Ecosystems Part 1. Organism Population Community Ecosystem An ecosystem includes all of the organisms as well as the nonliving things in a given area.

EcosystemsPart 1

OrganismOrganism

Population

Population

Community

Community

Ecosystem

Ecosystem

• An ecosystem includes all of the organisms as well as the nonliving things in a given area.

OrganismOrganism

Population

Population

Community

Community

• A community is a group of different species that live together in one area.

An ecosystem includes both biotic and abiotic factors.

anything that is LIVING is considered biotic. Examples: plants animals fungi Bacteria

plants

Abiotic factors are nonliving things.

– anything that is NON-LIVING is considered abiotic.Examples:– moisture– temperature– wind– sunlight – Soil– https://www.youtube.com/watch?v=E1pp_7-yTN4

moisture

sunlight

Carrying Capacity and Limiting Factors

Carrying Capacity What exactly is carrying capacity?

Carrying capacity refers to the number of individuals a certain habitat or area can support given the resources that are available

Carrying Capacity All animals need basic things to survive and

they must get these things from their habitat

Animals need Food Water Shelter Space

Carrying Capacity

No matter where you are on planet Earth, there will be some resources that are in short supply

For instance: In a desert water is very scarce and hard to

find In a rainforest space is limited In the mountains food might be hard to come

by

Carrying Capacity: Home Life Think about your home

Everyone might have their own bed, a place to put their clothes, enough food to eat and water to drink, as well as an area they can go to and relax

Carrying Capacity: Home Life Now imagine that 5 people moved in

What would happen?

What would happen if 10 people moved in?

How about 30 people?

Carrying Capacity:Home Life Just like in nature, your home has a carrying

capacity: a certain number of individuals that can live there and still find everything they need

Once you go above that number, life becomes very difficult!

All Habitats Havea Carrying Capacity

All places have a certain number of individuals that can live there and still gain everything they need

Once the number of individuals pass that number, life gets harder and harder

Ecosystems

Limiting Factors

Let’s suppose…. We have two mice…:

and they produce the standard 56 “pups” (baby mice) each year.and each of these mice goes on to have 56 babies each year….

Soon…..

We’d be over-run with mice on the planet!!

Why doesn’t this occur?

Limiting Factors

A limiting factor is an abiotic or biotic factor that limits the number of individuals in a population.

Limiting Factors

Limiting factors can include:

1. Space2. Food3. Water4. Disasters: fire, flood,

drought, disease

SPACE

Human activities play a large role

Development, damming rivers, clear cutting forests.

Predators: Food As the prey

population increases, the predator population increases. As the prey population decreases, then so does the predator population.

Example: Lynx and Hare:

Disaster: Drought If a drought comes

along, the water supply goes down.

The number of animals living in or near the water would decrease because there would not be enough water to support a larger number of animals.

https://www.youtube.com/watch?v=8FPMP41LYJ8

Part 2: Producers and Consumers

ProducerMakes food by changing light energy of

the sun into chemical energy, or foodAlso called AutotrophsEx. Plants, algae, some bacteria

ConsumersOrganisms that do not make their

own food

Also known as HETEROTROPHS

Ex. Rabbits, Deer, Mushrooms

HeterotrophsConsumers

A. Herbivores – eat ONLY plants Ex. – Cows, Elephants, Giraffes

HeterotrophsConsumers

B. Omnivores – eat BOTH plants and animals Ex. – Bears and Humans

HeterotrophsConsumers

C. Carnivores – eat ONLY other animals Ex. – Lions, Tigers, Hawks

https://www.youtube.com/watch?v=O_4HozC8qww

HeterotrophsConsumers

D. Scavengers/Detritivores – feed on the tissue of dead organisms (both plants and animals) Ex. – Vultures, Crows, and Shrimp

HeterotrophsConsumers

E. Decomposers – absorb any dead material and break it down into simple nutrients or fertilizers Ex. – Bacteria and Mushrooms

Part 3: Food Chains https://www.youtube.com/watch?v=Cd1

M9xD482s

Food Chain

Food ChainsThe energy flow from one trophic level to the

other is know as a food chain.1.The SUN begins ALL food chains.2.Next, are the PLANTS, AKA Primary

Producers3.After producers are PRIMARY CONSUMERS4.Then, SECONDARY CONSUMERS5.Next, the TERTIARY CONSUMERSSome food chains will go to another level, but

most don’t go beyond four levels.ALL food chains end with DECOMPOSERS.

