Ecological Organization and Matter Cycles

Ms. HenriksenBiology

What is Ecology?

• The scientific study of interactions among organisms and between organisms and their environment, or surroundings.

• Study how living things interact with other living things and with non-living things.

Abiotic factors = nonlivingBiotic factors = living

• non-living components in the environment…– light – water– wind– nutrients in soil– heat– solar radiation– atmosphere, etc.

• Living organisms…– Plants– Animals– microorganisms in soil, etc.

Levels of organization

Levels of Organization• Species - group of similar organisms that can breed

and produce fertile offspring• Population- group of individuals of the same species

that live in the same area• Community – group of different populations that live

together in a defined area• Ecosystem - collection of all the organisms that live in

a particular place, together with their nonliving environment

• Biome - group of ecosystems that have the same climate and dominant communities

• Biosphere - part of Earth in which life exists including land, water, and air or atmosphere

Cycles of Matter• Matter: anything that has weight and takes up

space.

• Matter cannot be used up.• It is transformed.

• Matter is recycled within and between ecosystems.

• Example: you eat food, it is assembled into living tissue or passed out as waste.

Nutrient Cycles

Nutrients: all the chemical substances that an organism needs to survive.

“Building Blocks”

1. To build tissues2. To carry out life’s essential functions

1. You are floating in the air as a molecule of carbon dioxide.2. You are soon absorbed by a leaf on a blueberry bush during

photosynthesis.3. You then become part of a carbohydrate molecule and are used to

make fruit.4. You are now in a blueberry that is eaten by a moose.5. Within a few hours, you are passed out of the moose’s body.6. A dung beetle comes along and swallows you.7. You then become part of the body tissue of a mouse, which eats

the beetle.8. Next, you enter the body of an owl, when it eats the mouse.9. Finally, you are released back into the atmosphere when the owl

exhales.10. You are floating in the air as a molecule of carbon dioxide.

Diagram of the carbon cycle pg

How does carbon move to the air?

How is carbon cycled back to the soil?

How is carbon stored in water?

The Carbon Cycle

• Carbon: an important part of living tissue

– Animal skeletons are made of calcium carbonate– Carbon dioxide is used for respiration (breathing)

and photosynthesis – Decomposition releases carbon into the soil where

it is changed into coal and petroleum

Diagram of the nitrogen cycle• What

organisms are most important for fixing nitrogen into a form that other can use?

• Where do we find these organisms

The Nitrogen Cycle

• All living organisms need nitrogen to make amino acids, which build proteins

• 78% of the atmosphere is made of nitrogen gas

• Wastes and dead organic matter contain ammonia, nitrate and nitrite ions

• Nitrate is in plant fertilizers

The Nitrogen Cycle

• Nitrogen fixation: bacteria in soil and on the roots of plants (legumes) convert nitrogen gas into ammonia.

• Producers cannot use nitrogen gas, but can use ammonia.

• Denitrification: bacteria in soil convert nitrates into nitrogen gas and it enters the atmosphere again.

Diagram the phosphorous cycle• Is

phosphorus ever cycled into the atmosphere?

The Phosphorous Cycle

• Living organisms need phosphorous to make DNA or RNA (carry genetic info)

• Phosphorous is not common in the biosphere and never enters the atmosphere.

• Found in rock, soil minerals and ocean sediments.

Nutrient Limitation

• Primary productivity: how fast producers create organic matter.

• A Limiting Nutrient: a nutrient that is scarce or cycles slowly, limiting primary productivity.

Too much of a good thing…

• Fertilizers are used to speed up plant growth.• Too much of a nutrient will cause an algal

bloom• Algal bloom: algae grows quickly, without

enough consumers to eat it up.• Algae takes over the surface of the water.– (p.80, figure 3-16)

• Why do living organisms need nutrients?_______________________________________

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Questions…

Essential Questions

• What different levels of organization do ecologists study?

• How to biotic and abiotic components of an ecosystem interact?

Essential Questions

• How does matter move among the living and nonliving parts of an ecosystem?

• How is the phosphorus cycle different than the other cycles?

• Which cycle relies heavily on bacteria?• Which cycle do humans impact most heavily?• How are nutrients important in living systems?