Question

key question: how does the cycling of carbon through the abiotic and biotic components of ecosystems make carbon continually available to organisms? carbon is an essential element of life and is incorporated into the organic molecules that make up living organisms. large quantities of carbon are stored in sinks, which include the atmosphere as carbon dioxide gas (co₂), the ocean as carbonate and bicarbonate, and rocks such as coal and limestone. carbon cycles between the biotic and abiotic environment. carbon dioxide is converted by autotrophs into carbohydrates via photosynthesis and returned to the atmosphere as co₂ through respiration (fluxes). these fluxes can be measured. some of the sinks and processes involved in the carbon cycle, together with the carbon fluxes, are shown below. humans intervene in the carbon cycle through activities such as combustion and deforestation. 1. add arrows and labels to the diagram above to show: (a) dissolving of limestone by acid rain (b) release of carbon from the marine food chain (c) mining and burning of coal (d) burning of plant material. 2. (a) name the processes that release carbon into the atmosphere: ______ (b) in what form is the carbon released? ____ 3. name the four geological reservoirs (sinks), in the diagram above, that can act as a source of carbon: (a) ____ (c) ____ (b) ____ (d) ____ 4. (a) identify the process carried out by algae at point a: ____ (b) identify the process carried out by decomposers at b: ____ 5. what would be the effect on carbon cycling if there were no decomposers present in an ecosystem? ______

Explanation:

Step1: Analyze carbon - related processes

We need to understand different carbon - releasing and cycling processes based on the carbon - cycle knowledge.

Step2: Answer question 1

(a) Add an arrow from limestone to the atmosphere with the label "Dissolving of limestone by acid rain releases carbon as $CO_2$".
(b) Add an arrow from the marine food - chain (e.g., from the fish icon) to the atmosphere with the label "Release of carbon from the marine food chain".
(c) Add an arrow from coal to the atmosphere with the label "Mining and burning of coal releases carbon as $CO_2$".
(d) Add an arrow from carbon in plant and animal tissues to the atmosphere with the label "Burning of plant material releases carbon as $CO_2$".

Step3: Answer question 2

(a) Processes that release carbon into the atmosphere are respiration, combustion, decay of organic matter (by decomposers), and release from the marine food chain.
(b) Carbon is released as carbon dioxide ($CO_2$).

Step4: Answer question 3

(a) Coal
(b) Limestone
(c) Soil
(d) Ocean

Step5: Answer question 4

(a) Photosynthesis (algae take in $CO_2$ and convert it into organic carbon compounds)
(b) Decomposition (break down organic matter and release carbon back into the soil and atmosphere)

Step6: Answer question 5

If there were no decomposers, the carbon stored in dead organisms and waste would not be recycled back into the ecosystem. Organic matter would accumulate, and less carbon would be available for plants to use in photosynthesis. The carbon cycle would be disrupted, and the flow of carbon between the biotic and abiotic components would be severely hampered.

Answer:

1.
(a) Added arrow from limestone to atmosphere labeled "Dissolving of limestone by acid rain releases carbon as $CO_2$"
(b) Added arrow from marine food - chain to atmosphere labeled "Release of carbon from the marine food chain"
(c) Added arrow from coal to atmosphere labeled "Mining and burning of coal releases carbon as $CO_2$"
(d) Added arrow from carbon in plant and animal tissues to atmosphere labeled "Burning of plant material releases carbon as $CO_2$"
2.
(a) Respiration, combustion, decay of organic matter (by decomposers), release from marine food chain
(b) Carbon dioxide ($CO_2$)
3.
(a) Coal
(b) Limestone
(c) Soil
(d) Ocean
4.
(a) Photosynthesis
(b) Decomposition

1. Carbon stored in dead organisms and waste would not be recycled, organic matter would accumulate, and the carbon cycle would be disrupted.