Soils are crucial for life on earth, helping regulate the global climate on a planetary scale, and supporting many important ecosystem services on local scales. Carbon and nitrogen cycling are two important processes in soil that can affect the function of soil on many scales. In the Schimel Lab, we study how natural gradients and human activity control C and N cycling in soil. We are particularly interested in understanding controls on the biology and activity of soil microbes, as these microbes are key drivers of soil C and N cycling. We combine experimental and observational studies with theoretical modeling to connect biology and chemistry at microbial scales to landscape-scale functions of soils and ecosystems. Our study systems range from the grasslands of California to the artic tundra to farms in Ireland.