Ecology Notes(1)



Interactions Between Organisms and their Environments Mr. Broderick NC SCOS Goal 5

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

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

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


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


• 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 • •


: use light to make their own energy


: eat other organisms to obtain energy •


: break down dead organisms for energy

Word Parts!

• Placing an “a” before a word makes it an




– Abiotic (not biotic; not living) – Atypical (not typical) – Anonymous (no name)

• • • • • • • • •


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


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 = abiotic The soil is made of rocks and minerals = abiotic A bird lays eggs = biotic Bacteria break down dead organisms = biotic The pH or the water is 2 (acidic) = abiotic


Abiotic or Biotic?

Abiotic Biotic Biotic

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

A) The rain on an open field washes away soil B) A hawk hunts a mouse and swoops down into the forest for the kill C) A lake has very acidic water which causes many fish populations to die


D) A deer grazes in a field of grasses


Independent Work

• • • Read your scenario card Identify the abiotic and biotic factors in the scenario Now, find others with your letter and check your work.

Mini-Lesson: pH

• pH: the measurement of how acidic, basic, or neutral a solution is

Weakly Acidic Weakly Basic

1 ------------ 4 ----------- 7 ------------ 11 ------------- 14

Strong Acid Neutral Strong Base (very acidic) (very basic)

Guided Examples

• • • • • Vinegar – pH of 4 Baking Soda – pH of 8-9

Acidic Basic

Tap water – pH of about 7


1 M HCl (hydrochloric acid) – pH of about 1 1M NaOH – pH of about 14

Basic Acidic

Guided Examples

• Which is more acidic?

A) pH of 2 B) pH of 5 C) pH of 7 D) pH of 11 • Which is more basic?

A) pH of 2 B) pH of 5 C) pH of 7 D) pH of 11

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


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

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)


What do the arrows in the food chain below indicate?

A. Sunlight B. Energy flow C. Heat transfer D. Toxins

What is energy?

• The energy that is transferred in an ecosystem is


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

Other animals get energy from the fat and protein in other animals Some animals get glucose from plants Plants make glucose from light

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

Tertiary Consumer Secondary Consumer Producer Primary Consumer

How is energy stored and transferred in an ecosystem?

A. In light B. In oxygen and carbon dioxide C. In carbon compounds like glucose D. In the process of decomposition

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

A. Hawk B. Rabbit C. Mountain lion D. 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. Snake B. Deer C. Frog D. 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

Less Energy More Energy

Energy Pyramid Labels

Tertiary Consumers Secondary Consumers Primary Consumers Producers

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)

0.1% 1% 10% 100%

Energy Transfer (calories)

1 calorie 10 calories 100 calories 1,000 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 efficient B. Energy is captured as heat C. Energy transfer is inefficient D. 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: a toxin process that occurs in


and converts light, carbon dioxide, and water


glucose (sugar) and oxygen.

Carbon Dioxide Water Sunlight Glucose Oxygen

More Photosynthesis

a. Photosynthesis


from the air.

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



c. The light energy helps


together to make glucose.

CO 2 and H 2 O

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

Starch Fat (nuts) Glucose O 2 Light CO 2 H 2 O

How do consumers get energy?


of organic molecules – Consumers eat other organisms to obtain organic molecules, which are forms of



– Energy is stored in the


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 (CO 2 ) – 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 moves 1) Atmosphere: Carbon is in the form of CO 2

CO 2

Carbon Cycle

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

C 6 H 12 O 6

Carbon Cycle

3) Consumers: Eat organic molecules and release CO 2 into the atmosphere during


, or die and go into the soil

CO 2

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

Carbon Cycle Stations

• • • • • Start at one of the stations Make your way to each different station based on a correct path through the carbon cycle If you can go to two different places, choose between them and then go back Write all answers on your sheet!

After you are done, explain to your partner the “story” of the carbon cycle, and have them explain back to you!

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 CO 2

Global Warming

• •

Global Warming

The Earth has been warming on average.

Could be due to increased CO 2 emissions into the atmosphere, which enhances the greenhouse effect and traps extra heat.

Global Warming

Excess CO 2


Greenhouse Effect Global Warming

Relationships in an Ecosystem



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

Types of Symbiosis

• • • Mutualism: both organisms


relationship from their Commensalism: one organism


, and the other is


Parasitism: one organisms


, and the other is


Symbiosis Summary

Relationship Type Mutualism Commensalism Parasitism Species A + + + Species B + 0 -

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



B. It enters


cells and begins to reproduce C. 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



• 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 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

Birth Rate > Death Rate

A: Slow growth as a population begins to grow

Population Growth Graphs

Birth Rate > Death Rate

B: Exponential growth as population grows rapidly

Population Growth Graphs

Birth Rate > Death Rate

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

Population Growth Graphs

Birth Rate = Death Rate

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

Carrying Capacity

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

Population Growth Graphs

Reaching Limit of Resources Carrying Capacity Exponential Growth, no limiting resources

Carrying Capacity

• Populations are typically


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


. Birth Rate > Death Rate


• 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 Rate B. Birth Rate – Death Rate C. Birth Rate x Death Rate D. Birth Rate / Death Rate

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

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

A. Birth rate = Death rate B. Birth rate < Death rate C. Birth rate > Death rate D. Birth rate = 0

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

A. Birth rate = Death rate B. Birth rate < Death rate C. Birth rate > Death rate D. Birth rate = 0

Predator vs Prey


another and


populations can affect one 1. As prey increases, predator will increase in response 2. As predators increase, prey will decrease 3. As prey decrease, predators will decrease



• • • Deer control is a major issue in North Carolina We are going to work as small groups to figure out the problems concerning deer management We will also brainstorm solutions to the problem.


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


• • • 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


Population Pyramid Graphs

• Developing countries tend to have


growth rates, whereas developed countries tend to have



– 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


• Cutting down forests leads to a loss of


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 CO 2 heat in the air, traps Greenhouse effect enhanced Global warming

Freshwater Overuse

• • Poor water quality, not enough freshwater in areas of need Polluted runoff from factories


Acid rain:

– Sulfur and nitrogen gases released from factories into the air – Sulfur dioxide: SO 2 – Falls in rain drops, slowly impacts pH of water, soil, etc.


Ozone Layer Destruction


chlorofluorocarbons – released into the air through old refrigerator and spray cans, destroy ozone layer.

Low ozone

leads to high UV radiation –

UV radiation:

mutation can cause skin cancer through

Why you should wear sunblock!


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

Introducing Non-native species

• Putting species into


ecosystems that aren’t supposed to be there – The introduced species generally


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

What Can We Do?

• Use


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


practices – Using renewable energy, rotating crops, avoiding pesticides and toxins, making sure we keep fishing populations high, conserve resources


NC SCOS 5.03, 5.02b

Quick Vocabulary

• •


: makes its own energy, a producer


: gets its energy from somewhere else, a consumer

Quick Vocabulary


: to gain over time


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


• Imagine that a


, a pesticide, was sprayed on the grass in the food web below. It cannot be released by the plant and is always




• • 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

Eats 10 snakes= 1g


Eats 100 mice = .1g

Eats 1,000 grasses = .001g

1 grass has 0.000001g


Highest toxin levels Even more toxin More toxin, concentrated 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?