EcologyInteractions Between Organisms and their Environments

Lesson #1: Living and non-living parts of an Ecosystem

• Objectives– Identify abiotic and biotic factors in a given

description of an ecosystem interaction– Generate an example relationship using abiotic

and biotic factors– Determine if a solution is acidic, basic, or neutral

given its pH– Set-up an experiment to test the effect of pH on

the sprouting of a lima bean• Develop hypothesis, procedure

Key Vocabulary to Define

• Ecosystem• Abiotic• Biotic• pH• Acidic• Basic• Neutral

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?

How do we study environments?

• Quadrant Studies: Tracking changes in a small section of the environment

How do we study environments?

• Sampling: Only measuring a small, random part of an environment

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

Energy Transfer in an Ecosystem

NCSCOS 5.02b

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

• 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 Web

• Producers: organisms that use light to store energy in organic compounds. – (examples: plants, algae, phytoplankton)

Parts of a Food Web

• Where are the producers in the food web below?

Parts of a Food Web

• Consumers: organisms that eat other organisms to get organic compounds that they use for energy – (examples: humans, cows, insects, birds…)

Parts of a Food Web

• Where are the consumers in the food web below?

Parts of a Food Web

• Tertiary consumers: organisms that eat secondary consumers for energy

• Secondary consumers: organisms that eat primary consumers for energy

• Primary consumers: organisms that eat producers to obtain energy compounds

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

How is energy stored and transferred in an ecosystem?

A. In lightB. In oxygen and carbon dioxideC. In carbon compounds like glucoseD. In the process of decomposition

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

Population Impacts in a Food Web

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

Population Impacts in a Food Web

• 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!

Energy Transfer (percents)

100%

0.1%

10%

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

Why are there a limited number of energy levels in an energy pyramid or food web?

A. Energy transfer is very efficientB. Energy is captured as heatC. Energy transfer is inefficientD. Energy is not transferred in a food web

Energy Transfer and Flow

NCSCOS 5.02a, 2.05bc

How does energy enter the food web?

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

How does this... become this?

Photosynthesis

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

Carbon Dioxide

Water Glucose OxygenSunlight

More Photosynthesis

a. Photosynthesis removes carbon dioxide from the air.

b. The carbon dioxide in the air is the building block for glucose.

c. The light energy helps bond CO2 and H2O together to make glucose.

• The energy in light is now stored in the glucose molecule

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

NCSCOS 5.02a

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

Carbon Cycle

• Carbon is cycled, or moves1) Atmosphere: Carbon is in the form of CO2

CO2

Carbon Cycle

2) Producers: Use photosynthesis to make sugars from CO2 in the atmosphere (carbon is moved!)

C6H12O6

Carbon Cycle

3) Consumers: Eat organic molecules and release CO2 into the atmosphere during respiration, or die and go into the soil

CO2

Carbon Cycle

4) Soil: decomposers break down organisms, releasing carbon into the atmosphere OR trapping it in the ground (fossils)

Carbon Cycle

5) Fossil Fuels: carbon from some dead organisms are trapped as fossil fuel until we burn it

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

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.

Global Warming

Excess CO2 Enhanced Global Warming

GreenhouseEffect

Relationships in an Ecosystem

NCSCOS 5.01

Symbiosis

• Symbiosis: a long-term relationship between two organisms in an ecosystem.

Types of Symbiosis

• Mutualism: both organisms benefit from their relationship

• Commensalism: one organism benefits, and the other is unaffected

• Parasitism: one organisms benefits, and the other is harmed

Symbiosis Summary

Relationship Type Species A Species B

Mutualism + +

Commensalism + 0

Parasitism + -

Name That Symbiosis• Leeches feed off of the lamprey below, and

eventually cause it to die.

Name That Symbiosis• A clown fish lives among the sea anemone.

The clown fish gains protection, but the anemone is neither harmed nor helped.

Name That Symbiosis• Ox-peckers live on the heads of the ox, eating

insects and keeping the ox clean. The birds also get a place to live.

Example: The Malaria Parasite

• Species: Plasmodium Vivax• Organism: Protist• Disease: Malaria, which is prevalent in Africa

A. Plasmodium Vivax is a one-celled organism that is transmitted to humans through the bite of the female Anopheles mosquito

B. It enters liver cells and begins to reproduceC. The reproductive cells infect blood cells.D. Which causes them to lyse or burst.E. The reproductive cells can be picked up by

another mosquito, where they reproduce (G) and are transmitted to another human (H)

Population Growth and Overpopulation

NCSCOS 5.03

Populations

• Population: the number of organism from one species that live in a specific area– Examples: the human population in different cities,

the squirrel population in a forest, the grass population in a meadow

Populations

• Populations are affected by many resources. These include:– The amount of food available in an area– The amount of sunlight (if it is a plant population)– The amount of water– The competition for food/shelter– The predators in an area

Population Growth Graphs

A: Slow growth as a population begins to grow

Birth Rate > Death Rate

Population Growth Graphs

B: Exponential growth as population grows rapidly

Birth Rate > Death Rate

Population Growth Graphs

C: Slow-down of growth as population maxes out its resources, like food, water, or light

Birth Rate > Death Rate

Population Growth Graphs

D: Population reaches the maximum number supported by environment, the carrying capacity

Birth Rate = Death Rate

Carrying Capacity

• Carrying Capacity: the maximum number of organisms in a population that are supported by the environment

Population Growth GraphsCarrying CapacityReaching Limit

of Resources

Exponential Growth, no limiting resources

Carrying Capacity

• Populations are typically limited by resources– They reach carrying capacity when there aren't

enough resources to keep growing. – Birth Rate = Death Rate.– Logistic Growth!

