Describe Matter Movement in Ecosystems - Biology

Cellular respiration. All organisms break down organic compounds and release $CO_2$.

Decomposition and respiration releasing $CO_2$. Decomposer respiration releases carbon stored in wood as $CO_2$.

Low oxygen (anaerobic) soils or sediments. Denitrifying bacteria use nitrate as an electron acceptor without oxygen.

Matter cycles; energy flows one-way through trophic levels. Matter is recycled while energy is lost as heat at each trophic level.

Long-term storage of carbon in biomass, soils, oceans, or rocks. Carbon is removed from active cycling and stored long-term.

Biogeochemical cycle. Elements move through biological, geological, and chemical processes.

Uptake of $NO_3^-$ or $NH_4^+$ to build organic nitrogen compounds. Plants absorb inorganic nitrogen to synthesize proteins and nucleic acids.

Decomposers convert organic nitrogen to $NH_3$/$NH_4^+$. Releases nitrogen from dead organisms back to the soil.

$CO_2$ → grass → rabbit → wolf. Shows carbon moving through a complete food chain from producer to tertiary consumer.

The rate of movement of matter between reservoirs. Measures how fast matter moves from one pool to another.

A storage location for matter, such as soil, biomass, or atmosphere. These pools hold matter temporarily during biogeochemical cycles.

Bacterial conversion of $NO_3^-$ to atmospheric $N_2$ (and $N_2O$). Returns nitrogen to the atmosphere, completing the cycle.

$N_2$ → fixation → $NH_4^+$/$NO_3^-$ → assimilation. Shows nitrogen conversion from atmospheric gas to bioavailable form to organic compounds.

Denitrification. Bacteria reduce nitrate to nitrogen gas in oxygen-poor conditions.

Phosphorus cycles via rocks/soil; it has no major atmospheric gas phase. Phosphorus lacks a gaseous form and moves only through solid/liquid phases.

Ammonification (mineralization). Bacteria break down organic nitrogen compounds to release ammonium.

Nitrification. Bacteria oxidize ammonium to nitrate in well-oxygenated soil.

Sedimentary rocks and carbonate minerals. These geological formations hold carbon for millions of years.

The movement of nitrogen among atmosphere, soil, water, and organisms. Nitrogen moves between air, soil, water, and living organisms.

Biomass. Measures the total amount of living organic matter present.

Macronutrients are needed in larger amounts; micronutrients in trace amounts. Macronutrients like carbon and nitrogen are needed in large quantities.

Accumulation in food webs; it is not a nutrient cycle. Toxins concentrate up food chains rather than cycling through ecosystems.

Conversion of atmospheric $N_2$ into ammonia ($NH_3$)/$NH_4^+$. Breaks the strong triple bond in $N_2$ to make bioavailable nitrogen.

Nitrogen-fixing bacteria (free-living or in root nodules). They have the enzyme nitrogenase that converts atmospheric $N_2$.

Bacterial conversion of $NH_4^+$ to $NO_2^-$ then $NO_3^-$. Oxidizes ammonia to nitrites then nitrates in aerobic conditions.

Matter is incorporated into hawk biomass and released as waste and $CO_2$. Matter is either assimilated into tissues or excreted as waste.

Carbon dioxide ($CO_2$) from the atmosphere. Plants fix atmospheric $CO_2$ during photosynthesis to make glucose.

Nitrate ($NO_3^-$) or ammonium ($NH_4^+$) in soil. These are the bioavailable forms of nitrogen that plant roots can absorb.

Phosphate ions ($PO_4^{3-}$) from weathered rock/soil. Rock weathering releases phosphate ions that plants can uptake.