Table 1.
Site details.
Fig 1.
Illustration of wood tissues (A) and the image analysis method applied in this study (B), shown on an example of Gomphandra australiana, Icacinaceae.
(B) Vessels were manually coloured (large circles in dark blue) and then the vessel areas ware measured in image analysis software (see text for details). Grid method was used to estimate tissue fractions. Grid points were marked according to the tissue they fell in: light blue—vessel lumen, purple—vessel wall, red—axial parenchyma, green—ray parenchyma, yellow—fibre lumen and black—fibre wall. For clarity, the picture illustrates only a fragment of a larger, pie-shape area analysed. Scale bar corresponds to 100 μm.
Table 2.
Traits overview.
Fig 2.
Stack bar graph of tissue fractions across 69 species.
Each bar represents an individual species with the top bar representing fractions averaged across all species. Species are sorted in order of decreasing total parenchyma fraction (axial + ray). Numbers on the left side indicate wood density of a given species. Species name, family, and site are given on the right side of the graph. Site codes stand for: R—tropical rainforest (Cape Tribulation), W—tropical woodland (Blencoe Falls) and F—temperate forest (Thredbo).
Fig 3.
Relationship between total fibre fraction and total parenchyma fraction.
Green circles—tropical rainforest (warm and wet site); red squares—tropical woodland (warm and dry site); blue triangles—temperate forest (cool and wet site). *** P < 0.001.
Table 3.
Pairwise correlations among the studied traits.
Fig 4.
Relationship between fibre wall fraction and fibre lumen fraction across 93 species (A) and a diagram illustrating this relationship (B).
(A) Black symbols represent 69 from this study and grey symbols represent 24 species from [12]. Symbol diameter is proportional to species wood density. With the smallest diameter corresponding to the lowest density and the largest diameter to the highest density. Isolines indicate total fibre fraction increasing from left to right by a step of 0.1. Grey numbers above the X axis correspond to total fibre fraction indicated by a given isoline. (B) A diagram illustrating Fig 4A; the diagram is modified from Fig 8 in [12]. The six squares symbolize cross-sections through six different woods. Hexagons are fibres with fibre wall in brown and fibre lumen in bright yellow. Green is parenchyma (axial + ray). Vessel fraction was relatively small, and did not show large variation across species, so for simplicity was omitted in this diagram. Wood density increases towards the top of the diagram. Total fibre fraction (brown wall + yellow lumen) and total parenchyma fraction (green, includes axial + ray) covary negatively with each other and approximately orthogonally to wood density.
Fig 5.
Relationships between axial parenchyma fraction, ray fraction, conduits15μm fraction and vessel area (i.e. cross-sectional average area).
Green circles—tropical rainforest (warm and wet site); red squares—tropical woodland (warm and dry site); blue triangles—temperate forest (cool and wet site). * P < 0.05, ** P < 0.01, ns—not significant.
Fig 6.
Relationship between ray fraction and leaf area to sapwood area ratio.
Green circles—tropical rainforest (warm and wet site); red squares—tropical woodland (warm and dry site); blue triangles—temperate forest (cool and wet site). ** P < 0.01.
Fig 7.
Relationship between axial and ray parenchyma fractions and height.
Green circles—tropical rainforest (warm and wet site); red squares—tropical woodland (warm and dry site); blue triangles—temperate forest (cool and wet site). * P < 0.05, ** P < 0.01.
Fig 8.
Relationships between axial and ray parenchyma fractions, wallF+V fraction and modulus of elasticity.
Each symbol is an individual species. Symbol type represents site of collection: green circles—tropical rainforest (warm and wet site), red squares—tropical woodland (warm and dry site) and blue triangles—temperate forest (cool and wet site). * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.
Fig 9.
Relationship between ray parenchyma fraction and pith area (log-transformed).
Green circles—tropical rainforest (warm and wet site); red squares—tropical woodland (warm and dry site); blue triangles—temperate forest (cool and wet site). *** P < 0.001.