Landscape effects of hunter-gatherer practices are reshaping the idea of ​​agriculture

Some of the wild plants growing across the Australian landscape may not be so wild, according to new research by Penn State scientists.

The researchers studied four wild Australian plants (three test species and a control group) and how the hunting and gathering practices of the Martu Aboriginal people affected where these undomesticated plants grew in the landscape. They found that the three species tested, particularly the wild tomato, depend on human activity for seed dispersal.

The results, published in Natural communicationschallenge the conventional notion of agriculture and suggest that humans have had an impact on the genetic diversity of plants long before the advent of agriculture.

“This research is one of the first to show that peoples who are not yet engaged in agriculture still have long-term effects on plant populations,” said Rebecca Bliege Bird, first author of the study. and professor of anthropology at Penn State. “In Australia we’re talking about 50,000 years of Aboriginal involvement with these plants.”

The Martu Aboriginal people have lived in Australia for thousands of years and have largely retained their hunter-gatherer lifestyle to the present day, eschewing the permanence of specific cultures for their nomadic customs, the researchers said. Many avoided contact with European settlers and their descendants until the 1960s, when the government expelled them from their ancestral lands before conducting ballistic missile tests. They began returning to their lands in the 1980s, according to researchers.

To see how Martu customs and practices affect the distribution of plants in the landscape, the researchers focused on three edible plants important for subsistence and cultural identity: raisin, bush tomato and grass. love, which the Martu winnow and transform into flour. The researchers also looked at the distribution of fanflower, which is not actively harvested.

Researchers accompanied Martu harvesters on foraging expeditions over a 10-year period and studied plants in active and archaeological dinner camps where Martu people processed and consumed these and other foods.

They also used satellite data and ecological studies to understand the landscape impacts of fires intentionally set by Martu hunters to hunt game. Then they entered the data, such as site type, nearest water permanence and fire frequency, into statistical models to see which variables most likely contributed to the presence or absence of the four plants in the landscape.

They found that all three edible plants, particularly bush tomato and sweetgrass, rely heavily on both seed dispersal and the use of landscape fire for their spread across the landscape. For example, Martu pickers can taste bush tomatoes while picking the fruits to ensure they are sweet, discarding the bitter seeds into the bush tomato field.

Or, after harvesting and transporting the fruit closer to the community, they can discard the seeds while processing the bulk fruit around a campfire, Bliege Bird said. Bushgrape persists only in landscapes where people actively burn landscape fires to hunt small animals.

“These results challenge all our ideas about agriculture,” said Douglas Bird, co-author of the study and professor of anthropology at Penn State. “Rather than viewing the difference between agricultural and hunter-gatherer societies as a matter of nature, we would do better to view it as a matter of degree: people influence plants long before they engage in what we consider it a matter of degree.

The findings have implications for global efforts to conserve plant and animal species and highlight the importance of indigenous participation in these efforts, according to the researchers.

“In Australia, the importance of an anthropogenic – or human-influenced – landscape for certain species was critical in the 20th century,” Bliege Bird said. “In addition to supporting the persistence of edible plants, many of Australia’s small native mammals, particularly those of the desert, were dependent on the anthropogenic fire mosaic. When native fire activity was suppressed, many of these small animals have disappeared locally or even on a continental scale.

“Recognizing Indigenous participation in landscapes and ecosystems not only helps us design better conservation policies, but also helps support Indigenous rights to access traditional lands and resources.

Other contributors to the research include Christopher Martine, Bucknell University; Chloe McGuire, Far West Anthropological Research Group; Leanne Greenwood, Dja Dja Wurrung Clans Aboriginal Society; Desmond Taylor, Martu Elder, KulyakartuAboriginal Corporation Tanisha Williams, University of Georgia; and Peter Veth, University of Western Australia.