Population, Community and Ecosystem

8/3/2019 Population, Community and Ecosystem

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Earth ±

Our Home



Mars ±

Lifelessplanet

Why are they different?



Ecology ± Study of interactionsbetween living organisms andtheir environment

CHAPTER FIFTEEN

Ecology



What is a Habitat???What is a Habitat???

Definition:Definition:A habitat is the natural homeof an organism where it lives

and reproduces.



Whose habitat is this?



Not all environment can be ahabitat.

An environment is best suited as the habitat of an organism if it:

offers ample supply of food

provides protection from predators

provides shelter from bad weather

allows organisms to reproduce, nest or hibernate



Name three habitats that can be found in a

school. Name the organisms that live in each of

these habitats.

Pond: water lettuce, water hyacinth, duckweeds, fish,

tadpoles.

Garden: trees, grass, butterflies, bees, birds, snails, ants.

Drain: algae, moss, ants, cockroaches.



freshwater

pond

populations

duckweed population

snail

population

dragonflypopulation

Definition:Definition:A population is made up of organisms of

the same kind in a particular habitat.

What is a

Population???

What is a

Population???

Examples:

People of different races living on Earth

The larvae, pupae

and butterflies in agarden



Definition:Definition:A community is made up of differentplant and animal populations livingtogether in a habitat.

What is a

Community???

What is a

Community???

freshwater

pond

community

Community = Population 1 + Population 2+ Population 3 + «

Examples:

Different populations of plants,

animals and microorganisms onEarth form a community.

Different populations of water

lettuces, pond skaters, fish and

other population form a

community.



Definition:Definition:An environment is everything surroundingan organism that affects how it lives.

Two parts make up the environment:1)Physical (Non-living)

2)Biotic (Living)

What is an

Environment???

What is an

Environment???



The environment is made up of:

Physical or abioticenvironment

Biotic environment

y Non-living environment such

as:

light

temperature

water

Oxygen

acidity or alkalinity (pH)

minerals

y Living environment

Herbivores

Carnivores

Onmivores

Scavengers



The EnvironmentThe Environment

Organisms that are best suited to their environmentsare most likely to survive and reproduce.Organisms that are best suited to their environmentsare most likely to survive and reproduce.

penguins adapt to cold

environments by having thicklayers of fat and feathers to

keep them warm

penguins adapt to cold

environments by having thicklayers of fat and feathers to

keep them warm

camels adapt to desert conditions by

having large flat feet for walking on

sand and deposits of body fat thatact as a food store

camels adapt to desert conditions by

having large flat feet for walking on

sand and deposits of body fat thatact as a food store

They adapt to theirenvironments by having

special body features orbehave in ways to help them survive.

They adapt to theirenvironments by having

special body features orbehave in ways to help them survive.



The Abiotic EnvironmentThe Abiotic Environment

LightLight

Plants need light to make food by photosynthesis.Animals need light to see so that they can moveabout, find food and avoid danger.

Plants need light to make food by photosynthesis.Animals need light to see so that they can moveabout, find food and avoid danger.

Some insects and deep-sea fish are able toproduce their own light tolook for prey or to attractmates.

Some animals, birds andinvertebrates avoid lightand are active in the dark.

bees need lightto find flowersbees need lightto find flowers

climbing ferns reach the

sunlight by entwining leaves

to climb up a support

climbing ferns reach the

sunlight by entwining leaves

to climb up a support



TemperatureTemperature

Temperature affects the growth, movement,activities and survival of the living organisms.

Most organisms can survive in temperaturesbetween 0°C and 45°C.

In temperate countries, mammals and birds migrateto warmer climates every year to avoid the cold

winters, whereas some animals hibernate.

Temperature affects the growth, movement,activities and survival of the living organisms.

Most organisms can survive in temperaturesbetween 0°C and 45°C.

In temperate countries, mammals and birds migrateto warmer climates every year to avoid the cold

winters, whereas some animals hibernate.



Can you tell which of these animals live in

cold regions?

8

Migratorybirds in flight



Some organisms have special features as a result

of temperature changes.

Examples: - Some plants shed leaves during winter

- Some animals have thick hair or

hibernate during winter.

Temperature also controls the process of

reproduction in plants as certain fruits and flowers

are seasonal.



WaterWater

All living things need water to survive.Water dissolves minerals so that plants can absorbthem.Water provides a habitat for fishes and otheraquatic living things.

All living things need water to survive.Water dissolves minerals so that plants can absorbthem.Water provides a habitat for fishes and otheraquatic living things.

cacti have thick stems to store water and a

strong skin which reduces loss of water; thesharp spines also protect them from predators

cacti have thick stems to store water and a

strong skin which reduces loss of water; thesharp spines also protect them from predators



OxygenOxygen

Most organisms need oxygen for respiration.Most organisms need oxygen for respiration.

guppies come up to the water surface to breathe oxygen

guppies come up to the water surface to breathe oxygen

roots of mangrove grow out of

the mud to breathe oxygen

roots of mangrove grow out of

the mud to breathe oxygen

Warm, polluted water contains lessdissolved oxygen than clean, cool water.

Some animals like guppy andgoldfish adapt themselves by coming to the surface of the waterto take in air when oxygen content

in the water is low.



Minerals are needed by plants for healthy growth.Plants obtain minerals from the soil in which they

grow.

Example: nitrates are used by plants to make

proteins.

MineralsMinerals



pHpH

The acidity or alkalinity of water and soil determines the

type of organisms that can live in it.

Freshwater organisms live in water with pH about 7 (neutral).

