nutrient cycles pp

8/9/2019 Nutrient Cycles PP

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Nutrient Cycles


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Nutrient Cycles

Nutrients are essential to life but have a limited supply(not a continuous input like energy).

Life is dependent on the recycling of essential elements -nutrients.

Living organisms consume nutrients as food and wastesare released back into the ecosystem.

When organisms die the nutrients are recycled bydecomposers, nutrients are released into the air, water

or soil and can then be used by other organisms(producers)

Some examples of nutrient cycles are the carbon,nitrogen & phosphorus cycles


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Carbon Cycle

Carbon is found in all living things

The carbon cycle is a Closed system

there is always the same amount of carbonin the world, just in different forms.

Carbon enters food chains through the

process ofphotosynthesis and is released

into the atmosphere via respiration.


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Photosynthesis

Plants combine carbon dioxide and hydrogen

from water to make glucose (sugars) Occurs in the presence of light and chlorophyll

Oxygen is released into the atmosphere

Glucose is stored in plant tissues or used for

energy

Carbon dioxide (CO2) + Water (H20)light & chlorophyll glucose + oxygen

(02)


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Respiration

Occurs at all times in cells

Releases energy from glucose

Carbon dioxide and water are waste products release into environment

Oxygen taken in

P

lants use glucose they create throughphotosynthesis, animals use glucose they gainfrom plants (directly or indirectly)

Glucose + Oxygen (O2) Carbon dioxide (CO2) + Water (H2O) + energy


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Water (H2O)

Carbon dioxide (CO2)

Oxygen (O2)

Food

RESPIRATION

Glucose


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Nitrogen Cycle Nitrogen is needed by all organisms for the manufacturing of

protein.

Approx 78% of the air is Nitrogen (N2), however, only certain

nitrogen-fixing bacteria can use nitrogen in this form.

Nitrogen-fixing bacteria are found in the soil or in root nodules oflegumes.

Bacteria convert N2 into nitrogen forms that plants can absorb

(nitrates), plants then convert nitrates to protein.

Protein from plants consumed by consumers (animals).

Decomposers return nitrogen to soil from dead organisms andwastes

Denitrifying bacteria in the soil release nitrogen back to the

atmosphere as N2

The amount of available nitrogen directly affects the amount of plant

growth


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Phosphorus cycle

Phosphorus is required in greater amountsby organisms than nitrogen but there ismuch less. Availability limits plant growth

Slow cycle - released slowly into the soiland water from weathering of rocks.

Phosphates dissolved in soil are absorbed

by plant roots, then passes through foodchain

Decomposers recycle back to soil


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nutrient cycles pp

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