Ecology of Amazon Palms

Abstract In this chapter, I review some of the ecological studies of palms that have been carried out in the Amazon region. As will become obvious, considering the size of the region and the abundance of the family, we know very little about ecology of Amazon palms. Nevertheless, these studies are of great interest to systematists because they provide explanations for morphologic and geographic patterns. Francis Kahn and co-workers have carried out extensive studies on the relationship of palms to their physical environment in the Amazon region (summarized in Kahn and de Granville, 1992). They noted that the palm flora of the western part of the Amazon was richer in species than that of the central or eastern regions, and that diversity of palms was greater in terra firmeforests than in inundated areas. Furthermore, most of the increase in diversity in the west was due to terra firmespecies; in general, inundated forests have a rather homogeneous palm flora. Overall, they found that most species of palms were small, understory plants; the number of tall, arborescent palms was very low. The reasons for this community structure were to be found in forest architecture and dynamics. Development of arborescent palms depended on high light intensity, and these conditions were found in inundated forests. Here such common arborescent palms as Mauritia lexuosaand Oenocarpus batauaoccurred. These palms were highly specialized for growth in waterlogged soils.