of five species but focused effort 23 of 28 samples on the most widespread species C columellaris Cores from a total of 23 trees were sampled from 15 sites that spanned a gradient in mean annual rainfall from 225 to 2117 mm and mean annual temperature from 115 to 282°C Ring production is not annual across much of the distribution of the genus so 14CAMS dating was used to establish the frequency of ring production for each core Ring width tracheid lumen diameter and number of tracheids per ring were also measured on each core Ring production was close to annual at mesic sites with reliable alternation of rainfall or temperature regimes but was more erratic elsewhere For C columellaris ring width significantly increased with mean annual rainfall r2 = 049 as a result of wider and more tracheids per ring For this species tracheid lumen diameter was correlated with annual rainfall r2 = 061 with a threefold increase from the driest to the wettest sites lending support to the hypothesis that conifers growing at drier sites will have narrow lumen diameters to maximise mechanical strength of the xylemWe thank Scott Nichols Phillip Moser Diane Prior Lachie McCaw Kim Whitford Richard Fairman Sharyn Yelverton Herman Mouthaan Stephen Harris Kim Webeck Kathryn Allen and Stuart Kate Lily and Ted Pearson for field assistance Rob Argent Melbourne Water collected the Snowy River sample Scott Nichols and Kathryn Allen prepared the cores and Zoe Lee helped in sample processing for AMS 14C analysis Gregor Sanders prepared the map This project received funding from CERF grant B0016193 Radiocarbon analysis was funded with grants from the Australian Institute of Nuclear Science and Engineering Grants 00/122 03/090P and 07/014 We thank the Northern Territory Parks and Wildlife Service NSW Department of Environment and Climate Change Queensland Department of Environment and Resource Management WA Department of Environment and Conservation Victorian Department of Sustainability and Environment Parks and Wildlife Service Tasmania the Consolidated Pastoral Company Mr Garth Dunford the Siemer family and the Australian Wildlife Conservancy for help with site selection and permission to sample on their land

Keywords: