Study
Trends in wood density and structure are linked to prevention of xylem implosion by negative pressure
Hacke, U. G.; Sperry, J. S.; Pockman, W. T.; Davis, S. D.; McCulloh, K. A.
Oecologia, 2001
Wood density, conduit wall thickness relative to conduit diameter, and the tension at which conduits failed were measured across species from contrasting climates, and the three were compared against one another.
- Studied in
- Pinaceae, Cupressaceae, Fagaceae
- Sample size
- woody species spanning conifers and angiosperms
Species that routinely experience the most negative pressures build thicker conduit walls relative to conduit width, and denser wood overall. The relationship holds across conifers and flowering plants, which build their conduits in quite different ways.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Wood density in many species is explained by the mechanical requirement to resist implosion of water-conducting cells under tension, rather than by support of the stem alone.
How NatureHQ reads it
It answers a question readers ask without realising it is a question: why is some wood heavy? Part of the answer is that a pipe holding water at large negative pressure is being squeezed from outside by the atmosphere, and must be built not to collapse. Dense tropical hardwood and light balsa are, among other things, two different answers about how much tension the tree expects its plumbing to survive.
- A correlation across species, with the mechanism inferred from mechanics rather than demonstrated by manipulation.
- Wood density also carries mechanical support, defence and storage functions, which are not separated here.
- Sampling is weighted towards temperate and Mediterranean floras.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Springer journalsPublished in a Springer journal.
This reference was resolved automatically against Crossref and OpenAlex on 2026-08-30.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-30.