Download 1.1_Populations_and_ecosystems

Populations and ecosystems
WAL:
about populations, ecosystems, communities, habitats & niches.
Some
Most
All
• How can a population be distinguished
from a community?
• What is meant by the terms “ecosystem”,
“population”, “community”, “habitat” and
“niche”?
• What is ecology?
Key words & definitions
Key word
Ecology
Biosphere
Biome
Ecosystem
Community
Populations
Individual
Niche
Biotic factors
Abiotic factors
Interspecific
competition
Intraspecific
competition
Definition
What is ecology?
• The word ecology comes
from the Greek for
“house”.
• Why do you think this is
appropriate?
The levels on which organisms can be studied
Biosphere
Biomes
Ecosystem
Community
Populations
Individual
go to FACTORS
Biosphere
• The volume of the earth’s surface where
organisms can be found.
• It extends from the depths of the ocean (11km
below sea level) to at least the highest plant
communities (6.2km)
Biome
• The biosphere is made up of several types of
biome.
• These are classified due to their major
vegetation types, for example TUNDRA or
TROPICAL RAINFOREST.
Ecosystem
• An Ecosystem is a part of a biome.
• Biomes themselves are far too large to study so
ecology work tends to be based around a
particular ecosystem.
• Each ecosystem has a characteristic set of plants,
animals and microbes.
• The organisms in an ecosystem form a selfsufficient unit in balance with their environment.
Community
• This is a group of species that occurs at the same
place at the same time.
• The word is often used to refer to organisms of a
particular kind, such as the plant community on a
lawn.
Population
• Ecosystems and communities contain
populations of species.
• A population is made up of all the members of a
species living together in the same place at the
same time.
• An example would be all the ash trees in a wood.
Individual
• Finally each population is made up of many
individuals.
• The genetic and physiological adaptations of an
individual organism to its environment is an
important aspect of ecology.
Look carefully at the information about
the 2 sea birds on the next slide...
The cormorant (Phalacrocorax carbo)
Structural
niche:
Broad cliff
ledges and the
sea.
Feeding niche:
a bottom feeder.
Eats mainly
flatfish, prawns etc
from shallow
water in estuaries
and harbours.
The shag (P. aristotelis)
Structural
niche:
Cliff ledges and
the sea.
Feeding niche:
Dives into the
water for fish.
What will happen here? How will these species affect each other?
The niche of a species is its role in the community.
Two species can’t occupy the same niche....
In reality the cormorant is quite
different to the shag:
• it occupies narrower ledges
• it fishes further out to sea
• it captures fish and eels from
the upper layers of the water
This means they are both able to be successful in the
same ecosystem
Competition
This happens when 2 or more individuals strive to obtain
the same resources when these are in short supply.
The more similar the individuals are, the more intense
the competition.
Competition
Competition can in intraspecific (between the
same species) or interspecific (between two or
more different species).
If an animal survives for a long time in a
particular community it must be able to
reproduce there.
A large number of biotic and abiotic factors
influence how an animal or plant species
may interact and change with time.
Biotic factors are any living factors
(e.g predators)
Abiotic factors are any non-living factors
(e.g sunlight).
Fire
temp
Solar
radiation
humidity
Wind
Day length
Atmospheric
gases
Aspect
organism
Soil
Human activity
Parent material
competitors
Salinity
Predators
parasites
Wave
action
Use a colour key to show BIOTIC and ABIOTIC factors.
BOLD arrows show the effect of the factors on the organism. Draw DOTTED arrows to show the
effect of factors on one another.
Learning check
1.
2.
3.
4.
5.
6.
7.
What is a habitat?
What is a niche?
What is a population?
What is a community?
What is an ecosystem?
What does an organism’s biotic environment consist of?
What is the difference between intraspecific and
interspecific competition?
8. Hyenas fighting over an animal carcass are engaging in
what type of competition?
Learning check
1. What is a habitat?
The place where a species is commonly found.
2. What is a niche?
The way a species exploits or makes a living from its
environment. This includes where it lives and where, when
and on what it feeds.
3. What is a population?
All the individuals of a particular species living in a particular
area.
4. What is a community?
All the populations of different species living and interacting
together in a particular area.
Learning check
5. What is an ecosystem?
A dynamic but more or less stable and self-perpetuating community of
organisms interacting with each other and with their non-living
surroundings.
6. What does an organism’s biotic environment consist of?
All the other organisms that it interacts with, from predators to
pathogens.
7. What is the difference between intraspecific and interspecific
competition?
Intraspecific competition is competition between individuals of the same
species. Interspecific competition is competition between individuals of
different species.
8. Hyenas fighting over an animal carcass are engaging in what type of
competition?
Intraspecific competition.
Constructing an ecosystem
• Within any ecosystem there are two main
processes to consider:
– The flow of energy through the ecosystem.
– The cycling of elements through the ecosystem.
• We are going to construct an ecosystem based
on these two main principles.
Lettuce
Hedgehog
Makes its own food using energy
from the sun.
Eats slugs and caterpillars.
Frog
Eats grasshoppers.
Eats lettuce.
Grass
Spider
Eats aphids.
Rabbit
Sparrowhawk
Eats lettuce and grass.
Eats voles and thrushes.
Makes its own food using energy
from the sun.
Aphid
Thrush
Vole
Eats grasshoppers.
Slug
Eats lettuce.
Eats grass.
Eats slugs and spiders.
Grass snake
Fox
Eats frogs.
Caterpillar
Eats hedgehogs, voles and
rabbits.
Grasshopper
Eats grass.
Constructing an ecosystem
• As well as the cards provided, you will also
have to draw/add your own elements to the
ecosystem as some are missing.
Constructing an ecosystem
• Cut out all of the cards and try to arrange
them in a logical ecosystem.
• Once your happy, glue them down.
• Draw arrows between organisms to show the
flow of energy (and therefore feeding
relationships) within the ecosystem.
• Around the outside, list any abiotic factors
which could affect the individuals in the
ecosystem.
An example ecosystem
And finally... Ecology Bingo
Draw a 2 x 3 grid and fill it with 6 of the key
words from today’s lesson...
Ecology
Biosphere
Biome
Ecosystem
Community
Individual
Niche
Biotic factors
Abiotic factors
Interspecific competition
Populations
Energy flow
Summary
Each species occupy an ecological niche
within their habitat. A group of one Species
forms a population. Populations of different
species form a community; these live in a
habitat. A group of habitats then make up an
ecosystem.