Concepts

Measurement of ¹⁴C content to distinguish between modern plant-derived and ancient shale-derived organic carbon sources

Vertical distribution of plant nutrient uptake from soil surface through saprolite to bedrock

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

Organic matter particles larger than 1 mm, including intact leaves and larger detrital fragments

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

the rate of nutrient excretion per unit body mass of an organism

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

Organic material found in pond sediments that serves as nutrient storage compartment

Distinct layers in soil profile with different physical and chemical properties

Use of 87Sr/86Sr ratios to trace sources of nutrients and water in ecological systems