MID AND LATE HOLOCENE VEGETATION CHANGE IN QUINTANA ROO, MEXICO

Different pollen records of Mid to Late Holocene sediment cores from the Mexican Caribbean coast (Quintana Roo) show the development and changes of mangrove and tropical forest ecosystems. In southern Quintana Roo moist conditions prevailed and high forest was present around 5000 14C yr BP. Around 4200 14C yr BP the high forest was replaced by mangrove vegetation, probably due to permanent flooding of the Rio Hondo river. In northern Quintana Roo a palynological analysis revealed humid climatic conditions for the period approximately 2500-1500 14C yr BP, and mangrove Rhizophora mangle dominated with a good representation of elements from the nearby semi-evergreen tropical forest. During the period approximately 1500-1200 14C yr BP the mangrove Conocarpus erecta dominated. R. mangle almost disappeared and other taxa appeared, suggesting drier climatic conditions and generally more open vegetation. This dry period coincided with the period of the Maya cultural decline. The following period (approximately 1200-1000 14C yr BP) was characterized by the recovery of R. mangle, indicating more humid conditions than in the preceding pollen zone. Approximately 1000 14C yr BP till present drier periods occur with C. erecta; this marks the transition to present day conditions.