In the tropics where there is little variation in climate, the trees do not produce rings. Rings may be present if there is a marked wet and dry season. Dendrochronologists can coordinate tree ring patterns to reconstruct climate histories. Characteristics of Wood Porosity refers to the vessel dispersion in a given year's growth. Grain describes the alignment of the xylem cells-straight, tipped, spiral, curled, etc.
Figure is determined by the number of rays, the porosity, the grain, and the alignment of rings.
The presence or absence of knots also contributes to the figure. Different woods have different densities, grains, and mechanical properties. 1 cubic cm in volume is used to measure density. Since the mass of 1 cc of water is 1 g at sea level, any wood with a density higher than 1 will sink, while any wood with a density below 1 will float. XRT X is the cross-section of the wood.