EcologyInteractions Between Organisms and

their Environments

Mr. BroderickNC SCOS Goal 5

The organization of our world!

The earth is a biosphere

Ecosystems are the living and nonliving things in an area

Populations are a group of one type of organism living in an area

Hierarchy of Biology

• Molecules• Organelles

• Cells• Tissues• Organs• Organ systems• Organisms• Populations• Communities• Ecosystems

What is ecology?

• Ecology: The study of the relationship between organisms and their environment

• Example problems that ecology handles: – How do humans affect the atmosphere and

contribute to global warming? – How does the population of wolves in an area

affect the population of rabbits?– Do clownfish (Nemo!) and anemone benefit each

other?

Why does ecology matter?

• Ecology: The study of the relationship between organisms and their environment

Scenario: Imagine that there is an insect that lives on peanut plants growing on farms in Northampton County. Is there a way that we can limit insect damage to the peanut crops in order to decrease the price of peanuts at the store by 20 cents per pound?

Ecosystems

• Ecosystem: An area containing an interaction of living and non-living factors in an area/region

• Example ecosystems: – North Carolina forests (pine forests)– Coastal Plains of NC– Outer banks coastal water ecosystem– Lake Gaston ecosystem

What is in an Ecosystem?

• Abiotic Factors: The non-living parts of an ecosystem– Rocks, soil, temperature, gases in the air, light

• Biotic Factors: The living parts of an ecosystem– Plants, animals, bacteria, fungus• Producers: use light to make their own energy• Consumers: eat other organisms to obtain energy• Decomposers: break down dead organisms for energy

Biotic• Humans• Bacteria• Fungus• Plants• Insects• Amphibians• Reptiles• Mammals• Birds

Abiotic• Water• Soil• Wind or Air• Gases

– oxygen, carbon dioxide, nitrogen

• Temperature• Sunlight• pH

– Acid or base

Abiotic or Biotic?

Biotic (plant)

Abiotic (rainwater)

Abiotic or Biotic?

• The air temperature is 45 degrees F = • The soil is made of rocks and minerals =• A bird lays eggs =• Bacteria break down dead organisms = • The pH or the water is 2 (acidic) =

abioticabiotic

abiotic

bioticbiotic

Abiotic or Biotic?Biotic Biotic BioticAbiotic

Which of the following is a relationship between abiotic and biotic factors?

A) The rain on an open field washes away soilB) A hawk hunts a mouse and swoops down into

the forest for the killC) A lake has very acidic water which causes

many fish populations to dieD) A deer grazes in a field of grasses

Abiotic

Biotic

A scientist performs an experiment to see if acids have an effect on the health of a particular type of plant. Three sets of plants were treated with acidic solutions of known pH while the control set was treated with a solution of neutral pH 7.

What is the best conclusion for this experiment?

A. Acid has no effect on the health of this type of plant

B. High acidity is helpful to this type of plant

C. Low acidity is harmful to this type of plant

D. High acidity is harmful to this type of plant

Energy Transfer in an Ecosystem

Food Chains

• A food chain shows the flow of energy between the organisms in an environment

Food Chains

• Notice that the arrow points from the organism being eaten to the organism that eats it.– Like the burger you eat goes into you

Plants Cow (burger) Human

What do the arrows in the food chain below indicate?

A. SunlightB. Energy flowC. Heat transferD. Toxins

What is energy?

• The energy that is transferred in an ecosystem is stored in carbon-compounds, or organic compounds.– Organic compounds: molecules that contain a

carbon atom• Carbohydrates: glucose, starch, cellulose (mostly plants)• Proteins: the muscles of animals (steak!)• Fats: in muscle of animal tissues (fatty steak!)

Food Webs• When we put many food chains together in

one ecosystem, it is called a food web• Food webs show the direction that energy flows

in an ecosystem.

Energy Moves in a Food Web

Plants make glucose from light

Some animals get glucose from plants

Other animals get energy from the fat and protein in other animals

Parts of a Food WebProducers: organisms that use light to store energy in organic compounds. (examples: plants, algae, phytoplankton)

Consumers: organisms that eat other organisms to get organic compounds that

they use for energy (examples: humans, cows, insects, birds…)

3 ͦconsumers: organisms that eat 2 ͦconsumers for energy2 ͦ consumers: organisms that eat 1 ͦconsumers for energy1 ͦconsumers: eat producers to obtain energy compounds

Parts of a Food Web

• Where are the producers in the food web below?

Parts of a Food Web

• Where are the consumers in the food web below?

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Which of the following organisms is a primary consumer in the ecosystem shown?

A. HawkB. RabbitC. Mountain lionD. Frog

Population Impacts in a Food Web

• If the population of organisms at any level of the food web changes, it will affect the population at other levels

• If the population of producers decreases, then the population of primary consumers will decrease if they don’t have enough food.

• If the population of primary consumers decreases, then…-The producers will increase because there are less consumers eating them-The secondary consumers will decrease because there is less food for them

Which organism would be most affected if the cricket population decreased?

A. SnakeB. DeerC. FrogD. Hawk

Energy Pyramids

• Energy Pyramids show the amount of energy at each level of a food web– Trophic Level: the total amount of energy in all

organisms at one level in the food web.

Energy Pyramids

• More energy at the bottom, decreases as the pyramid moves up the food web

More Energy

Less Energy

Energy Pyramid Labels

Producers

Tertiary Consumers

Primary Consumers

Secondary Consumers

Energy Transfer in Energy Pyramids

• Each trophic level of the energy pyramid supplies energy to the level above it.

• Each transfer loses 90% of the energy• Only 10% of the energy at a level is passed to

the next level up!

100%

10%

1%

0.1%

Energy Transfer (calories)

1,000 calories

1 calorie

100 calories

10 calories

Energy Transfer in Energy Pyramids

• We can say that the energy transfer from level to level is inefficient– (not a lot of the energy at each level makes it up)

• This means that there can’t be many levels ina food web or pyramid– The amount of energy decreases, and it cannot

typically support organisms at higher levels than tertiary consumer

Energy Transfer and Flow

How does energy enter the food web?

Better question… where does the weight of a producer come from?

How does this... become this?

Carbon Dioxide

Water Glucose OxygenSunlight

Photosynthesis

Photosynthesis: a toxin process that occurs in producers and converts light, carbon dioxide, and water into glucose (sugar) and oxygen

Light CO2 H2O

Glucose O2

Starch

Fat(nuts)

How do consumers get energy?

• Digestion of organic molecules– Consumers eat other organisms to obtain organic

molecules, which are forms of stored energy.– Energy is stored in the bonds of the molecules.

The Carbon Cycle

Carbon Cycle

• Carbon is found throughout the environment– Carbon is found in the atmosphere and in water as

carbon dioxide (CO2)– Carbon is found in organisms as organic

molecules, like glucose (sugars) and fats– Carbon is found buried in the ground as fossil fuels

CO2

C6H12O6

CO2

Greenhouse Effect and Global Warming

Greenhouse Effect• Heat is trapped near the Earth’s surface

because once light gets in, it warms the surface but cannot escape out of the atmosphere.– It is trapped by the gases in the atmosphere, like

CO2

Excess CO2 Enhanced Greenhouse Effect Global Warming

GLOBAL WARMING•The Earth has been warming on average.•Could be due to increased CO2 emissions into the atmosphere, which enhances the greenhouse effect and traps extra heat.