A new study, published this week in Proceedings of the National Academy of Sciences, reveals that nitrogen-fixing trees play an underrecognized role in recovering tropical forests by enriching nutrient-poor soils with scarce elements such as phosphorus and molybdenum.
Coauthor Sarah Batterman, a tropical forest ecologist at Cary Institute of Ecosystem Studies, explains, “We’ve long known that nitrogen-fixing trees work with soil microbes to make atmospheric nitrogen available to plants. Our study found that nitrogen fixers also play a vital role in unlocking other nutrients by weathering rocks beneath their roots. These nutrients include things like phosphorus, which is very limited in tropical forest soils and important to plant growth.”
In this study, the team compared the soils of nitrogen-fixing and non-fixing trees across young recovering tropical forest plots that are part of the Agua Salud Secondary Forest Dynamics Network in the Panama Canal Area. They measured soil pH and mineral weathering – a process that releases nutrients trapped in rocks. They also assessed the composition of the soil microbial community.
Read more at Cary Institute of Ecosystem Studies
Image: Tropical forests in Panama are threatened due to agriculture, mining, development, and climate change. Reforestation is an important strategy to protect the tropical carbon sink. Nitrogen-fixing trees are known to be especially effective at helping regenerating forests grow quicker and store more carbon. (Credit: Sarah Batterman)