Root Fungal Association Determines Soil Nutrient Acquisition Strategies of Plants

Feedbacks between plant nitrogen demand and rhizosphere priming depend on type of mycorrhizal association.

The Science

Plants and the fungus that grow on their roots have symbiotically evolved together and adapted unique strategies for acquiring nutrients from soil that is dependent on the species of fungus. This association can determine a wide variety of things from leaf litter decay rates to plant carbon allocation to wood, roots, and sugars provided to the root fungus in trade for nutrients. This paper takes a look at the complexities of these interactions and provides a new ecosystem model that uses these interactions to improve accuracy of carbon and nitrogen cycle estimations.

The Impact

The results of this study show that ecosystem responses to global change may hinge on the balance between a plant’s ability to decompose soil organic matter and a plant’s efficiency at exploring surrounding soils for physically protected nutrients. This research ultimately highlights the importance of dynamically linking plants and microbes in terrestrial biosphere models.

Summary

Nutrients in soils can be protected in many ways. For instance, chemical composition of soil can make it energetically demanding to decompose organic matter, or nutrients can be easily decomposed but protected behind some kind of physical location or barrier. Plants and their root fungus often determine these factors, and have adapted specialized tactics for gathering nutrients in these environments. This paper describes a new model created to account for plant-microbe symbioses for better estimations of their effects in global land models.

Principal Investigator

Joshua B. Fisher
UCLA, JPL
joshbfisher@gmail.com

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

DOE BER Environmental System Science (formerly Terrestrial Ecosystem Science) program and the NSF Ecosystem Science program.

References

Sulman, B.N., et al. "Feedbacks between Plant N Demand and Rhizosphere Priming Depend on Type of Mycorrhizal Association." Ecology Letters 20 (8), 1043-1053  (2017). https://doi.org/10.1111/ele.12802.