A new study that reviewed how prehistoric people impacted tropical forests thousands of years ago could present ideas for more effective conservation strategies.
Among the findings, the study provides a glimpse of tropical agricultural that differs greatly from common farming practices today.
The review, recently published in the journal Nature Plants, found that humans have been managing forests around the world for 45,000 years, domesticating native plants and clearing forests on small scales to provide for communities of various sizes.
“Indigenous agricultural practices that fit within the ecological dynamics of that forest are far better than cutting down an entire forest and trying to impose something that was domesticated or developed in a totally different part of the world," said Patrick Roberts, the study's lead author and researcher at the Max Planck Institute for the Science of Human History.
The study identified some common features of prehistoric agricultural practices, which tended to fit into mobile hunter-gatherer lifestyles and were developed with an understanding of what works within an environment.
“Even if a group of people are clearing forest for one crop, they’ll be moving around and using lots of other resources at the same time. And when that area becomes less fertile, they move, burning it and leaving it for a few years before coming back,” Roberts said, also noting that this differs depending on the community.
Larger prehistoric communities, such as Amazon civilizations that reached populations of 100,000 people, would use dispersed agriculture by designing cities to have a central area and then a number of “satellites.”
Today, an estimated 80 percent of tropical deforestation can be attributed to agriculture, Jonas Cedergren, a forestry officer (harvesting) for the Food and Agriculture Organization of the United Nations, said. This trend is most prevalent in low-income countries.
Deforestation is associated with various detrimental environmental impacts, such as reducing biodiversity and potentially increasing carbon emissions. However, agriculture is sometimes the only livelihood for people in tropical countries, and it can be an important part of a country's economy.
Because of this, changing agricultural practices to reduce or eliminate their footprint on forests is essential to meet future demands for agricultural products while maintaining ecosystems, Cedergren said.
Additionally, the long history of people relying on and managing tropical forests also means that working to return forests to a condition untouched by people is unrealistic, Roberts said.
Instead, Roberts believes a better option is to aim for something sustainable for both humans and tropical environments, and a crucial part of this goal is listening to indigenous people and learning from their agricultural practices.
“[Forests] have been managed by humans in many places for millennia, and so what do you return it to?” Roberts said.
Learning about how forests have adapted to human disturbance throughout history could also encourage including local communities in conservation practices, Cedergren said, and can help explain long-term impacts of human disturbance in forests.
Urban planning methods similar to those used thousands of years ago are being implemented now.
“Town planners today in tropical regions are adopting the dispersed approach in cities rather than the dense vertical approach, so actually even today we’re now realizing that what they were doing in the past was the best way to support dense populations in a given region,” Roberts said.