El Instituto de Ecología, A.C., se complace en invitar al
“The few and the many: The development of lowland tropical rainforest and of angiosperm diversity”
Dr. Peter Stevens
Missouri Botanical Garden
University of Missouri, St. Louis
Miércoles 18 de marzo de 2015, 13:00 Hrs.
Auditorio UNIRA, INECOL, A.C.
This is a talk that raises more questions than answers, and I focus on two very different aspects that bear on the development of lowland tropical rainforest. First. The evolution of vascular cambia, dense venation and small stomata are some of the features of seed plants that have been driving biosphere evolution for millions of years. Here I emphasize the importance of smaller clades of seed plants like ectomycorrhizal plants, usually trees, that often dominate their communities, cover very large areas of the earth’s surface, and are involved in the mid- to longer term sequestration of large amounts of carbon; other important players in this regard are C4 plants, mangroves and seagrasses. Without these organisms, the world would look very different. Second. When thinking of floral diversity, images of humming-birds “adapted to” flowers with corollas of appropriate lengths spring to mind. Here I survey plant/animal relationships in several groups of generalist but paradoxically specialized pollinators like hummingbirds and orchid and bumble bees. This leads to thoughts about when lowland tropical rainforest with its diversity of biotic interactions developed. Although dating of both plants and animals is a very problematic area, suggestions are that the diversification of critical groups such as these pollinators, fruit-eating primates, arboreal ants, and the like is a post-Palaeocene phenomenon. Fossils suggest a rather different geography of biota then. Asking how and when close plant-animal relationships evolved means that the present may be an imperfect guide to the past.