BIOL150 Chapter Notes - Chapter 12: Positive Feedback, Cellular Respiration, Eria
Document Summary
Section 12. 10 how do nutrients cycle through ecosystems. Carbon, nitrogen, phosphorus, calcium and other elements act as nutrients. Atoms are constantly reused as they move through trophic levels, but also spend time suspended in air, dissolved in water, or held in soil. Biogeochemical cycle is the path elements take from abiotic systems through producers, consumers, and decomposers and back again (figure 12. 27) If plant tissue is eaten, nutrients are passed to consumer food web; if plant tissue dies, nutrients enter compartment labeled detritus . Primary decomposers like bacteria and archaea take up dead animal bodies and excretions: decomposers and released carbon containing compounds combine to form soil organic matter. Soil organic matter is complex mixture of partially and completely decomposed detritus: completely decayed organic material is called humus because it is rich in family of carbon-containing molecules called humic acids.