1.1.3 Carbon Cycle (Local)

Front 1

Reservoirs

Back 1

Atmosphere

Plants

Food web (land & sea)

Soil organic C

Fossil fuels

Sedimentary rocks

Shellfish and corals

Deep ocean sediments

Deep ocean currents

Phytoplankton

Ocean surface

Front 2

Flows

Back 2

Erupting volcanoes

Burning fossil fuels

Respiration

Photosynthesis

Diffusion

Decomposition

Weathering & erosion

Sinking

Rock cycle the

Front 3

The transfers in the carbon cycle act to...

Back 3

drive and cause changes in the carbon cycle over time

Front 4

Photosynthesis

Back 4

Carbon Dioxide + Water → Oxygen + Glucose

Plants sequester carbon and reduce the potential impacts of climatechange. Chlorophyll in the leaves of the plant react with CO₂, to create the carbohydrate glucose. Photosynthesis helps to maintain the balance between oxygen and CO₂ in the atmosphere.

Front 5

Respiration

Back 5

Oxygen + Glucose → Carbon Dioxide + Water

During the day, plants photosynthesise, absorbing significantly more CO₂ than they emit fromrespiration. During the night they do not photosynthesise but they do respire, releasing moreCO₂ than they absorb. Overall, plants absorb more CO₂ than they emit, so are net carbondioxide absorbers (from the atmosphere) and net oxygen producers (to the atmosphere).

Front 6

Combustion

Back 6

When fossil fuels and organic matter such as trees are burnt, they emit CO₂ into the atmosphere, that was previously locked inside of them. This may occur when fossil fuels are burnt to produce energy, or if wildfires occur.

Front 7

Decomposition -

Back 7

When living organisms die, they are broken down by decomposers (such as bacteria and detritivores) which respire, returning CO₂ into the atmosphere. Some organic matter is also returned to the soil where it is stored adding carbon matter to the soil.

Front 8

Diffusion

Back 8

The oceans can absorb CO₂ from the atmosphere, which has increased ocean acidity by 30% since pre-industrial times. The ocean is the biggest carbon store, but with carbon levels increasing seawater becomes more acidic which is harming aquatic life by causing coral bleaching. Many of the world’s coral reefs now under threat.

Front 9

Weathering and Erosion

Back 9

Rocks are eroded on land or broken down by carbonation weathering. Carbonation weathering occurs when CO₂ in the air mixes with rainwater to create carbonic acid which aids erosion of rocks such as limestone. The carbon is moved through the water cycle and enters the oceans. Marine organisms use the carbon in the water to build their shells. Increasing carbon dioxide levels in the atmosphere, may increase weathering and erosion as a result, potentially affecting other parts of the carbon cycle.

Front 10

Burial and Compaction

Back 10

When shelled marine organisms die, their shell fragments fall to the ocean floor and become compacted over time to form limestone. Organic matter from vegetation and decaying marine organisms is compacted over time, whether on land or in the sea, to form fossil fuel deposits.

Front 11

Carbon Sequestration

Back 11

Transfer of carbon from the atmosphere to other stores and can be both natural and artificial. A plant sequesters carbon when it photosynthesises and stores the carbon in its mass. Factories are also starting to use carbon sequestration in the form of Carbon Capture and Storage (CCS). CO₂ is captured and transported via pipeline to depleted gas fields and saline aquifers.

Front 12

Advantages of factory carbon sequestering

Back 12

● Can be fitted to existing coal power stations.

● Captures 90% of CO₂ produced.

● There is a demand for CO ₂ (Coca-Cola, Plant Growth, Beer etc.), so transport systems via pipeline in liquid form already exist.

● Potential to capture half the world’s CO₂ emissions.

Front 13

Disadvantages of factory carbon sequestering

Back 13

● High cost is the main restriction to the growth of CCS.

● Increases energy demand of power stations.

● May not be space to fit it to existing power stations.

● Economically viable in some cases as it is used to push oil out the ground, thus further increasing fossil fuel usage.

Front 14

The carbon cycle occurs on a local scale...

Back 14

in a plant, or in a sere

Front 15

A sere is...

Back 15

a stage of a vegetation succession and can relate to specific environments.

Front 16

Lithosere stages

Back 16

Bare rock colonised, by pioneer community, for example, lichens, mosses, bacteria, that can survive in hardy conditions, and need few nutrients.

Rock slowly weathered creating thin soil.

Plants die, creating humus, leading to a more fertile soil, grasses replace the mosses and lichens as the dominant species.

Grasses decrease in number, quick-growing shrubs become dominant.

Fast growing trees dominate.

Over time slower growing trees such as oak become dominant and form the climatic climax community.

Front 17

The climatic climax is...

Back 17

the final stage of the sere where environmental equilibrium is achieved. e.g. woodland or rainforest. When a sere reaches a climatic climax, the ecosystem is fully developed and stable.

Front 18

Examples of seres

Back 18

Lithosere - Bare rock

Halosere - Salty environment

Psammosere - Sand coastal environment

Hydrosere - Freshwater environment