Dicotyledonous wood anatomical characters as predictors of climate

The relationships among wood anatomical characters and climate are examined for 50 wood anatomical features in floras from 37 regions in North America, South America, Africa and Malaysia. Correlations, simple regressions and multiple regressions, were used to develop models for the prediction of climate from wood anatomy. The climate variables considered were: mean annual temperature, mean annual range in temperature, cold month mean temperature, mean annual precipitation, precipitation of the driest month and length of the dry season. Good correlations were found with temperature; poorer correlations with precipitation. The climate variables, especially the temperature-related ones, were best predicted by two or more wood anatomical characters considered together. Characters that we selected to calculate climate variables are: vessels with multiple perforations; spiral thickenings present in the vessels; vessel mean tangential diameter less than 100 μm; fibers septate; rays commonly more than 10 cells wide; rays heterocellular with four or more rows of upright cells; rays storied; axial parenchyma absent or rare; marginal parenchyma present; and wood ring-porous. Models were validated on seven temperate and six tropical sites. Based on these results, a method for determining paleoclimate from fossil wood assemblages is suggested.