Unlimited Growth

• If there are no limiting resources, populations grow exponentially.

• Birth Rate > Death Rate

Decline

• If population birth rate < death rate, the population will go down!

Which of the following graphs shows a population that is free of limiting factors?

Which of the following graphs shows a population that has reached carrying capacity?

How would a scientists determine the growth rate of a population?

A. Birth Rate + Death RateB. Birth Rate – Death RateC. Birth Rate x Death RateD. Birth Rate / Death Rate

Click To Go Back and Analyze The GraphsIn Terms of Birth And Death Rates (with the class)

What statement best describes the population shown in the graph below?

A. Birth rate = Death rateB. Birth rate < Death rateC. Birth rate > Death rateD. Birth rate = 0

What statement best describes the population shown in the graph below at time “t”?

A. Birth rate = Death rateB. Birth rate < Death rateC. Birth rate > Death rateD. Birth rate = 0

Predator vs Prey

• Predator and Prey populations can affect one another1. As prey increases, predator will increase in

response2. As predators increase, prey will decrease3. As prey decrease, predators will decrease

POPULATION TASK

1) What are the effects of an overpopulation of deer? Why is it a problem?

2) What are some natural ways to control the deer population

3) What are some ways that humans can help control the deer population?

Human Population and Impact

NC SCOS 5.03

Objectives

• We can analyze the growth patterns of the human population

• We can explain the impacts of deforestation, pollution, and resource overuse on the environment

• We can inform the public about the dangers of human impacts and how to avoid resource overuse

Human Population

• Human population is currently about 6.8 billion– Human population growth has been exponential

Population Pyramid Graphs

• Developing countries tend to have high growth rates, whereas developed countries tend to have stable growth.– Population age distribution• Larger at the bottom = more future growth• Equal at each age = stable growth or even decline

• Population age distribution• Larger at the bottom = more future growth• Equal at each age = stable growth or even decline

Overpopulation: The Bad

• The problems with overpopulation include abuse of resources:– Deforestation– Fossil Fuel Overuse– Freshwater Overuse– Pollution– Lack of adequate food– Non-native species

Deforestation

• Cutting down forests leads to a loss of biodiversity: not as many different species in an area– Can affect local food webs, other species, and

even medicine!

Fossil Fuel Overuse

Burning Fossil Fuels

Excess CO2 in the air, traps heat

Greenhouse effect enhanced

Global warming

Freshwater Overuse

• Poor water quality, not enough freshwater in areas of need

• Polluted runoff from factories

Pollution

• Acid rain:– Sulfur and nitrogen gases released from factories

into the air – Sulfur dioxide: SO2

– Falls in rain drops, slowly impacts pH of water, soil, etc.

Pollution

• Ozone Layer Destruction– CFCs: chlorofluorocarbons – released into the air

through old refrigerator and spray cans, destroy ozone layer.

– Low ozone leads to high UV radiation– UV radiation: can cause skin cancer through

mutation

Why you should wear sunblock!

Food

• Lack of food sources• Most important in poor, developing countries

Introducing Non-native species

• Putting species into new ecosystems that aren’t supposed to be there– The introduced species generally outcompete, or

do better, than the native species. – Example: pythons in the everglades.

What Can We Do?

• Use renewable resources for energy– Water, wind, solar, and geothermal energy

What Can We Do?

• Reduce carbon dioxide emissions• Reduce water waste• Investigate factories and their pollution levels• Increase public awareness of the issues

What Can We Do?

• Promote sustainable practices– Using renewable energy, rotating crops, avoiding

pesticides and toxins, making sure we keep fishing populations high, conserve resources

Bioaccumulation

NC SCOS 5.03, 5.02b

Quick Vocabulary

• Autotroph: makes its own energy, a producer• Heterotroph: gets its energy from somewhere

else, a consumer

Quick Vocabulary

• Accumulate: to gain over time

Bioaccumulation

• Bioaccumulation: the buildup of toxins in top consumers after eating many smaller organisms in a food web – Also called biomagnification or bioamplification

Bioaccumulation• Imagine that a toxin, a pesticide, was sprayed

on the grass in the food web below. It cannot be released by the plant and is always stored.

http://www.ruralni.gov.uk/print/index/publications/press_articles/beef_and_sheep/archive-10/grass-attack.htm

Bioacummulation• Each level of organisms above the grass in the

food web will accumulate more and more of the toxin because they eat so much of the level below them

• For example, the mouse eats a large amount of grass, and stores all of the toxins in its body. Then the snake eats many mice, storing all of their toxins. Finally the hawk eats many snakes and stores all of their toxins in its body

Bioaccumulation

Eats 1,000 grasses = .001g

Eats 100 mice = .1g

Eats 10 snakes= 1g

1 grass has 0.000001g

Bioaccumulation

More toxin, concentrated

Even more toxin

Highest toxin levels

Lots of toxin, spread out

Why is biomagnification a problem?• What do you think?– Depends on the type of toxin– If the toxin is toxic, it might cause problems with

the functions of an organism• Impairs reproduction• Kills off members of a species• Prevents organisms from reproducing

What happens to the food web?• What do you think?– Decreased top consumers means more low level

consumers– More low level consumers means increased

amounts of the toxic toxin!– The top level consumers don’t stand a chance!

• Are we top level consumers? Can this happen to us?