Humans have been altering tropical forests for at least 45,000 years

The first review of the global impact of humans on tropical forests in the ancient past shows that humans have been altering these environments for at least 45,000 years. This counters the view that tropical forests were pristine natural environments prior to modern agriculture and industrialization. The study, published today in Nature Plants, found that humans have in fact been having a dramatic impact on such forest ecologies for tens of thousands of years, through techniques ranging from controlled burning of sections of forest to plant and animal management to clear-cutting. Although previous studies had looked at human impacts on specific tropical forest locations and ecosystems, this is the first to synthesize data from all over the world.

The paper, by scientists from the Max Planck Institute for the Science of Human History, Liverpool John Moores University, University College London, and École française d'Extrême-Orient, covered three distinct phases of human impact on tropical forests, roughly correlating to hunting and gathering activities, small-scale agricultural activities, and large-scale urban settlements.1

The deep human prehistory of global tropical forests and its relevance for modern conservation

Patrick Roberts, Chris Hunt, Manuel Arroyo-Kalin, Damian Evans and Nicole Boivin

Nature Plants 3, Article number: 17093 (2017)

doi: 10.1038/nplants.2017.93

Significant human impacts on tropical forests have been considered the preserve of recent societies, linked to large-scale deforestation, extensive and intensive agriculture, resource mining, livestock grazing and urban settlement. Cumulative archaeological evidence now demonstrates, however, that Homo sapiens has actively manipulated tropical forest ecologies for at least 45,000 years. It is clear that these millennia of impacts need to be taken into account when studying and conserving tropical forest ecosystems today. Nevertheless, archaeology has so far provided only limited practical insight into contemporary human–tropical forest interactions. Here, we review significant archaeological evidence for the impacts of past hunter-gatherers, agriculturalists and urban settlements on global tropical forests. We compare the challenges faced, as well as the solutions adopted, by these groups with those confronting present-day societies, which also rely on tropical forests for a variety of ecosystem services. We emphasize archaeology's importance not only in promoting natural and cultural heritage in tropical forests, but also in taking an active role to inform modern conservation and policy-making.