Climate change threatens the future use of native tree species in Brazilian agroforestry systems

In the tropical regions of the world, where the air is thick with humidity and the canopy is a dense tapestry of green, farmers and conservationists are turning to a powerful tool to heal the land: agroforestry. This is not a new invention, but rather a return to an ancient practice of mixing trees with crops. Instead of clearing a forest to plant a single crop like corn or soy, agroforestry weaves together food production and forest restoration. The trees provide shade, protect the soil from erosion, and store vast amounts of carbon, while the crops feed families and generate income. In Brazil, where the Amazon and the Atlantic Forest are under constant pressure from agriculture, these systems offer a way to keep the land productive without destroying the biodiversity that makes the region so unique. However, the trees chosen for these systems are living things that depend on specific weather patterns to survive. They need just the right amount of rain and a specific range of temperatures to thrive. As the global climate shifts, bringing hotter temperatures and changing rainfall patterns, the question arises: will the trees we rely on today still be able to grow in the places we plant them tomorrow?

A team of researchers set out to answer this question by looking at twenty-four native tree species that are highly valued for their potential in Brazilian agroforestry. These trees, ranging from the mighty Brazil nut to the beloved cacao, are currently considered the backbone of sustainable farming in the Amazon and the Atlantic Forest. The scientists used computer models to map out where these trees can grow today based on current weather data. They then projected forward into the future, simulating how the climate might change under different scenarios of greenhouse gas emissions. The goal was to see if the areas where these trees currently flourish would remain suitable, or if the changing climate would push them out of their traditional homes. The researchers also considered a critical factor: the ability of these trees to move. In nature, seeds travel on the wind or are carried by animals to new places where the climate might be better. The study tested two possibilities: one where the trees could not move at all, and another where they could spread freely to any new area that became suitable.

The results of these simulations paint a sobering picture for the future of native tree farming in Brazil. When the researchers assumed the trees could not move to new locations, every single one of the twenty-four species faced a loss of suitable habitat. Some species lost only a small fraction of their range, but others faced a catastrophic decline. For instance, the Schizolobium parahyba, a fast-growing tree often used in restoration, was projected to lose nearly all of its suitable area in some future scenarios. On average, the suitable land for these trees shrank by more than half in both the Amazon and the Atlantic Forest. Even when the researchers allowed for the possibility that the trees could spread to new areas, the outlook remained challenging. While some species managed to find new ground and expand their range, the overall area available for planting these native trees on lands that are legally available for restoration continued to shrink. The changing climate is effectively squeezing the space available for these species, making it harder to establish new agroforestry systems in the places where they are most needed today.

The study also revealed that the impact of climate change is not uniform across the landscape. Some regions are becoming less hospitable, while others remain stable or even become more suitable. The researchers identified specific areas that are likely to remain climatically stable, acting as safe havens for these trees in a warming world. In the Amazon, these stable zones are concentrated in the central parts of the region, while in the Atlantic Forest, they form a corridor along the coast stretching from the state of Bahia down to Santa Catarina. These areas are where the climate is expected to stay within the range that these trees can tolerate, making them priority locations for future planting and restoration efforts. Conversely, the edges of the forests, where different ecosystems meet, are showing the most dramatic shifts. These transitional zones, which have historically been the focus of agricultural expansion, are becoming increasingly uncertain places for long-term tree planting.

One of the most striking findings involves the cacao tree, a species that is central to the economy and culture of the Atlantic Forest. The simulations showed that while cacao might find new opportunities in parts of the Amazon, its traditional home in the Atlantic Forest is becoming increasingly restricted. The suitable land for cacao is shrinking and retreating to a few specific pockets of stability along the coast. This highlights a complex reality: a species that is currently considered perfect for a region may no longer be a good choice there in thirty or forty years. The trees that farmers plant today will be living for decades, and if the climate changes faster than the trees can adapt or move, those investments could fail. The study suggests that relying on current maps of where trees grow is no longer enough. To ensure the success of agroforestry in the future, planners must look ahead. They need to select species not just for how well they grow today, but for how well they will survive the weather of tomorrow.

The research does not suggest that agroforestry is doomed, but rather that it must evolve. The authors emphasize that the long-term success of these systems depends on integrating climate predictions into the very first steps of planning. By identifying which species are most vulnerable and which regions are likely to remain stable, landowners and policymakers can make smarter choices. They can focus their restoration efforts on the areas that will remain suitable for the long haul, rather than planting trees in places that may become too hot or too dry in the coming decades. This approach, often called climate-smart agroforestry, is about building resilience. It means accepting that the landscape of the future will look different from the landscape of the past and adapting strategies accordingly. The study serves as a clear warning that without these adjustments, the potential of native trees to support both the economy and the environment in Brazil could be severely limited by the changing climate. The path forward requires a shift in perspective, moving from planting for the present to planting for a future that is already taking shape.