Tropical forests are being deforested at an alarming rate, but also have the potential to regrow naturally on abandoned lands. A study published this week in Science shows that regrowing tropical forests recover surprisingly fast, and after 20 years can attain nearly 80% of the soil fertility, soil carbon storage, structure and tree diversity of old-growth forests. The study concludes that natural regeneration is a low-cost, nature-based solution for climate change mitigation, biodiversity conservation and ecosystem restoration.
"These are forests that have been logged in the past and have been left to return to forests," said Caroline Farrior, an assistant professor in the Department of Integrative Biology at The University of Texas at Austin who helped design the research and analyze data. "This recovery process is likely a major part of the current land carbon sink that is keeping carbon dioxide from increasing as quickly in the atmosphere."
The international team of tropical ecologists analyzed how 12 forest attributes recover during the natural process of forest regeneration, and how their recovery is interrelated using 77 landscapes and more than 2,200 forest plots across tropical North, Central and South America, and West Africa.
Secondary forests are those that regrow naturally after nearly complete removal of forest cover for human use such as farming or cattle ranching. Currently over half of the world's tropical forests are not old-growth, but naturally regenerating forests of which a large part is secondary forest. In tropical Latin America, secondary forests cover as much as 28% of the land area.
"These regrowing forests cover vast areas, and can contribute to local and global targets for ecosystem restoration," said Lourens Poorter, a professor of functional ecology at Wageningen University, the Netherlands and lead author of the study. "They provide global benefits for climate change mitigation and adaptation and biodiversity conservation, and many other services for local people, such as water, fuel, wood and non-timber forest products."
This research is a product of the 2ndFOR collaborative research network on secondary forests. It involves over 100 researchers from 18 different countries. The network focuses on the ecology, dynamics and biodiversity of secondary forests, and the ecosystem services they provide in human-modified tropical landscapes.
"Given the local and global importance of secondary forests and their rapid recovery after 20 years, we encourage adoption of (assisted) natural regeneration as a low-cost, nature-based solution to meet the objectives of the United Nations' Sustainable Development Goals, the UN Decade of Ecosystem Restoration, UN Framework Convention on Climate Change and the Convention on Biological Diversity," said Bruno Hérault, a tropical forest scientist at The French Agricultural Research Centre for International Development (CIRAD), Ivory Coast and last author of the study.
This research was supported in part by the European Research Council Advanced Grant PANTROP and by Deutsche Forschungsgemeinschaft.
Adapted from a release by Wageningen University.
Comments