Concepts

CO2 efflux from soils to atmosphere representing combination of autotrophic respiration (root respiration) and heterotrophic respiration (microbial decomposition)

The cycling of chemical elements between living organisms and the physical environment, particularly carbon and nitrogen cycles

Human-induced nitrogen input that has doubled biologically-available nitrogen on Earth

Mechanisms by which organic carbon is protected from decomposition in soils through physical, chemical, and biological processes

The microbiome's ability to extract energy from dietary sources

Measure of soil acidity/alkalinity that may influence plant phenotype expression

Accounting framework that tracks carbon inputs, transformations, and outputs in environmental systems to quantify net carbon fluxes

The interplay of belowground, microsite-scale biological, physical, and chemical processes that intersect to drive whole-ecosystem functioning

The constraint of microbial activity and carbon respiration by water availability in soil systems

Geographic patterns in biodiversity and chemical diversity across latitudinal and environmental gradients

Energy content of plant materials measured as calories per gram of ash-free oven-dry weight

Activity of enzymes secreted by soil microorganisms that catalyze decomposition of organic matter and provide assimilable carbon and nitrogen compounds

Total amount of living microbial tissue in soil measured as carbon and nitrogen content