Ecosystems Unit

Unit Essential Question: How are the living and nonliving things connected in an ecosystem?

Key Learning: All living and nonliving things on our planet are connected.

Concept: What’s In An Ecosystem?

Lesson Essential Questions:

1. How are population sizes determined? 2. How do you identify what is in an ecosystem?

 Vocabulary

Population

Sampling

Abiotic Factor

Biotic Factor

You will be able to answer these questions by the end this section

You should already know what these words mean. You will be able to use them in your responses and discussions throughout the unit

Ecosystems Unit

Ecosystems Unit

Investigation #1: Sampling Populations

Natural Selection is a species’ response to Environmental

Stress.

Environmental Stress is any factor in the environment that makes it harder for a species to reproduce or get what it needs to survive.

• Competition from an organism requiring a similar habitat.

• Climate change

• Predation

• Other factors that would put long term stress on a species!

• Change in availability or type of food

Environmental Stress could be…

Three basic things can happen when a species is under stress:

1. Go extinct in that area.2. Move to another area (emigrate).3. Adapt to survive the stress.

Ecosystems UnitWhat the Beak?

Part AComplete the reading in your packet and

answer the questions when you finish.

Ecosystems UnitWhat the Beak?

Part BYou will complete the lab. Follow all of Mr.

Herlihy’s instructions and do not move ahead. If you miss a step, you will have

skewed data and will not get full credit on the lab.

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Ecosystems UnitStructure/Function Lab

Among

OrganismsThere are three main types :

CompetitionPredation Symbiosis

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Competition:

Species that occupy similar niches will have to compete for these limited resources.

Food (nutrients), water and space are usually limiting factors in a habitat.

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Organisms have developed specialized forms, characteristics and behaviors that allow them to compete, these are called adaptations.

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Predation: An interaction in which one

organism kills and eats another!

The organism that does the killing is the predator,

the one that is eaten is the prey!

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PredatorsHave a wide range of specialized adaptations that allow them to catch prey.

Think of some predators that you know, what adaptations do they have that help them in their niche?

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PreyHave specialized adaptations to allow them to survive!

Such as:Camouflage- coloring or body parts that allow them to blend with surroundingsMimicry- body markings that make it look like something more dangerousProtective coverings- shell or spines that make them hard to catch or eatWarning colors- bright colors that warn predators that they are poisonous

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Symbiosis - a relationship between populations in which one or both populations is benefited.

There are 3 main types of symbiotic relationships:

commensalismmutualism

parasitism

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Commensalism- a relationship in which one species is benefited and the other is neither benefited nor harmed

For instance: barnacles on an oysterThe barnacle gets a place to live, the oyster is not harmed or helped.

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Mutualism - both species are helped.

For instance: oxpecker (also called “tick-pickers”) and herding animals such as cows or water buffalo. The “tick-picker” gets food and protection from predators. The herd animal gets relief from parasites.

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Parasitism- one species is helped, the other is harmed.

For instance: A tick and a dog. The tick gets food, blood from the dog. The dog is harmed, with too many ticks the dog will become anemic and will not be as healthy.Parasites RARELY kill the host. They almost always weaken it though.

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Energy Flow Through an Ecosystem

Food Chains, Food Webs, Energy Pyramids

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•Begins with the SUN•Photosynthesis

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

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Organisms that can make glucose during

photosynthesis are called PRODUCERS.

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Producers use most of the energy they make for themselves.

The energy that is not used by producers can be passed on to

organisms that cannot make their own energy. Organisms that cannot make their own energy are called

CONSUMERS.

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Consumers that eat producers to get energy:

• Are first order or primary consumers

• Are herbivores (plant-eaters)

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Most of the energy the primary consumer gets from the producer is

used by the consumer.

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Some of the energy moves into the atmosphere as heat.

Some energy in the primary consumer is not lost to the atmosphere or

used by the consumer itself.

This energy is passed on to another consumer.

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A consumer that eats another consumer for energy:

• Is called a secondary or second order consumer

• May be a carnivore or a herbivore

• May be a predator

• May be a scavenger

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Most of the energy the secondary consumer gets from the primary

consumer is used by the secondary consumer.

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Some of the energy is lost as heat, but some energy

is stored and can be passed on to another

consumer.

A consumer that eats a consumer that already ate a consumer:

• Is called a third order or tertiary consumer

• May be a carnivore or a herbivore

• May be a predator• May be a

scavenger

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Consumers that eat producers & other

consumers• Are called

omnivores

• Omnivores eat plants and animals

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The transfer of energy from sun to producer to primary consumer to secondary consumer to tertiary consumer can be shown in a

FOOD CHAIN.

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Sun

field mouse

owl

corn flower

toad

butterflyrabbit

grass

fungi moldbacteria

red fox rat snake

Decomposers break down all dead organisms and wastes from entire food web

Food Web

Another way of showing the transfer of energy in an ecosystem is the

ENERGY PYRAMID. Energy pyramids show:

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• That the amount of available energy decreases down the food chain

• It takes a large number of producers to support a small number of primary consumers

• It takes a large number of primary consumers to support a small number of secondary consumers

Ecosystems Unit

ECOLOGICAL PYRAMIDS: The concept of a pyramid is useful to describe the energy (trophic) levels of organisms, the amount of biomass (the mass of all the living material), and amount of energy transferred from one trophic level to another.

Producers

Primary Consumers

Secondary Consumers

Tertiary Consumers

Trophic Levels

Producer level has the largest amount of biomass

Primary Consumer level has 10% of the biomass found in the producer level

Secondary Consumer has 10% of the biomass found in the primary consumer level, that’s 1 % of the producer level

Tertiary Consumer has 10% of the biomass found in the

secondary consumer level, that’s 0.1 % of the producer

level

90% of the materials (biomass) taken in by consumers ends up as waste. This means that in order to make 1 gram of tertiary consumer biomass, 1000 grams of producer is needed in the beginning!

Biomass Pyramid

100% of the energy originally taken in by the plants

10% of the energy originally taken in by the plants

1% of the energy originally taken in by the plants

0.1% of the energy originally taken in by the plants

Energy Pyramid