The ecoclimatology of Danum, Sabah, in the context of the world's rainforest regions, with particular reference to dry periods and their impact

Climatic records for Danum for 1985-1998, elsewhere in Sabah since 1879, an d long monthly rainfall series from other rainforest locations are used to place the climate, and particularly the dry period climatology, of Danum in to a world rainforest context. The magnitude frequency and seasonality of d ry periods are shown to vary greatly within the world's rainforest zone. Th e climate of Danum, which is aseasonal but subject, as in 1997-1998, to occ asional drought, is intermediate between less drought-prone north-western B orneo and the more drought-prone east coast. Changes through time in drough t magnitude frequency in Sabah and rainforest locations elsewhere in South- East Asia and in the Neotropics are compared. The 1997-1998 ENSO-related dr ought event in Sabah is placed into a historical context. The effects of dr ought on tree growth and mortality in the tropics are assessed and a model relating intensity and frequency of drought disturbance to forest structure and composition is discussed.