XVI International Botanical Congess

Forests in equatorial western Amazonia have the highest recorded levels of tree alpha-diversity in the world. This makes the region at once a high priority for conservation and research and a difficult environment in which to research forest composition. There is considerable variation in tree species composition between localities, but the factors causing this variation are poorly understood because floristic studies are hampered by the exceptional alpha-diversity. We report results from over 40 samples of primary forest, representing a floristic research effort spanning 15 years. Samples were located to represent major edaphic formations, with replication where possible. The association between forest floristic and spectral properties is evaluated using Landsat-TM images, to examine the potential for using satellite images to predict composition. The samples are also used to explore contrasting hypotheses of community assembly. In particular, the potential contributions of edaphic specialization vs. random species assembly are evaluated.