ABSTRACT
The forests of the tropics and subtropics represent a diversity of habitats (e.g., rainforests, mangroves, and wooded savannas) that vary both spatially and temporally. Spatial variables include species diversity, structural attributes (e.g., height, cover, stem density, and vertical stratification), and biomass and are influenced by factors such as soils, geology, climate, topography, and the past biogeographic distributions of species. Temporal variables relate to seasonal phenology (e.g., period of leaf cover ranging from deciduous to evergreen) and growth stage and are influenced primarily by climate (e.g., drought) and hydrology (e.g., flood or tidal inundation). These forests are also changing over time as a consequence of disturbance (e.g., fires, logging) or enhancement of growth (e.g., woody thickening [1]). Such changes are attributable to both natural and direct (e.g., deforestation) or indirect (e.g., climate change) anthropogenic causes. A large proportion of forests are also secondary [2] and exist at varying stages of degradation or regeneration [3,4].
