Unit 10Ecology

Energy, Cycles, & Human Impact

The sun is the main energy source for life on earth!

Where does most of the energy in an ecosystem originate from?

There are 2 ways:

1. Autotrophs: Organism that captures energy from sunlight or inorganic substances to produce its own food; also called producers.

How do organisms get their energy?

There are 2 ways:

2. Heterotrophs: Organism that cannot make its own food and gets its nutrients and energy requirements by feeding on other organisms; also called consumers.

How do organisms get their energy?

Herbivores: Eat Plants

What are 6 different types of consumers?

Carnivores: Eat Meat

What are 6 different types of consumers?

Omnivores: Eat plants & meat

What are 6 different types of consumers?

Detritivore: Eat organic matter/poop – detritus

What are 6 different types of consumers?

Scavenger: Eats animals that are already dead.

What are 6 different types of consumers?

Decomposers: Breaks down all the rest (bones, feathers, dead

trees…)

What are 6 different types of consumers?

What is the difference between a food chain & food web?

Food Chain: A simple model that shows how energy flows through an ecosystem.

What is the difference between a food chain & food web?

Food Web: A model representing the MANY interconnected food chains and pathways in which energy flows through a group of organisms.

What are trophic levels?

Each step in a food chain/web is called a

trophic level.

What are ecological pyramids?Ecological Pyramid: Another model used to show how energy flows through ecosystems.

Can show:

* Amount of Energy

* Amount of Biomass

* Number of organisms

What are ecological pyramids?Ecological Pyramid: Another model used to show how energy flows through ecosystems.

What is this one showing?

* Amount of Energy

* Amount of Biomass

* Number of organisms

What are ecological pyramids?

What is this one showing?

* Amount of Energy

* Amount of Biomass

* Number of organisms

Biomass: The total mass of living matter at

each trophic level.

What are ecological pyramids?

What is this one showing?

* Amount of Energy

* Amount of Biomass

* Number of organisms

What is the 1/10th Rule?* The reason that each trophic level can support only 1/10 of the amount of living tissue as the level below it is because each trophic level harvests only about one tenth of the energy from the level below.

* Only 10% of energy moves up to the next trophic level

The rest of the energy (90%) is LOST as HEAT• Running ● Hunting for food• Breathing ● Sleeping• Reproducing ● Maintaining body heat

What is the 1/10th Rule?

100,000 J

10,000 J

1,000 J

100 J

10 J

1 J90% Lost

10% RULE:Only 10% of the energy at one trophic level moves up to the next trophic level. The other 90% is lost as heat.

What are 4 different types of cycles in the biosphere?Nutrient: Is a chemical substance that an

organism obtains from the environment to sustain life.

Biogeochemical Cycle: Cycles that involves organisms (bio), geological processes (geo), and chemical processes (chemical).4 Main Types:

* Water Cycle* Carbon Cycle* Nitrogen Cycle* Phosphorus

Cycle

What is the Water Cycle?Water is constantly

evaporating into the atmosphere from bodies of water, soil, & organisms.

Transpiration: When water

evaporates from the surface of plants.

What is the Carbon Cycle?* All living things have carbon in them. * Carbon is in proteins, carbohydrates, lipids, nucleic acids.* Carbon dioxide is used by plants to make energy

(carbohydrates)* Carbon is released into the atmosphere when we burn fossil

fuels.* Carbon can be trapped in the ground as coal, oil, and gas

deposits

What is the Nitrogen Cycle? Most of the atmosphere has Nitrogen in it (78%) Organisms CAN’T use Nitrogen GAS!!...so it needs to be

“fixed” “Fixing” nitrogen, is turning it from a gas into NITRATES

(usable)Nitrogen Fixation: Process in which nitrogen gas is captured and converted into a form plants can use (nitrates)

How is Nitrogen “fixed”?There are 2 main ways to “Fix” nitrogen

1.Lightning changes nitrogen gas into nitrates

How is Nitrogen “fixed”?There are 2 main ways to “Fix” nitrogen

2. Nitrogen Fixing Bacteria changes gas into nitrates

Found on roots of Legums only!

* Peanuts * Peas * Clover * Beans * and many more…

What is the Phosphorus Cycle?

• Phosphorus is essential for growth & development• When organisms poop or die, they return phosphorus back to the cycle.

Can there be too much of a good thing?• YES!Eutrophication: Occurs when fertilizers, animal waste, sewage, or other substances rich in Nitrogen & Phosphorous flows into waterways, causing algae growth.

What is biomagnification?Biological Magnification: Is

the increasing concentration of toxic substances in organisms as trophic levels increase in a food chain or food web.

What is an example of the use of a toxin that caused biomagnification?

• DDT: A pesticide used between the 1940s - 1970s

We sprayed DDT EVERYWHERE!

What is an example of the use of a toxin that caused

biomagnification?

DDT causes bird eggs to be brittle, and break when parents try to sit on them to incubate them

What is an example of the use of a toxin that caused biomagnification?

When fossil fuels are burned in industrial processes, sulfur dioxide is released into the atmosphere.

Automobile exhaust releases nitrogen oxides into the air.

In the atmosphere, these compounds react with water to form sulfuric acid & nitric acid, which eventually fall back to earth in the form of “acid rain”.

Acid Rain

Effects of Acid Rain

Effects of Acid Rain

Clearing land for development◦ For example, deforestation of tropical rain forests.

Habitat Destruction

Southeastern US◦ Examples: Fire ants, Kudzu

Great Lakes region◦ Example: Zebra Mussels

Introduced (Invasive) Species

Fire Ants

Kudzu

Zebra Mussels

Global Warming

Increased carbon emissions from vehicles, industrial pollution, power generating plants have increased the amount of carbon dioxide in the atmosphere

This has occurred since the Industrial Revolution, but has recently seemed to speed up.

Is this just part of a natural cycle, or will it keep going?

Global Warming

Ice cores provide information on CO2 levels from the past.

Ice Cores

Global Warming

What is ecological succession?

Ecological Succession - The series of changes that occur in a community over time.

What is ecological succession?

What are the 2 types of ecological succession?

1st Primary Succession – Occurs when there was no soil for regular plants to grow.

Examples: Volcano eruptions & glaciers retreating

What are the 2 types of ecological succession?

Volcanoes can create

new islands...

No soil isAvailable for

plants to grow

What are the 2 types of ecological succession?

When glaciers retreat, they

leave exposed rock…

No soil for plants to grow

in.

How is soil created so plants can grow in the area?

Pioneer Species: A species that will colonize previously uncolonized land. Are organisms that colonize barren rock or lava during ecological succession. They are the FIRST to arrive!

They physically break up the rocks, extract minerals, and provide organic matter that will decompose and become the soil for later successional species.

How is soil created so plants can grow in the area?

Example: Lichens

Lichens: A symbiotic relationship between a fungus and an algae.

How is soil created so plants can grow in the area?

Lichens help break rocks to form soil so that other plants can grow there later.

What is a climax community?

Climax Community: Stable, mature ecological community with little change in the composition of species. This is when the community reaches equilibrium, and change very little over time.

2nd Secondary Succession: Orderly change that occurs in a place soil remains after a community of organisms has been removed.

What are the 2 types of ecological succession?

• When a disturbance changes a community without removing the soil, secondary succession will follow.

What are the 2 types of ecological succession?

What are some examples of secondary succession?

Examples of Secondary Succession – Forest Fire– Farm land– Flood– Hurricane– Logging

Occurs after a climax community has been destroyed…

soil is already there.

The End