The Amazon region, the Earth’s most important ecosystem, is home to more than 400 Indigenous groups that use thousands of rainforest plant species. They pass on their knowledge of the flora primarily through oral tradition, usually from parents or other family members to their children. This creates a “living library of knowledge” about how to use the native plants. Until now, little was known about how this treasure trove of knowledge is affected by the combined effects of climate change and language loss. A new study by the University of Zurich (UZH) now provides the first reliable scientific data on the impact of global change on the biocultural heritage of the Amazon region.
To investigate the value of the Amazon region’s biocultural heritage, the research group led by UZH professor of Tropical Plant Diversity and Ethnobotany Rodrigo Cámara Leret began by compiling a database documenting all reports on plant use in Amazonian countries and territories (Brazil, Peru, Colombia, Bolivia, Ecuador, Venezuela, Guyana, Suriname and French Guiana). The researchers collaborated with Patrick Roehrdanz, Director of Climate Change and Biodiversity at Conservation International’s Moore Center for Science in the United States. Commenting on the significance of the database, study leader Rodrigo Cámara Leret says: “For the first time, we synthesized information dispersed across 700 references spanning more than 500 years, revealing that Amazonian peoples use at least one-third of the region’s known plant species.” In absolute terms, this amounts to 5,796 plant species.
Indigenous peoples use 5,796 plant species
Although the database represents a major step forward, Cámara Leret believes that further ethnobotanical fieldwork will lead to important new discoveries. “For example, our participatory work with the Indigenous Cacua people led to the description of a new canopy palm species previously unknown to science, despite being locally abundant and long recognized by the Cacua as a key source of food security,” says the researcher.
Plants play a key role in Indigenous societies in many ways: as food, including legumes, peach palms, patauá oil and much more, in cultural practices such as communal customs or hunting, in construction and as medicine. “Tobacco, for example, is a plant that is used in many ways in everyday life,” explains Cámara Leret. Indigenous people not only chew the leaves of the tobacco plant as a stimulant but also burn them before entering the rainforest to signal the arrival of humans. The distinctive smell is said to appease the forest spirits and give dangerous animals, such as snakes, time to retreat. “Such everyday rituals reflect a respect for nature and an awareness of humanity’s dependence on the rainforest,” says co-author Jordi Bascompte, professor of Ecology at UZH. Moreover, such rituals define the cultural identity of Indigenous groups, just as French or Italian cuisine helps define the identity of those countries.
One-third fewer plants used in future
In a second step, the researchers fed the collected plant-use data into 8,429 species distribution models and simulated the future of these plants based on three climate scenarios from the Intergovernmental Panel on Climate Change (IPCC). However, many of the plant species currently in use are already rare and found only in a few areas, where they are increasingly being displaced by hyperdominant species.
The researchers have now shown that between 2060 and 2080, the ranges of plant species used by humans will shrink more significantly due to climate change than those of plant species not used by humans. Specifically, Indigenous cultures may lose an average of 28% to 34% of the plant species they use and 18% to 23% of the associated ecosystem services as a result of climate change.
Biocultural heritage to decline by 26 percent
By focusing on plants used by humans, the researchers were able to combine the effects of species loss with language extinction in the Amazon. When a plant species goes extinct, its Indigenous name, uses and benefits are lost as well, along with knowledge of its role in the rainforest ecosystem. As a result, the valuable body of knowledge about the world’s richest flora, which also helps shape cultural identity, is gradually disappearing.
The study quantifies for the first time the extent to which the biocultural heritage of the Amazon region is expected to diminish as a result of species and language extinction from 2060 to 2080: by 26 percent. “It turns out that the plants that Indigenous communities rely on could be decimated more severely than previously thought,” says Cámara Leret, adding: “But our results also suggest that the climate tipping point for Amazonia will not only impact biological diversity but also interact with language threat and cascade across the unique cultural heritage of the biome.”
Guide to biocultural restoration
The study’s findings, together with the publicly available dataset, may serve to guide biocultural restoration in the Amazon region, according to Cámara Leret. “We want our results to help stop, or even reverse, growing global change impacts on ecosystems and cultural traditions.” It is important to continue documenting knowledge about Amazonian flora in writing, in partnership with local Indigenous communities, while also preserving the tradition of oral transmission. Patrick Roehrdanz confirms: “Effective conservation will depend on recognizing Indigenous knowledge systems as fundamental to effective environmental stewardship. The study will help identify the locations where preserving culture and nature in tandem can have real impact for species that are currently under threat.” As Bascompte adds: “Recognizing this intimate dependence between the ecological and cultural heritages is key into assessing nature's contributions to people.”
Literature
Rodrigo Cámara Leret et al. “The forest of knowledge under global change.” Nature , 08 Jul 2026; DOI: 10.1038/s41586-026-10741-y
Contact
Prof. Dr. Rodrigo Cámara Leret
Department of Systematic and Evolutionary Botany
University of Zurich
Phone +41 44 634 84 11
E-mail rodrigo.camaraleret@uzh.ch
More information
Rodrigo Cámara Leret, Professor at the Department of Systematic and Evolutionary Botany, UZH
https://www.systbot.uzh.ch/de/research/camaraleret-group/rodrigo-camara-leret.html
Jordi Bascompte, Professor at the Department of Evolutionary Biology and Environmental Studies, UZH
https://www.ieu.uzh.ch/en/staff/member/bascompte_jordi.html
Patrick Roehrdanz, Director of Climate Change and Biodiversity at Conservation International, Arlington, US
https://www.conservation.org/profiles/patrick-roehrdanz
Conservation International, US
https://www.conservation.org/home
Nature
Data/statistical analysis
Not applicable
The forest of knowledge under global change
8-Jul-2026