Despite high biodiversity and productivity, many tropical forests are found on highly weathered, low nutrient soils, with especially low phosphorus and cations. Large-scale nutrient addition experiments are direct and powerful approaches to understand nutrient limitations in tropical forests. However, limited experiments, differences in methodology, and parameters measured make global comparisons across this diverse biome difficult. We propose the establishment of a network of large-scale nutrient additions across tropical forests to develop a new paradigm soil nutrient limitation on ecosystem processes, such as carbon and nutrient cycling, plant productivity, and better predict resilience to global changes.
