Ecology LessonE. Haniff

Objectives• Understand the concepts of

ecosystem, habitat, producer, consumer.

• Explain these terms as well as the role of decomposers in the ecosystem

• Differentiate between abiotic and biotic factors

• Construct and interpret food chains and food webs

Objectives…• Relate feeding relationships to the

transfer of energy from the sun through plants to other organisms

• Evaluate the effects of removing any part of a food chain or food web

• Identify and explain the pyramids of numbers and biomass

• Identify specific feeding relationships

What is Ecology?

• Ecology is the study of the interactions between living organisms and their environment

Let us observe this pond….

What do we see?

• Living things…

• Non-living things…

Name the living things you see…

FrogSnakeBeetlesFishesDragonflyTadpolesLiliesWater plantsCat tails

We can classify these into two groups

Animals Frog Snake Beetles Fishes Dragonfly Tadpoles

Plants: Lilies Water plants Cat tails

What’s special about plants?...

Plants use the sun’s energy to PRODUCE food

So they are known as PRODUCERS

How are animals different from plants?

• Animals need to CONSUME (EAT) their food

• So they are known as CONSUMERS

Name the non-living things you see…

WaterRocksSoil

Can you name any other Non-living factors that affect organisms where they live?

• Sunlight• Wind• Temperature

Let’s go back to the definition of Ecology…

• Ecology is the study of the interactions between living organisms and their environment

• But what is the environment?

Environment

• The environment consists of the factors that influence how organisms live, grow and survive.

• The environment has two main components: the physical or abiotic factors and the living or biotic factors.

Environment

• So those living things we named form the biotic component

• And the non-living things form the abiotic component

EnvironmentBiotic Factors Abiotic Factors

Plants Temperature

Frogs Sunlight

Fishes Water

Beetles Dissolved gases (CO2, O2 )

Algae Salinity (salt content)

Snake Wind

pH (acidity or alkalinity)

Habitat• The habitat is the natural home of

an organism. • The area or place where an

organism lives, develops, grows, reproduces and hunts for food.

• It is not the same as the environment. The environment is the conditions that affect the organism while the habitat is the place the organism lives.

Case study…Scarlet Ibis

• The Ibis’ natural home is the Caroni Swamp

• So this is the HABITAT• But the environment would be eg:• The temperature, trees, crabs that

the Ibis eats• The environment affects how the

Ibis eats, grows, reproduces etc.

Can you name some Habitats?• Pond• River• Ocean• Forest• Desert• Grassland• Mangrove

Is it possible for another living thing to be a habitat?

Can you think of other examples?

OxenHumans

Activity….

Match the organisms to a suitable habitatSeashoreGrasslandOrganisms: zebra, barnacle, lion, grass, crab, mussel,

A little more about organisms

• Many organisms live in groups for reproduction, protection.

• A group of organisms of the same kind living in a habitat is called a POPULATION.

• For example in the pond there was a frog population

• But they were not the only group…

A little more about organisms

• Different populations of plants, animals and other organisms living together in a habitat make up a COMMUNITY.

Ecosystem

• An ECOSYSTEM is the interactions among different communities and their physical environment (the biotic and abiotic factors in an area).

• Eg. Seashore, mountains, rain forest, savannahs,

How do living things interact with each other?

How do non-living things affect the organisms?

How do non-living things affect the organisms?

• Consider this….• Can a fresh water fish live in the ocean?• The fish will not be able to tolerate the high

level of salt or salinity.• So an abiotic factor (salinity) has an effect on

the biotic factor (fish).

How do non-living factors affect other factors?

• Consider this….• The higher the temperature, the greater the

amount of rainfall available, so the wetter the environment

• The higher the temperature, the lesser the amount of gases dissolved in water, more difficult for organisms to breathe

Let’s go back to the pond…

What happens to all the dead organisms?

Decomposers

• Dead organic matter (plants and animals) are broken down by decomposers.

• The process of decomposition returns the living material to minerals and nutrients

• Which can then be reused by plants and animals

Understanding decomposition

• Photosynthesis is the process that converts inorganic material (carbon dioxide and water) into organic material (plant matter)

• Consumers eat plant matter and animals and build them into more complex structures

• Decomposers are organisms that break down decaying organic material back into inorganic matter.

Understanding decomposition

• They act by secreting digestive juices that chemically break down the organic matter

• Some is used for their growth and repair but some of the nutrients is returned to the ecosystem

• Some examples of decomposers are Fungi and earthworms.

• Some of the important elements that are cycled include Carbon, Hydrogen, Oxygen and Nitrogen.

Assessment activity

• Will a frog be able to live on the moon?• You were asked by NASA to design an

ecosystem that would allow frogs to live on the moon, write a brief description of the conditions needed (biotic and abiotic) to allow this.

• Distinguish among a habitat, an ecosystem and an environment

Thank you for your participationE. Haniff