Quantity and composition of POM and MAOM in 156 soil samples collected from 20 National Ecological Observatory Network (NEON) sites in 2019

While it is generally assumed that particulate organic matter (POM) and mineral associated organic matter (MAOM) have distinct biogeochemical characteristics, it remains unresolved where and why POM and MAOM differ in their composition and relationships to total SOM decomposition among heterogenous soils. To address these questions, we analyzed elemental, isotopic, and chemical composition, including diffuse reflectance infrared Fourier transform (DRIFT) spectra, of POM and MAOM in 156 soil samples collected from 20 National Ecological Observatory Network (NEON) sites spanning diverse ecosystems (tundra to tropics) across North America in 2019. We used a classic size separation method for POM (53–2000 µm) and MAOM (< 53 µm) following chemical dispersion.