The discoveries could boost indigenous populations’ claims to ancestral lands long thought to be untouched by human activity
- by Josie Garthwaite
"A tropical forest writes much of its history at large scale, producing trees as tall as skyscrapers and flowers the size of carry-on luggage. But by zooming in, scientists are uncovering chapters in forest history that were influenced by human activity far earlier than anyone thought.A new study of pollen samples extracted from tropical forests in southeast Asia suggests humans have shaped these landscapes for thousands of years. Although scientists previously believed the forests were virtually untouched by people, researchers are now pointing to signs of imported seeds, plants cultivated for food, and land clearing as early as 11,000 years ago—around the end of the last Ice Age. The study, to be published in the peer-reviewed Journal of Archaeological Science comes from researchers led by paleoecologist Chris Hunt, of Queen’s University, Belfast, who analyzed existing data and examined samples from Borneo, Sumatra, Java, Thailand and Vietnam.
Pollen offers an important key for unlocking the history of human activity in a region where dense tropical forests make traditional excavations slow, arduous work, and thick canopies hinder aerial surveys. Reliance on building materials that perish with the centuries (rather than stone or ceramic) can make it difficult to recognize signs of long-gone inhabitants. Pollen, however, can survive for thousands of years in the right conditions and paint a picture of vegetation over time.
In the Kelabit Highlands of Borneo, for example, pollen samples dated to about 6,500 years ago contain abundant charcoal evidence of fire. That alone doesn’t reveal a human hand. But scientists know that specific weeds and trees that flourish in charred ground would typically emerge in the wake of naturally occurring or accidental blazes. What Hunt’s team found instead was evidence of fruit trees. “This indicates that the people who inhabited the land intentionally cleared it of forest vegetation and planted sources of food in its place,” Hunt explained in a statement about the study” (read more).