Rosario Costa-Cabral and her brothers harvest hundreds of products from the rainforest: woods like pau mulato and pracuúba, oil for cosmetics from the pracaxi tree, palm fronds for thatch, and fruits like açaí, bananas, guava and cupuaçu. Twice a day, tides swell the delta’s lacework of rivers and streams, flooding the forest and creating a rich nursery for shrimp and dozens of species of fish that serve as an important source of food and income. Without the forest, they say, you lose the fish and shrimp.
But now the tides run higher than in years past. The spring floods that threaten delta communities last longer and cause more damage; and the dry spells in late fall are growing drier. The climate is changing.
A team of scientists, led by Miguel Pinedo-Vasquez of Columbia’s Earth Institute, has come to the delta to find out how Rosario and her fellow caboclos—the people of mixed bloodlines who live here—are adapting. The researchers want to understand how the climate is changing, and how they can help with better forecasting and strategies for adaptation.
What Rosario is doing in this far-off backwater of Brazil may offer important lessons: Where the land was once stripped for logging and cattle ranching, she cultivates a living by helping the rainforest to regrow. That not only benefits her. It can help fight climate change, preserving part of the vast Amazon rainforest that plays an important role in regulating rainfall and that helps absorb carbon dioxide, the principal heat-trapping gas that contributes to warming the planet.
Rosario also experiments with new crops, seeking by trial and error to discover what will grow best in her changing environment. The higher tides and floods make it impossible in many areas for the caboclos to grow field crops they have traditionally relied on—cassava, corn, tomatoes, beans and squash. For instance, at the base of her açaí trees, Rosario has started planting pineapple, native to the region.
She is learning, and teaching others, how to sustain the rainforest and its rich diversity of life for the future.
“If we’re going to look at sustainability, we have to start looking at these systems,” Pinedo-Vasquez said. It’s not enough to study the habitat of the rainforest alone, he said. “We don’t provide any measurements of ecological systems and interactions with people, the energy transfer. … We need to know how humans interact with the ecosystem and affect the ecosystem services.”
Pinedo-Vasquez leads a team of scientists from northern Brazil and Canada on this four-year project, titled “Socio-Cultural Adaptations of Caboclos in the Amazon Estuary of Brazil to Extreme Tidal Events.” Funding comes primarily from the International Development Research Centre, established by the government of Canada to help developing countries. Pinedo-Vasquez, a native of the Peruvian Amazon, teaches at Columbia, conducts research and directs international programs for the Earth Institute Center for Environmental Sustainability.
Katia Fernandez, from the International Research Institute for Climate and Society, a research center of the Earth Institute, will work on climate data and prediction models. Oriana Almeida is the head of the project in Brazil, and her husband, Sergio Rivero, is in charge of an economic survey; both are professors at the Federal University of Pará, in the city of Belém. Also participating in surveys, data collection and analysis are Nathan Vogt at the Amazonia Research Center of the National Institute for Space Research of Brazil; Fernando Rabelo, a forester and professor at the State University of Amapá; and Peter Deadman of Waterloo University in Canada.
The researchers are surveying local residents, collecting historical records on floods and tides, and gathering government records of the region’s economic output. They’ll set up monitoring stations along rivers to gather data about tide heights, water temperature, salinity and pH, and duration of the larger seasonal floods, called lançantes. The researchers will provide scientific instruments to 16 farm families in the north and south of the Amazon delta. The families will maintain logs tracking floods, currents, winds and sedimentation.
In the end, Pinedo-Vasquez and his team hope to have a picture of how the climate and the regional weather and water systems have changed, and how people are adapting. They want to create tools to predict climate on the regional scale—offering advance warning of possible high rainfall, floods and drier spells, information that can be used by the local people and the government to plan ahead, explore alternative strategies and better adapt to change.
“For adaptation, keeping a space is more important than keeping products. If you don’t have the forest, you don’t have products,” Pinedo-Vasquez said. “So, you have many products that the forest can give you. [For] each one, we need to … quantify what is the sustainable way of using these resources. Some resources, some tree species make take 200 years. It cannot be sustainable to have one or two trees in the forest. In 200 years’ rotation, it’s almost impossible to argue if you cut the trees to alter that, you are harvesting sustainably.”