Biodiversity. This term is frequently used to describe the distribution and heterogeneity of species in a particular region or ecosystem. Biodiversity plays a significant role in biogeochemical cycles throughout the Earth’s systems. In an undertaking beginning this year, Adam Martiny will lead a research project focusing on biological controls in the oceans. Awarded funding from the National Science Foundation’s Dimensions of the Biodiversity program, this project represents a novel, integrated approach to understanding the significance of biodiversity in today’s changing environment.

Martiny’s project will focus on the Redfield Ratio, which is the ratio of nitrogen to phosphorus in seawater. Understanding how biodiversity regulates the Redfield ratio will provide important insights into the role of biodiversity in regulating global nutrient cycles. Ultimately, this understanding will lead to a model of biogeochemical cycles, which will allow scientists to investigate the consequences of global change on the ocean ecosystem.

This study will greatly expand knowledge of the genomic diversity among ocean microbes and how this diversity affects biogeochemistry. The stoichiometry (essentially the ratio) of the ocean’s microbes is a parameter that nearly every chemical or biological oceanographer uses, from converting measurements made in one element to another, to estimating regional and global nitrogen budgets. The Martiny project will involve field observations of taxon-specific stoichiometry and growth rates, genomic analysis, and laboratory chemostat experiments to improve understanding of how ocean taxonomic, genetic, and functional biodiversity control the stoichiometry of the surface ocean plankton. Analyses of these data would lead to a mechanistic understanding of variations in the Redfield ratio, both spatially and temporally. The research also has important implications for the global carbon budget and any changes that might result from climate change.