Trophic LevelTrophic Level

Each step in a food chain is called a ___________. The trophic level indicates:the organism’s position in the sequence of energy transfers.

trophic level

The first trophic level in a food chain is always made up of _________. These organisms are referred to as _________________.producersprimary producers

The second trophic level is occupied by the __________ that feed on the _________. These organisms are referred to as _________________.herbivores producers

Primary consumers

Trophic Levels (feeding levels)

Primary Producers

(Autotrophs)

Primary consumers

(Herbivores)

Secondary Consumers(carnivores or omnivores)

____________________ belong to the third level. These organisms are referred to as:secondary consumers.

Most ecosystems contain only ____________ trophic levels.

Predators of herbivores

Each consumer depends on the:trophic level below it for energy.

three or four

Food webs

Trophic Levels: Primary Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer?

Grass Mouse Grasshopper Frog Owl Hawk

Trophic Level:

Producer, primary consumer, secondary consumer, tertiary consumer

Grass Producer

Mouse Primary consumer

Grasshopper Primary consumer

Frog Secondary consumer

Owl tertiary consumer

Hawk Secondary consumer

Part 4: Food Webs http://studyjams.scholastic.com/studyja

ms/jams/science/ecosystems/food-webs.htm

Food web

Food web: The network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.

A food web links all the food chains in an ecosystem together.

Food Webs

In an ecosystem, the feeding relationships between organisms are much too complex to be shown in a ….. ….. single food chain.

Many consumers eat:more than one type of

food. More than one species

may feed on:the same organism.

Many consumers eat:more than one type of

food. More than one species

may feed on:the same organism.

There are many complex interactions between many different food chains.

A QUICK REMINDER…

What is the primary source of energy for an ecosystem?

What do the plants do with the

glucose they produce?

What do the plants do with the

glucose they produce?

About ____ of the glucose is used immediately in _________________. Respiration is the conversion of:glucose into molecules of ATP, the energy source for a cell.

Some of the glucose molecules are used as raw materials (building blocks) for the building of other _______ compounds within the cell.Much of the glucose is…..…..stored by the plant for future use.

half

cellular respiration

organic

Part 5: Energy Pyramids

Energy Transfer Between Trophic Levels

The amount of energy or matter in an ecosystem can be represented by an:…..ecological pyramid.

Ecological pyramid: A diagram that shows the amount of energy contained within each trophic level in a food chain or a food web.

Roughly ____ of the total energy _________ in one trophic level is

passed to the organisms in the ________________.

10%consumed

next trophic level

The pyramid shape of the diagram to the right represents the low percentage of energy transfer from one trophic level to the next.

Ecological Pyramid

Why is the transfer of energy to the next trophic level so low?

Not all of the ______ possessed by the organisms at one trophic level will be _______ up to the next trophic level. Organisms ____ much of the energy they ________ for their own ___________ such as respiration, movement, or reproduction.

energypassed

use consume

Many organisms at one trophic level will _________________ by the _________ at the next level. The _______ of these “_______” will not be passed to the organisms at the _______ level.

escape being eatenpredators

energyescapees

higher

life processes

The following is a hypothetical food chain:

grass ---> grasshopper ---> toad ---> black snake

The grass occupies what trophic level? It is the producer.The grasshopper occupies what trophic level? The grasshopper is the primary consumer.

The toad occupies what trophic level? Secondary consumerThe black snake occupies what trophic level? Tertiary consumer

If the energy content of grass is approximately 5,000 calories per square meter of land surface, then the energy content of the black snakes should be approximately how many calories per square meter?Answer: About 5 calories per square meter.

The low rate of energy transfer between trophic levels explains why:food chains rarely contain more than a few trophic levels. Organisms occupying the lower trophic levels are usually much more _________ than organisms belonging to the highest level. There are many more grasses, shrubs, and trees than there are __________. There are many herbivores (deer, antelope, gazelles) for each ______________.

abundant

herbivores

carnivore (lion)

Higher trophic levels contain less ______, and

therefore, they can support fewer _________.

energy

individuals

Transfer of EnergyWhen a lion eats a zebra, it does

not get all of the energy from the zebra (much of it is lost as heat)

Only 10% of the energy from one trophic level is transferred to the next – this is called the 10% rule

https://www.youtube.com/watch?v=ScizkxMlEOM

Ecological Pyramid

• Which level has the most energy?• Which level has the most organisms?• Which level has the least organisms?• Which level has the least energy?

Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass. -- G. Tyler Miller, Jr., American Chemist (1971)