MISSOULA – Plants take in and store carbon dioxide as they grow. As the amount of CO2 in the atmosphere increases, leading to rising temperatures and other climatic changes, researchers want to know if plant growth can keep pace with and take up more of this new CO2.
To grow faster, plants also need nutrients such as nitrogen and phosphorous in balance with the amount of new CO2. New research led by Cory Cleveland, a University of Montana professor of terrestrial biogeochemistry, examines where plants might be expected to grow more based on access to nutrients.
The study found that new sources of nitrogen are most available for plants in tropical rain forests but that phosphorus availability is low across the globe. Cleveland and his co-authors used satellite data to track plant production and the corresponding balance of carbon, nitrogen and phosphorous.
“Our global, satellite-based calculation allowed us to examine patterns of nutrient demand and cycling over a large scale,” Cleveland said. “This helped us pinpoint tropical forest ecosystems as those with the ability to increase plant productivity in response to other changes in the environment, at least from a nutrient cycling perspective. We also saw that forests outside the tropics have much more limited ability to grow more due to low inputs of new nitrogen and phosphorous relative to plant demands.”
Cleveland’s coauthors are from the University of California-Davis, the Southwest Biological Science Center of the U.S. Geological Survey, Colorado State University and the Agricultural Research Station of the U.S. Department of Agriculture.
The paper, “Patterns of New Versus Recycled Primary Production in the Terrestrial Biosphere,” came out in Proceedings of the National Academy of Sciences on July 15 .