OUR PLANETOUR PLANET

Unit 1-3aUnit 1-3a

Energy in the Energy in the EcosystemEcosystem

I Give Up. What’s black & white and read all over?

How Do Ecosystems Work?

The Sun - The source of all energy on Earth*

Without the sun, our planet would be cold and dark without anything to eat and fresh water

would be scarce!

Producers (Autotroph) – Make their own food; Ex: Plants Photosynthesis changes solar energy into chemical energy

Without producers there wouldn’t be any food for the…Consumers (Heterotrophs) – Obtain energy from other organisms; Ex: Animals, Fungi and many bacteria

Which are these?

Consumer Producers ???

Types of Consumers

There are four different types of consumers…

Why is a vegetarian still considered an omnivore?

Types ofConsumers

Energy Source

Examples

Herbivore producers cow, pleco

Carnivoreother

consumerssnake, vulture

Omnivoreproducers & consumers

people, bears

Decomposerdecaying matter

fungi & bacteria

Can Life Exist Without The Sun?

*Without the sun, life on earth could still exist due to…

Chemotrophs – These deep ocean bacteria get energy from hydrogen sulfide that’s released from volcanic vents

These bacteria supportentire ecosystems thathave never seen the sun!

Could life exist on Titan,one of Saturn’s moons, that’salmost 1 billion miles fromthe sun?

Maybe… It would need a volcanic coreto keep it’s ocean from freezing.

Storing & Using Energy

What does a plant need to survive?

Photosynthesis uses Water, Carbon Dioxide and Sunlight to create Sugar (energy stored as glucose) & Oxygen (waste)

H2O + CO2 + Energy C6H12O6 + O2

While plants use photosynthesis to create stored energy,

plants & animals have another process to use the energy…

Cellular Respiration – Plants and animals use Sugar andOxygen to get energy, releasing water & carbon dioxide

C6H12O6 + O2 H2O + CO2 + Energy

What do you notice about these equations?

Let’s Review…What have you learned in this unit?

1. Describe how energy from thesun can be used by a wolf.

2. Describe the four differenttypes of consumers.

3. How is matter from producersrecycled in the environment?

4. How could life exist on one ofSaturn’s moons?

5. Explain the similarities anddifferences between photosynthesisand cellular respiration.

OUR PLANETOUR PLANET

Unit 1-3bUnit 1-3b

Energy TransferEnergy Transfer

How Energy Flows

Trophic Level – Each step in which energy and matter are transferred within an ecosystem; Ex: Energy pyramid

Most of the energy taken in byan organism at one trophic levelis used before that energy canbe passed to the next level.

Organisms use their energyto complete life’s processes.

Which level has the highestpopulation? Which hasthe lowest population?

An Analogy for Trophic Levels • Think of our school

population in terms of size :

– Bottom = students – biggest population

– Above the students are the teachers

– Top of the pyramid is smallest population: Administration (Mr. Ross and the Vice Principals)

How Energy Flows

The 10% Law – Only 10% of the energy at each trophic level is passed on to the next and 90% is used or lost.

Carnivores are found at the top.And just ~50 Calories from thegrass are passed on to the lion.

Next are the herbivores.But only ~500 Calories arepassed on to the giraffes.

At the base of everypyramid are producers..

Make ~5,000 Calories of energy/m2 each year.

A Closer Look At Trophic Levels

Food Chain – A specific diagram that shows how energy flows from one organism to another

Why did the bald eagle populationdrop so much in the 1970s?

Thin eggs were being crushed bythe mom before they could hatch.

A look at the food chain showedthat DDT, a powerful pesticide,became more concentrated as itmoved up each trophic level.

In part, due to the damage caused by DDT, bald eagles were on the endangered species list from 1973-2007.

Seeing The Big Picture

Food Webs – Shows multiple, interconnected food chains;A more accurate image of howorganisms survive in an ecosystem

Each year, 1-3 million people arekilled by a deadly disease known as…

Malaria! It is transmitted, personto person, by the mosquito.

Wouldn’t it be great if we couldkill all the mosquitoes in the world?