Marine organisms live in sea with pH about 8 (slightly alkaline ).



pHpH

Pineapples grow in acidic soil.

Environments that are too acidic or alkaline can kill

aquatic life in rivers and lakes and trees in forest.

Pineapples grow in acidic soil.

Environments that are too acidic or alkaline can kill

aquatic life in rivers and lakes and trees in forest.

pineapples and cotton plants

grow best in acidic soil

pineapples and cotton plants

grow best in acidic soil



The Biotic EnvironmentThe Biotic Environment

Living organisms never live alone.

Plants use the carbon dioxideproduced by animals duringrespiration for photosynthesis.Animals use the oxygen produced

by plants during photosynthesisfor respiration.

Organisms also depend on otherorganisms for food , shelter andprotection.

Living organisms never live alone.

Plants use the carbon dioxideproduced by animals duringrespiration for photosynthesis.Animals use the oxygen produced

by plants during photosynthesisfor respiration.

Organisms also depend on otherorganisms for food , shelter andprotection.



Herbivores

Carnivores

Omnivores

Scavengers



Herbivores are animals that feed on plants.

Example:

- grasshoppers feed on grass, butterflies feed on

nectar of flowers, caterpillars feed on leaves and

monkeys feed on fruits.



Carnivores are animals that feed on other animals.

Example: tigers, lions, eagles (NOTE: you cannottell whether an animal is a herbivore or carnivore

from its size)



Omnivores are animals that feed on both plants and

animals.

Examples: bears, raccoons, humans



Scavengers are organisms that feed on dead

organic matter.

Examples: vultures, hyena and crocodiles



Relationship between Organisms

Predator-prey relationship

Mutualism

Commensalism

Parasitism



Predator-Prey Relationship



Predator-Prey Relationship

Predators are animals that hunt other animals for food. The animal which is hunted are their prey

If a lion hunts a zebra for food, the lion is the predator and the

zebra is the prey. Predators usually have strong, sharp teeth and claws to hunt

and kill their prey.

Camouflage is a pattern or colouring that disguises an

organism or blends it with its surrounding so that it can hidefrom its predator.

Some organisms have secretions that are poisonous to

protect themselves from predators.





Further examples of how prey can

protect themselves from the predators



Mutualism



Mutualism

M

utualism is a relationship between two organismsin which both benefit.

Examples:

Clown fish and sea anemone.T

he sea anemoneprovides shelter and protection for the clownfish.

The clownfish brings food to the sea anemone and

even lures larger fish to its stinging tentacles.



Turtle

Commensalism



Commensalism

Commensalism is a relationship between two kindsof organisms in which one benefits while the other

neither benefits nor is harmed by it.

Example: Remora fish and shark. The remora fish

attaches itself to the shark and eats on food

scattered by the shark. The shark neither benefits

nor is harmed by it.



Parasitism



Parasitism

Parasitism is a type of relationship involving two

kinds of organisms, the parasite and the host.

The parasite benefits by living in or on the body

of the host, which in return is harmed.

Example: Ticks live on the body of dogs (host)

as parasites, feeding on their blood. The removal

of blood harms the dog.



EcosystemsAn ecosystemconsists of

communities of livingorganismsinteracting with oneanother and withtheir physicalenvironment.

The Earth is a big ecosystem known as the

biosphere.



Definition:Definition:

Ecosystem is the systemformed by plants and

animals interacting withone another and with thenon-living environment.

The study of ecosystem isa branch of science calledecology. A person whostudies ecology is calledan ecologist.

What is an

Ecosystem???

What is an

Ecosystem???

Ecosystem = Habitat + Community



Population A

Population BCommunity X

Population E

Population FCommunity Z

Population C

Population DCommunity Y

Ecosystem



Different EcosystemsDifferent Ecosystems

There are many ecosystems in the world:

deserts

grasslands

tropical rainforests

ponds

streams

rivers

oceans

mountains

seashores

There are many ecosystems in the world:

deserts

grasslands

tropical rainforests

ponds

streams

rivers

oceans

mountains

seashores



Different EcosystemsDifferent Ecosystems

Ecosystems canalso be man-made(artificial).If there issufficient lightand oxygen,organisms can

live for manyyears.

Ecosystems canalso be man-made(artificial).If there issufficient lightand oxygen,organisms can

live for manyyears.



Conserving the Environment



Effects of Man¶s activities on our

Ecosystem

1.Water pollution Release of untreated sewage

into the water

Seepage of pesticides and

fertilizers used in farming intothe water

Dumping of toxic chemicals

and radioactive waste into the

water Oil spills




Ecosystem

2. Land Pollution

Seepage of toxic chemicals and waste

into the water from rubbish buried in

dumping grounds called sanitarylandfills

Release of methane in landfills

Release of harmful substances into the

air when rubbish is burnt




Ecosystem

3. Air pollution Acid rain ± caused by release of sulfur

dioxide and oxides of nitrogen from

burning of fuels in industries and

vehicles. Thinning of ozone layer - caused by

release of chlorofluorocarbons (CFCs)

from aerosol cans, refrigerators, air-

conditioners and foam packaging.

Global warming- caused by the release

of greenhouse gases such as carbon

dioxide, methane, oxides of nitrogen.



What have you learnt?What have you learnt?

What does the term µhabitat¶ mean?

Name some common habitats.

What does the term community mean? Name the four types of relationships

between organisms.

What are the components of the abiotic( non-living) environment?

What can possibly happen to our

environment if we don¶t conserve it?

Documents

Population, Community and Ecosystem