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Continental-scale climatic drivers of growth ring variability in an Australian conifer
journal contribution
posted on 2023-05-17, 10:25 authored by David BowmanDavid Bowman, Lynda PriorLynda Prior, Tng, DYP, Hua, Q, Timothy BrodribbTimothy BrodribbCallitris 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 continental-scale 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 11.5 to 28.2 Celsius degree. Ring production is not annual across much of the distribution of the genus, so 14C-AMS 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 = 0.49) as a result of wider and more tracheids per ring. For this species tracheid lumen diameter was correlated with annual rainfall (r2 = 0.61), 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 xylem.
History
Publication title
Trees: Structure and FunctionVolume
25Issue
5Pagination
925-934ISSN
0931-1890Department/School
School of Natural SciencesPublisher
Springer-VerlagPlace of publication
175 Fifth Ave, New York, USA, Ny, 10010Rights statement
Copyright 2011 Springer-Verlag.Repository Status
- Restricted