GLOBAL PATTERNS OF TREE SPECIES RICHNESS IN MOIST FORESTS - ANOTHER LOOK

After examining some perceived inconsistencies in the relationship bet ween species richness and energy, Latham and Ricklefs rejected the Ene rgy Diversity Theory in favour of historical explanations of the geogr aphical patterns of tree species richness. We have reexamined Latham a nd Ricklefs's data, both by itself and pooled with Currie and Paquin's data. We find that Latham and Ricklefs's data are, in fact, consisten t with the richness-energy hypothesis. Because of strong collinearity between annual evapotranspiration and region in their particular data sets, the data cannot be used to distinguish between the hypotheses th at contemporary climate, versus some other interregional difference, i s responsible for observed species richness patterns. Finally,, there is no particular reason to attribute differences among regions to hist orical factors rather than to contemporary ones.