Third Year Science
Ecology
In this topic:
• Ecosystems and Habitats
• Food chains
• Adaptation & competition
• Food web
• Interdependence
• Habitat study
• Conservation
• Pollution
• Waste management
What is Ecology?
Ecology: The study of the relationships
between animals, plants and their
environment
Ecosystem
Ecosystem: a group of interacting
organisms and their environment
Examples of ecosystems
Desert Coral reef Grassland Seashore
Habitat
Habitat: the area where an organism
lives
• Ecosystems are too big to study
• A small part of an ecosystem is usually studied
and this is a habitat
Habitat relationships
• Organisms in habitats interact with each other
• If one part is changed, it can affect others too
Examples of interactions
Shelter Food Support
Habitat feeding relationships
• Different organisms have different feeding
roles in habitats
• Each level is essential to maintain the overall
balance
Habitat feeding relationships
Producers: plants that make their own
food through photosynthesis
Examples of producers
Horse chestnut
Seaweeds Grasses
tree
Habitat feeding relationships
Consumers: animals that get their food
by eating plants or other animals
• Consumers can be split into 3 different groups:
– Herbivores
– Carnivores
– Omnivores
Habitat feeding relationships
Herbivore: an animal that only eats
plants
Herbivore examples:
Limpet Cow Bee
Habitat feeding relationships
Carnivore: an animal that only eats
other animals
Carnivore examples:
Ladybirds Heron Fox
Habitat feeding relationships
Omnivore: An animal that eats both
plants and animals
Omnivore examples:
Mussels Blackbird Badger
Habitat feeding relationships
Decomposers: Organisms that feed on
dead plants and animals
Decomposer examples:
Earthworms Fungi Woodlice
Food Chains
Food chain: a sequence of organisms where
each one is eaten by the next in the chain
• Way of showing energy and nutrient flow in a
habitat
Food chain example
Seaweed Limpet Oystercatcher
Food Chains
Food chain example
Seaweed Limpet Oystercatcher
Plant Herbivore Carnivore
Producer Consumer Consumer
Adaptation
Adaptation: a structure or habit that helps
an organism to survive in its habitat
Seashore Adaptations
Seaweed (Bladderwrack)
• Air bladders allow it to float in
the sea
• Allows it to get enough light
for photosynthesis
Seashore Adaptations
Limpets
• Attach strongly to rocks when
tide is in
• Can detach and feed when tide
is out
Mussels
• If attacked or disturbed, they
release their eggs into the
water so the next generation
can survive
Competition
Competition: when two or more organisms
require something that is in short supply
Examples of resources they may compete for:
• Space • Light
• Food • Water
• Water • Minerals
• Partners
Food Web
Food web: a number of interlinked food
chains
A food web in a grassland
Interdependence
Interdependence: living things depend on
each other for survival
Interdependence
Interdependence Reason
Animalsdependonplants Food,shelter,oxygen
Animalsdependon Food,protection(adults
animals protectyoung)
Plantsdependonanimals Pollination,seeddispersal
Plantsdependonplants Shelter,support
Plantsandanimalsdepend Releasechemicalsfrom
ondecomposers deadmaterial
Decomposersdependon Food
plantsandanimals
Habitat Study
Fieldwork: the study of a local habitat
Five steps of fieldwork
1. Draw a sketch map 2. Measure & record
or take a photo of the environmental
the habitat features
Five steps of fieldwork
3. Identify & list all 4. Photograph or collect
organisms in the organisms that can’t
habitat be identified
Five steps of fieldwork
5. Estimate the number of each
organism in the habitat
1. Mapping the habitat
• Draw a map or take a photo while in the field
• Draw a map from the photo afterwards
• Include:
– Walls
– Fences
– Pools
– Rocks
– Large trees
– Paths, etc.
2. Measuring environmental factors
Abiotic features: environmental (non-
living) features
• Need equipment like:
– Thermometer
– Light meter
– pH meter
3. Identify the organisms
• Use a simple key (remember these from 1st
year?)
• Use a picture guide
• Don’t damage or kill anything please!!!!
3. Identify the organisms
Key: a set of questions to help identify
an unknown object
• http://www.crickweb.co.uk/ks2science.html#
• Page 6 in your book
IDENTIFY
Methods for collecting organisms
• For fast moving organisms (e.g. beetles), we
need special equipment
Equipment Howit’sused Whatitcollects
POOTER
Sucksthe Insects,spiders,
organismintoajar smallanimals
SWEEPNET
Sweptoverlong Insects,caterpillars,
grass beetles
Methods for collecting organisms
Equipment Howit’sused Whatitcollects
BEATINGTRAY Placedunderbush
Insects,caterpillars,
orbranchwhichis
beetles,worms
shaken
PITFALLTRAP Placedinsoil, Crawlinganimals,
overnightif e.g.snails,slugs,
possible worms,woodlice
5. Estimating the number of each
organism in the habitat
• It would be impossible to count all organisms
in a habitat
• An estimate is taken based on random
samples
• Two methods are used:
1. Quadrat
2. Line transect
Quadrat
Quadrat: a square frame of known size
for estimating organism numbers
• Quadrat is placed randomly and organisms
inside the square are counted
• Repeated at least 10 times
Quadrat
Quadrat
Line Transect
Line transect: a string, rope or tape
that is marked at regular intervals
• Usually marked every 1 m
• Used for environments unsuitable for
quadrats
• Also used to estimate change over a changing
environment (e.g. getting closer to the tide)
Conservation
Conservation: the protection and wise
management of natural resources to prevent
organisms becoming extinct
• Need to protect habitats to protect the
organisms
• Important to look after all habitats and not
just those where ‘cute’ organisms live
Why is conservation important?
1. Prevent extinctions
2. Maintain balance of nature
3. For future generations
4. Preserve sources of medications
Pollution
Pollution: the addition of unwanted
materials to the environment
• Three main types of pollution:
Air pollution Water pollution Soil pollution
Waste Management
• What do we mean by ‘waste’?
• It includes:
– Dirty water
– Agricultural & industrial wastes
– Plastics & packaging
– Urine & faeces
Methods of waste management
Composting
Landfill Incineration
Waste management
Chapter 15:
Ecology
DONE!!
