Ecosystem restoration is a great opportunity for tropical forests, but for corals we need to advance the science of restoration before it’s too late
By Paula Drummond
Ecosystem restoration is essential for restoring ecosystem services and biodiversity in terrestrial and marine environments. In tropical forests, natural regeneration is an effective and economical solution for restoring large degraded areas, helping to sequester carbon and support wildlife. In marine environments, however, the restoration of coral reefs remains a challenge, particularly due to ocean warming. Corals play a role in protecting coastlines, supporting fisheries and providing shelter for many species. Restoring coral reefs requires multiple actions, including coastal and marine zone management, including pollution control and exotic species control.
Whether at sea or on land, ecological restoration is most effective when science, policy and community engagement are combined to ensure long-term resilience and sustainability.
The potential of global forest regeneration
Natural regeneration of tropical forests offers a unique opportunity to restore native biodiversity, forest functions and ecosystem services, says Robin Chazdon of the University of Connecticut. Long-term studies show that forests have their own recovery mechanisms that have accumulated over millions of years. However, the trajectory of forest succession can vary widely depending on factors such as previous land use, landscape conditions, and the characteristics of the species involved.
Forecast models based on 2020 data suggest that 215 million hectares of forest could regenerate globally by 2030. Brazil and Indonesia account for a third of this potential. In addition to being cost-effective, natural regeneration can provide significant economic benefits, such as storing 23.4 Gt of CO₂ over 30 years. In Brazil, where the potential for natural regeneration is the greatest in the world, this approach can be expanded using assisted regeneration methods, which would allow an additional 18.8 million hectares to be restored by 2035. This strategy reduces implementation costs by up to 77% compared to direct tree planting. To unlock this potential, however, it is essential to understand how different taxa and species, especially native and endangered ones, recover over time, and to map areas with greater viability for regeneration.
Coral reefs under threat
Coral reefs function as “underwater forests,” harboring rich biodiversity and playing a critical role in marine ecosystems. “Corals are threatened by overfishing, pollution and climate change, especially ocean warming and heat waves, which cause corals to bleach and die,” explains Guilherme Longo of the Federal University of Rio Grande do Norte. In Brazil, the composition of coral reefs along the coast varies greatly from north to south, with corals in the northeast being the most vulnerable to climate change.
Most of the global efforts are concentrated in the Pacific and Caribbean, focusing mainly on branching corals, which do not occur off the Brazilian coast. In addition, the growth of these organisms is slow, and experiments tend to involve only a few species. Cost is also an obstacle: restoring just 10,000 square meters can cost up to US$4 million.
Even with this investment, there are uncontrollable factors, such as ocean heat waves, that can jeopardize the entire effort.
“Coral restoration needs a solid scientific foundation. Without research, restoration efforts run the risk of being illusory, with no real long-term impact,” warns Longo. “In addition, we need to integrate science, society and public policy to protect reefs and the ecosystem services they provide,” he concludes.
Engagement as a strategy
Letícia Couto-Garcia of the Federal University of Mato Grosso do Sul (UFMS) emphasizes the importance of stakeholder engagement in ecological restoration efforts, with a particular focus on Brazil. She highlights the challenges to achieving restoration goals, such as conflicting interests and lack of communication between scientists, politicians, local communities and indigenous groups, and advocates a collaborative approach that integrates all these actors.
A key aspect that the researcher highlights is the appreciation of traditional knowledge, emphasizing the need for scientists to learn from indigenous communities in order to enrich restoration practices.
A concrete example comes from indigenous fire management in regions such as the Brazilian savannas. In the Kadiwéu indigenous territory, brigades formed by indigenous people and supported by the government use controlled techniques to prevent and fight fires. A study analyzing 18 years of data shows that these practices not only reduce the frequency and intensity of fires, but also mitigate climate impacts in burned areas, demonstrating the effectiveness of this management in preserving the environment. Couto-Garcia also highlights the need to integrate this traditional knowledge into public policies in order to improve environmental management strategies. Finally, she highlights the fundamental role of women in these efforts, emphasizing the importance of gender equality in ecological restoration.
The Regenera project also reports on the experience of co-producing knowledge in immersive workshops with decision-makers as a key decision to integrate science into public policy. The results are presented in a Policy Brief, technical notes and a glossary on natural regeneration, with the aim of placing this restoration strategy within the scope of public policy for the Amazon. “So far, we have been able to provide information on how and where natural regeneration can serve as a strategy for ecosystem restoration. We haven’t seen the indicators widely applied yet, and we know we can improve them. But it is better to have foggy glasses than no glasses at all,” says Catarina Jakovac.
Through social media, Guilherme Longo has launched a citizen science initiative. #DeOlhonosCorais has existed on Instagram since 2018, inviting divers in particular to post photos of corals and their location using the project’s hashtag. “At first it was a difficult experience, another language, but we learned how the rules [of Instagram] work and played the game. We had impressive results.” It was through a citizen scientist’s photo that the state of Rio Grande do Norte received the first notification of the sun coral, an invasive species that threatens coral biodiversity off the Brazilian coast. “With this information, the Rio Grande do Norte State Environmental Agency [IDEMA] launched a program to control the invasive species off the coast of Rio Grande do Norte,” adds Guilherme Longo.
About the São Paulo School of Advanced Science “Co-designing Biodiversity Assessments”
Organized by Unicamp’s Graduate Program in Ecology, with support from Fapesp, the São Paulo School of Advanced Science “Co-creating Biodiversity Assessments” brought together 57 participants from 22 countries on four continents, including graduate students, early career researchers, environmental managers and technicians. The participants spent 14 days in São Pedro (SP) discussing ways to integrate academic and practical knowledge on biodiversity to support decision-making.