New research reveals that sufficient nitrogen in soil allows tropical forests to recover twice as fast after deforestation. Scientists tracked regrowth in Central America over decades, finding nitrogen key to faster tree return and greater carbon capture. The findings suggest natural strategies for enhancing reforestation without fertilizers.
Researchers from the University of Leeds have conducted the largest and longest experiment on nutrient impacts in tropical forest recovery. They monitored 76 plots across Central America, some cleared for logging or agriculture, for up to 20 years. Plots received varied treatments: nitrogen fertilizer, phosphorus, both, or none.
Results, published on January 13, 2026, in Nature Communications, show that adequate nitrogen doubled regrowth rates in the first decade compared to nitrogen-poor sites. Phosphorus alone had no similar effect. Collaborators included institutions like the Smithsonian Tropical Research Institute, Yale University, and Princeton University.
Lead author Wenguang Tang, who completed his PhD at Leeds, stated: "Our study is exciting because it suggests there are ways we can boost the capture and storage of greenhouse gases through reforestation by managing the nutrients available to trees."
The team advises against widespread fertilizer use due to risks like nitrous oxide emissions, a potent greenhouse gas. Instead, they recommend planting nitrogen-fixing legumes or restoring forests in nitrogen-rich areas influenced by pollution.
Tropical forests serve as vital carbon sinks, sequestering atmospheric carbon. The study estimates nitrogen limitations prevent storage of 0.69 billion tonnes of CO2 annually worldwide—equivalent to two years of UK emissions.
These insights arrive after COP 30 in Brazil, where the Tropical Forest Forever Facility was launched to aid forest protection and restoration. Principal investigator Dr. Sarah Batterman, an associate professor at Leeds' School of Geography, noted: "Our experimental findings have implications for how we understand and manage tropical forests for natural climate solutions. Avoiding deforestation of mature tropical forests should always be prioritized, but our findings about nutrient impacts on carbon sequestration is important as policymakers evaluate where and how to restore forests to maximize carbon sequestration."
