Legume–microbiome interactions unlock mineral nutrients in regrowing tropical forests
Dimitar Z. Epihov, Kristin Saltonstall, Sarah A. Batterman, Lars O. Hedin, Jefferson S. Hall, Michiel van Breugel, Jonathan R. Leake, David J. Beerling
Abstract
Significance Symbiotic dinitrogen (N 2 )-fixing trees fulfill a critical function in tropical forests by bringing in new nitrogen, yet it remains unclear how they overcome constraints by highly weathered, nutrient-poor tropical soils. We advance forest biogeochemistry and microbial ecology with the discovery from field trials in Panama that fast-growing N 2 -fixing trees in tropical forests exhibit accelerated mineral weathering and distinctive soil metagenomes that improve their access to inorganic nutrients in nutrient-poor soils. Furthermore, we show that N 2 -fixing trees exert similar effects on non-N 2 –fixing trees nearby thus having previously overlooked community-wide effects on tropical forest nutrient cycling. These results offer insights into the role of N 2 -fixing trees and their associated microbiomes in safeguarding the function of tropical forests within the global biosphere.