Natural and cultural landscape evolution during the Late Holocene in North Central Guatemalan Lowlands and Highlands

Paleoecology has been only in recent decades applied to Mesoamerica; this thesis provides new records of paleoenvironmental changes in Guatemala. Paleoecological reconstructions are developed based mainly on pollen in the Lachua lowlands and Purulha highlands of the Las Verapaces Region. For the first time, quantitative vegetation and climate analyses are developed, and plant indicator taxa from vegetation belts are identified. Changes in vegetation are explained partially by elevation and climatic parameters, topography, drainage divides, and biogeography. Pollen rain and indicator plant taxa from vegetation belts were linked through a first modern pollen rain analysis based on bryophyte polsters and surface sediments. The latter contain fewer forest-interior plant taxa in both locations, and in the highlands, they contain higher local pollen content than in the lowlands. These calibrations aided vegetation reconstructions based on fossil pollen in sediment records from the Lachua and Purulha regions.;Reconstructions for the last ∼2000 years before present (BP) were developed based on fossil pollen from cores P-4 on a floodplain in Purulha, and L-3, a wetland in Lachua. Core P-4 suggests that Mayan populations developed a system of agricultural terraces in a former paleolake-swamp environment, which was abandoned at the time of the Spanish Conquest (∼400 BP). Core L-3 indicates the abandonment of Mayan "Forest Gardens" at the time of the early Postclassic. These gardens likely prevailed during the Classic period (∼300-1100 yrs BP) at the outskirts of the ancient city of Salinas de los Nueve Cerros. Following abandonment, forest recovery took place for about 800 yrs. Cultural factors are found to be more important in determining vegetation dynamics in this region, since no clear evidence of climate forcing was found. The P-4 and L-3 cores provide likely evidence that Mayan populations were, contrary to other evidence, innovative landscape managers. Scenarios in the Las Verapaces Region have been drastically modified in recent times (e.g. after the European Conquest), as suggested by pollen evidence in the top of both P-4 and L-3 cores, possibly due mostly to modern large scale natural resources exploitation, which represent environmental threats greater than any seen in the last ca. 2000 years.