Title: The Ecosystem
1The Ecosystem
2Ecosystem
- A community of interdependent organisms and the
interactions with the physical environment in
which they live. - It can also be defined as the abiotic and biotic
factors and the interactions between them. - The interaction between organisms and the
environment is the key!
3Differentiate between the following terms
- Organism
- Species
- Population
- Community
- Niche
- Habitat
4In your notebook, draw a picture of a bunch of
little organisms
- Label The organisms of the same type (species)
- Circle individuals of the same species
(Population) - Draw interactions between the populations
(Community)
5Compare the terms habitat and niche
- Sometimes people confuse these terms.
- Figure out the differences between the terms.
6Niche vs habitat
- A habitat is wear an organism lives. The habitat
must provide a source of food, water and shelter
for the organism. - Niche The role of the organism. This is largely
to do with the trophic level of the organism. - For example plants produce food for the rest of
the food chain. Tigers keep herbivore
populations under control.
7Abiotic and Biotic factors
- Biotic Factor A living, biological factor that
may influence an organism or a system. - Example predation, disease, competition
- Abiotic factor A non-living, physical factor
that may influence an organism or a system - Examples Temperature, salinity, pH, light
8Which factors are biotic?
- Rabbits
- Cacti
- Daylight hours
- Precipitation
- Moss
- Soil composition
- Bacteria
9Limiting factors
- An abiotic factor can limit the population size
if there is too much or too little of it. Even
if there is the right amount of other factors - Examples to consider
- Sunlight
- Precipitation
- Salinity
- Nutrients in the soil
10Trophic levels
- Ecostems are often broken up and described
according to feeding relationships. - Trophic level
- The position of an organism in a food chain
- A group of organisms that occupy the same place
in a food chain
11Trophic levels in food chains
- Be able to give an example of each!
- Primary producers (autotrophs)
- Primary consumers (herbivores)
- Secondary consumers(carnivores)
- Tertiary consumers (top carnivores)
- Decomposers
- Detrivores
- Scavengers
12Energy flow and material cycling
13Producer lAutotroph - self feed lAn
organism that obtains organic food molecules
without eating other organisms but by using
energy from the sun or inorganic molecules to
make organic molecules lRemember This trophic
level supports all of the others lThe role of
producers is to convert energy into a form
useable for other organisms
14Producers
lMost producers are photosynthetic (e.g. algae,
mosses, diatoms, some bacteria, plants etc.) but
some are chemosynthetic (e.g. hydrothermal vent
bacteria) (H2)
15Decomposer
lAn organism that obtains energy by breaking
down dead organic matter, including dead plants,
dead animals and animal waste, into more simple
substances lExamples include bacteria and
fungi L Interconnects all trophic levels since
the organic material making up all living
organisms is eventually broken down lRole of
decomposers is to return valuable nutrients to
the system so they can be used again
16Compare detritus feeders to decomposers
17Consumer
lHeterotroph - other feed lAn organism that
obtains its nutrition by eating other
organisms lPrimary consumer (herbivore) - eats
producers e.g. sea urchin, copepod lSecondary
consumer (carnivore) - eats primary consumers
e.g. wolf eel, herring lTertiary consumer - eats
secondary consumers e.g. sea otter,
seal lQuaternary consumer - eats tertiary
consumers e.g. killer whale
18Consumers
- The role of the consumer is to transfer energy
from one trophic level to the next. - Notice that consumers have different names,
depending on what they eat - Herbivores plant eaters
- Carnivores meat eaters
- Omnivores eat plants and animals
19Food Chains
20Food webs
Show energy flow through an ecosystem L An
ecosystems trophic structure determines energy
flow and nutrient cycling
21Food webs
22Trophic levels
23Pyramid of biomass
24Second Law of Thermodynamics
- There is a tendency for numbers and quantities of
biomass and energy to decrease along food chains. - The pyramids become smaller at the top because
around 90 of the energy is lost between each
level and only 10 is available in the body of
the organism for transfer to the next level.
25Energy transfer in a food chain First law of
thermodynamics
26The end!