This study arose out ofthe old question of what actually determines vegetation structure and distributions. Is climate the overriding control, as one would suppose from reading the more geographically oriented literature? Or is climate only incidental, as suggested by more site and/ or taxon-oriented writers? The question might be phrased more realistically: How much does climate control vegetation processes, structures, and distributions? It seemed to me, as an ambitious doctoral student, that one way to attempt an answer might be to try to predict world vegetation from climate alone and...