How many other creatures wouldbe affected if mosquitoes vanished?

Where Did All Of These Come From?

Invasive Species – A foreign plant/animal that negatively affects an ecosystem; Species grow with few predators

•Compete with native species for resources

•Overpopulation

• Zebra Mussel – Carried by water from Russian boats. Each year they cause $500 million in damage to pipelines in our country.

• Asian Long-Horned Beetle –Arrived in wood from China,They burrow holes into manytypes of American treesultimately killing them;

Ecological Succession• Definition: Gradual process of change and replacement

of some or all of the species in a community • 2 types:

– Primary Succession: occurs on a surface where no ecosystem existed before

– Secondary Succession : occurs on a surface where an ecosystem existed before. • Disturbed or disrupted by humans or animals or

natural disasters. • Pioneer Species: first organisms to colonize a newly

available area. Usually lichen.

– When a community is stable it is called a climax community

Primary Ecological Succession

Secondary Ecological Succession

Let’s Review…What have you learned in this unit?

1. What is a trophic level?

2. Why does an energy pyramidtypically only have 4-5 levels?

3. Which types of organisms arefound at each level of an energypyramid?

4. Give an example of when studyinga food chain would be important.

5. Give an example of when studyinga food web would be important.

OUR PLANETOUR PLANET

Unit 1-3cUnit 1-3c

Species InteractionsSpecies Interactions

What’s A Niche?

Niche – A species role in the environment including… (Let’s use squirrels for example…)

• Its habitat

(Squirrels are common in forests and build nests in trees)

• Everything it needs to survive

(It eats nuts, bird eggs and other small organisms)

• Every interaction it has with other species

(It disperses nuts, limits other populations, its waste fertilizes the soil, & it is food for many predators)

Overlapping Niches

Squirrels are not the only species to live in trees,or eat nuts, or hoard for the winter so this

creates…

Direct Competition (-,-) – When species, or individuals, attempt to use the same limited resource

Sometimes species don’t even recognize their competition!

Indirect Competition (-,-) – Occurs even when the species may never come into direct contact

Ex: Owls are nocturnal…

Snakes are diurnal… So how do they compete?

Are there enough mice for both of them?

How Species Interact

There are four types of species interactions

Predation(+,-) – When a predator uses its prey as a source of food; Ex: Wolves and rabbits

Parasitism(+,-) – A parasite lives on or in a host without killing it immediately; Ex: Dog with ticks & heartworms

Why doesn’t the parasite want to quickly kill the host?

How Species Interact

Mutualism(+,+) – A relationship between two species in which both benefit; Ex: Acacia trees & ants, Humans and trees

What are the benefits for the tree and the ants?

Commensalism(+,0) – One organism benefits but the other isn’t helped or harmed; Ex: An orchid and trees

How does the orchid benefit by climbing the tree?

How Species Interact-A Giants Analogy!

Mutualism - Eli Manning throws a touchdown pass to Hakeem Nicks. Manning gets the completion and Nicks gets the touchdown for the team. (+ , +)

Commensalism - Giants have a bye week. The team benefits from the rest but no other teams are negatively affected. (+,0)

Predation/Parasitsm- Cory Webster closely follows his man Desean Jackson. When Vick throws the ball, Webster intercepts it. (+, -)

Competition - Two opposing receivers go up in the air for the ball and both get injured. ( - , -)

Who Is Who?

Mimicry – When two species have a similarity (in sound, scent, behavior, or appearance) that offers protection

• Milk Snake – Harmless but shares the same colors as the deadly coral snake; Red on black-Friend of Jack but Red on Yellow-Kill a Fellow… Can you tell which is which?

• Dead Leaf Mantis – What do you think this praying mantis is trying to mimic?

Can you see her?

Let’s Review…What have you learned in this unit?

1. How big is your niche?

2. What causes competition andwho benefits from it?

3. Compare & contrast parasite-host with predator-prey.

4. Describe the mutualisticrelationship between a termiteand the bacteria in its stomach.

5. Why are there so fewexamples of relationships thatare purely commensalism?