4TH GRADE SCIENCELAURA CARTER

Ecology

ECOSYSTEMS

The place an organism lives or spends most of its time is called its habitat.

Habitats can be small like under a rock or large like the ocean

Examples of habitats include: a tree, a pond, our backyards.

Can you think of an example of a habitat?

What makes up your habitat?

NAME THIS HABITAT.Name the two organisms in this habitat.What other organisms live in this habitat?A habitat provides organisms with everything they need to survive.

What do these two organisms need to survive?

SPECIES

Many different organisms live in a habitat.Each group of organisms is called a species.Organisms of each species can only reproduce with organisms of the same species.Examples of a species are: human beings, dogs, tulips, ladybird beetles, monarch butterflies, wood frogs, and bull frogs.

ALL THE ORGANISMS OF THE SAME SPECIES THAT LIVE IN A PARTICULAR HABITAT ARE CALLED A POPULATION.

For example, here are 3 populations in a pond habitat.

Duckweeds

FrogsWater snails

What is the size of each population found in this pond habitat?

COMMUNITY

All of the animals that live together in a habitat are called a community.

The community in a pond habitat is made up of all the populations of

different species of animals, plants, fungi, protists, bacteria, and archaea that

live in a habitat. Community = Population 1 + Population 2 + Population 3 + ….

COMMUNITY

For example, a pond community is made up of duckweeds, water snails, frogs and other populations.

How many populations of organisms can you see in this picture?

Ecosystem = Habitat + Community

The picture shows a pond ecosystem. It is made up of thehabitat (the place) and the community (all the different kinds of organisms in the habitat).How many kinds of organisms does this

ecosystem have?What is the

population of each?

ENVIRONMENT

The physical conditions of a habitat are called the environment.Physical conditions of a habitat include the temperature, amount of sunlight, amount and type of water, and type of soil.

Describe the environment shown in these pictures.

ECOSYSTEM

The community in a habitat, the environment of the habitat, and the

interactions among them make up an ecosystem.

DESCRIBE THIS ECOSYSTEM

What are the physical conditions? For example, is it hot,cold, wet, dry, sunny or shady?• What plants and animals live there and in which part of theecosystem do they live?• How are the organisms adapted to live in that ecosystem?

Describing Producers,

consumers, and decomposers in an ecosystem.

The sun is the main source of energy in most ecosystems.

Organisms that use light energy from the sun to make their own food are called producers like plants.

All other organisms in an ecosystem get their energy from producers.

Animals that get their energy by consuming other organisms are called

consumers. Animals are consumers in an

ecosystem.

DECOMPOSERSOrganisms that get their energy by decomposing, or breaking down, dead organic matter and waste are called decomposers. Nutrients contained in the decomposed organic matter return to the soil or air.Bacteria, fungi, and animals like worms and pill bugs are decomposers in an ecosystem.Bacteria and fungi are the most common decomposers.

Identifying producers and consumers in a

food chain

IDENTIFYING PRODUCERS AND CONSUMERS IN A FOOD CHAIN

Organisms get energy from the food they make or eat.

The transfer of energy from one organism to the next in an ecosystem is shown in a food chain.

The arrows in a food chain diagram show the direction in which energy is transferred.

The first organism in a food chain is a producer.

All other organisms in a food chain are consumers.

The first consumer in a food chain is the primary consumer. This consumer gets energy from the producer.

A secondary consumer is the second consumer in a food chain.

A secondary consumer gets its energy by consuming a primary consumer.

An organism that gets energy by consuming a secondary consumer is called a tertiary consumer.

A tertiary consumer is the third consumer in a food chain.

SAMPLE FOOD CHAINS

FOOD WEBS

Organisms can be members of more than one food chain.

In an ecosystem, all the food chains put together make up a food web.

Most organisms are part of more than one food chain because they eat and are eaten by more than one type of organism.

A animal that hunts and eats is called a predator.

The animals being hunted and eaten is called a prey.

When a snake eats a frog, the snake is the predator and the frog is the prey.

When a hawk eats a snake, the hawk is the predator and the snake is the prey.

What is an example of another predator/ prey relationship.

Food Web in a Forest Habitat

ENERGY PYRAMID The amount of energy being transferred in an

ecosystem is shown in a diagram called an energy pyramid

The first or bottom level of an energy pyramid contains producers.

The first level has the greatest number of organisms and the greatest amount of total energy.

The top level has the fewest number of organisms and the least amount of total energy.

The top level has the least energy because the organisms at lower levels use most of the energy that they produce or consume for living and reproducing.

Sun

Describe symbiotic relationships between

organisms

SYMBIOTIC RELATIONSHIP

In an ecosystem, organisms interact with organisms of different species.

An interaction between two organisms of different species that is beneficial, or helpful, to at least one of the organisms is called a symbiotic relationship.

MUTUALISM

A symbiotic relationship that is beneficial to both organisms is called mutualism.

An example of mutualism is the relationship between a bee and a flower. When a bee takes nectar from a flower for its food, pollen from the flower collects on the bees body. When the bee lands on another flower, the pollen is transferred to that flower and helps it reproduce. The relationship is mutually beneficial to both organisms and does not harm either.

MUTUALISM

Another example of mutualism is the relationship between a clownfish and a sea anemone.

The clownfish avoids predators by hiding among the sea anemone’s stinging tentacles, and the clownfish protects the sea anemone from the fish that eat it.

The oxpecker eats ticks off the impala’s coat

COMMENSALISM

When one organism benefits and the other is neither harmed nor helped, the symbiotic relationship is called commensalism.

Example: The relationship between birds called cattle egrets and herd animals, such as elephants. The cattle egrets follow herd animals and eat the insects stirred up by the animals. This is beneficial to the cattle egrets and neither helps nor harms the herd animals.

PARASITISM

If one organism benefits and the other organism is harmed, the symbiotic relationship is called parasitism.

Example: parasitism is the relationship between a dog and a tick. The tick is a parasite. The tick benefits because the dog’s blood is its food. The dog is harmed by loss of blood and also can be harmed by diseases the tick may carry.