Hyperspectral remote sensing of canopy chemistry, physiology, and biodiversity in tropical rainforests

Whether one is observing from the ground or from above the canopy, humid tropical forests are among the most complex of biological constructs found in nature. Species diversity is usually high, and the vertical layering of canopies is often pronounced. Tree mortality and regrowth occur throughout a rainforest, resulting in a mosaic of canopy gaps and tree ages, with concomitant variability of local species dominance and canopy structural properties [1]. Overlain on these natural sources of variation are community-and ecosystem-level changes that come at the hand of the human enterprise. We clear-cut, selectively log, occupy, and/or abandon thousands of square kilometers of tropical forests each year [2,3], causing regional variations of taxonomic composition and canopy structure. Together, these natural and anthropogenic sources of variation result in a complexity of ecosystem form and function that challenges ground-based studies.