Abstract
ObjectivesJust as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications.MethodsTwig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38–0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity).ResultsDespite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P < 0.001). Parenchyma was weakly (0.24 ≤|r|≤ 0.35, P < 0.05) or not associated with vessel properties nor with height, leaf area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P < 0.05). However, vessel traits were fairly well correlated with height and leaf area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P < 0.001). Modulus of elasticity was mainly driven by fibre wall plus vessel wall fraction rather than by the parenchyma component.ConclusionsOverall, there seem to be at least three axes of variation in xylem, substantially independent of each other: a wood density spectrum, a fibre-parenchyma spectrum, and a vessel area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation.
Highlights
There are many ways plants make a living, or many ecological ‘strategies’, and the study of plant traits—and their variation among species—is a key way of gaining insight into these [1,2,3]
Vessel traits were fairly well correlated with height and leaf area to sapwood area ratio (0.47 |r| 0.65, all P < 0.001)
Modulus of elasticity was mainly driven by fibre wall plus vessel wall fraction rather than by the parenchyma component
Summary
There are many ways plants make a living, or many ecological ‘strategies’, and the study of plant traits—and their variation among species—is a key way of gaining insight into these [1,2,3]. Some strategies tend to be related to wood density (g cm-3; [4]), but plausibly there are strategies related to wood properties that are independent of density. On the basis that density is directly determined by anatomical structure, several studies have searched for links between density and anatomy [5,6,7,8,9,10,11,12,13]. Variation in wood density across species has proved to be mainly driven by fibre wall and fibre lumen properties (e.g. fibre wall and lumen fractions), more so than by the fraction of wood that is vessels [5,6,7,8,12,13,14], creating one dimension of ecological trait variation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
