Abstract

One of the least understood aspects of paleoscience is the role of climate in controlling long-term changes in human population, and, in turn, how changes in population influence the strategies that individuals use to manage resources. Understanding the nexus between climate, human population and the management of resources is important in a world where climate change is accelerating; populations are growing; and biological diversity is in decline, stressing systems of resource management. We propose the creation of PEOPLE 2K, a research network to study trade-offs inherent to the climate-human populationinstitutional adaptation dynamic, and to describe threshold changes in social-ecological systems (SES) Palaeoecology can offer unique insights into legacy impacts on forest composition and biodiversity because it affords a long temporal perspective, and in most cases, pre-date complex societies, so they can provide an ecological baseline. Here we review four case studies from lowland Belize, Southern Brazil Highlands, Llanos de Moxos, Bolivia and the lowland savannas of Bolivia that demonstrate how palaeoecology attempts to address the question of legacy effects on ecosystems that experienced varied pre-historic land-use and climatic changes during the last c.3,000 years. The comparison of pollen and physical characteristics of sediment cores and archaeological data of the four cases of Pre-Columbian impact on ecosystem composition provides evidence of variable effect for legacies of past land use. The intensity and type of past management, combined with ecosystem type as well as climate, might be key in controlling and whether or not anthropogenic modifications create long-term changes to ecosystems composition and biodiversity. The complexity illustrated by these studies highlights the challenges ahead for palaeoecology in disentangling the natural and human determinants of composition and biodiversity in tropical ecosystems.