Tropical forests may have many species, indeterminate ages, and a wide
range of growth habits and stem sizes and thus require special modeli
ng techniques. But technique contributes only part of model quality, a
nd much depends on the calibration data and access to the model. Whole
stand models have limited utility in these forests, as it is hard to
describe the forest adequately with few stand-level variables. Stand t
able projection and matrix models may be useful where summarized data
are available and computer resources are limited, but the many classes
required detract from the method. Tree list models offer greater flex
ibility, enable projections under a wide range of conditions, and prov
ide diverse information. All growth equations should ensure reliable p
redictions over all tree sizes, sites, and stand conditions. Mortality
may be modeled with logistic functions fitted to individual tree data
. Two-stage recruitment models are a practical way to predict regenera
tion where there are many species. Several existing models could be ca
librated for tropical rainforests if suitable data were available. Sus
tainable use of rainforests may depend on maintaining nutrient cycles
and ecosystem linkages, and new data and innovative models will be nec
essary to fully appraise these aspects.