Data from: Biophysical dependences among functional wood traits

1. Wood properties and especially wood density have been used as
functional traits organized along major axes of species life history and
strategy. Beyond statistical analyses, a better mechanistic understanding
of relationships among wood traits is essential for ecologically relevant
interpretation of wood trait variations. 2. A set of theoretical
relationships mechanistically linking wood basic density with some other
wood traits is derived from cellular material physics. These theoretical
models picture basic physical constraints and thus provide null-hypotheses
for further ecological studies. Analysis is applied to data from two
original datasets and several datasets extracted from literature. 3.
Results emphasize the strong physical constraint behind the link between
basic density and maximal storable water on the one hand, and elastic
modulus on the other hand. Beyond these basic physical constraints, the
developed framework reveals physically less expected trends: the amount of
free water available for physiological needs increases in less dense wood
of fast growing species, the cell wall stiffness decreases with density in
temperate species and is higher in sapling stages in the rainforest
understorey where competition for light is associated to high mechanical
risk. 4. We emphasize the use of theoretically independent traits derived
from models of cellular material physics to investigate the functional
variation of wood traits together with their environmental and
phylogenetic variations. Although the current study is limited to basic
density, green wood lumen saturation and wood specific modulus, we further
emphasize the identification of complementary independent wood traits
representing other biomechanical functions, nutrient storage, hydraulic
conductance and resistance to drought.