Abstract:
The past vegetation and climate dynamics of Southern Ecuador are still not well known, despite this region belonging to the worldwide hotspots of biodiversity (Mutke and Barthlott, 2005) with influences from Amazonia, the Andean Highlands and the Pacific Coast. In addition to that, a rich cultural heritage including the Inca civilization as well as many pre and post-incaic cultures belong to the history of this Andean country. To know more about past vegetation changes in response to climate and human impact, we present a Postglacial pollen and charcoal sequence from the mire Laguna Vendada (3640 m a.s.l.), covering approximately the last 18,200 calibrated years BP. Deglaciation at the site started before 18,000 cal. yr BP and vegetation was very sparse during the Lateglacial. Before the onset of the Holocene, vegetation was dominated by cold and moist adapted species during the Younger Dryas cooling. Below the site, forests expanded at the beginning of the Holocene and reached largest expansions during the Mid-Holocene (between ca. 7500 and 2000 cal. yr BP). Forests probably established around the site between 7500 6000 cal. yr BP. Human impact presumably started very early around Laguna Vendada, evident by a high fire frequencies and large abundances of dung spores since ca. 8000 cal. yr BP. This early and persistent impact on vegetation might explain the reduction to isolated patches of today’s treeline Polylepis forests.
