1. Environmental Science Mr. Vickers
Ecology
Environmental Science
Mr. Vickers

2. Ecology
The study of living organisms in the natural environment, how they interact with one another and how the interact with their nonliving environment

3. Levels of organization
atoms
species
molecules
population
organelles
cells
community
ECOLOGY
tissues
ecosystem
organs
systems
biosphere
organism

4. Species
A group of organisms that can reproduce and produce fully fertile offspring
Great White Pelican Pelecanus onocrotalus

5. Population
A group of organism of the same species which live in the same habitat at the same time where they can freely interbreed
Habitat: the environment in which a species normally lives or the location of a living organism
The black-veined white butterfly
(Aporia crataegi) mating

6. (Adephagia septempunctata)
Community
All the populations of the different species living and interacting in the same ecosystem
7-spotted lady bug
(Adephagia septempunctata)
Bean aphids
(Aphis fabae)
Red ant
(Myrmica rubra)
Broom plant
(Cytisus scoparius)

7. Ecosystem
Community (Biotic) interacting with environment (Abiotic )

8. Components of an Ecosystem
Biotic Factors: living or once living organisms
Abiotic Factors: nonliving factors that have an effect on living things
Examples:
- Water: organisms have water in their bodies (50-95%) and chemical reactions need water to happen.
- Soil: type of soil determines which plants and other organisms live in that location
- Light and Temperature: affect photosynthesis (plant growth is limited to amount of sunlight)
Energy + CO2 + H2O → C6H12O6 + O2

9. Energy and Organisms
Autotrophs: organisms which can synthesize their own complex, energy rich, organic molecules from simple inorganic molecules (e.g. green plants synthesis sugars from CO2 and H2O; bacteria in deep sea vents doing chemosynthesis) - PRODUCERS
Heterotrophs: organisms who must obtain complex, energy rich, organic compounds form the bodies of other organisms (dead or alive).
Ex: consumers and decomposers (saprotrophs and detritivores)

10. (Cantherellus cibarius)
Decomposers
Detritivores: heterotrophic organisms who ingest dead organic matter. (e.g. earthworms, woodlice, large scavengers). Ingest first, then digest.
Saprotrophs: heterotrophic organisms who secrete digestive enzymes onto dead organism matter and absorb the digested material. (e.g. fungi, bacteria). Digest first, then absorb.
Earthworm
(Lumbricus terrestris)
Chanterelle
(Cantherellus cibarius)

11. Consumers Omnivore: eats both plants and animals Carnivore: meat eater
Herbivore: plant eater

13. Food Chains Sequence of relationships between trophic levels.
Show the flow of energy from the SUN to the heterotrophs
Trophic level: an organism’s feeding position in a food chain
Producers: essential to every single food chain

14. Food Web
Shows the feeding relationships in a community. Arrows show the flow of energy.

15. Read the article and generate a food web: http://ehp. niehs. nih

17. How much is available to the caterpillar’s predator?
Growth (new biomass)
Cellular
respiration
Feces
100 J
33 J
67 J
200 J
Plant material
eaten by caterpillar

18. Energy and Nutrients
Energy enters ecosystems as light and usually leaves as heat.
Nutrients do not usually enter an ecosystem and must be RECYCLED. Nutrients include: carbon, nitrogen, phosphorus, magnesium...

19. The Carbon Cycle

20. The Nitrogen Cycle

21. Pyramids of Energy

22. Biomass Amount of dry matter in one organism
Each bar represents: dry weight of all organisms in one trophic level
Trophic level
Dry weight
(g/m2)
Tertiary consumers
Secondary consumers
Primary consumers
Primary producers
1.5 11 37
809

23. Populations Characteristics:
Size: number of individuals at a certain time
Density: number of individuals in a certain space at a particular time
Spacing: clumped, uniform, random
Age Structure
Pop. Change = (birth + immigration) – (death + emigration)
Limiting factor: prevents the continuing growth of a population in an ecosystem
Can be:
- water, air, light, food
- diseases, competitors, predators, parasites

24. Population Growth
Exponential Phase: population increases exponentially because the natality rate is higher than the mortality rate.
Transitional phase: difference between natality and mortality rates are not as great, but natality is still higher so population continues to grow, but at a slower rate.
Plateau phase: natality and mortality are equal so the population size stays constant.
Carrying Capacity: the maximum population size that can be supported by the environment

25. The Greenhouse Effect
Light from the sun has short wavelengths and can pass through most of the atmosphere.
This sunlight warms the earth which in turn emits long wave radiation.
This long wave radiation is bounced back by the greenhouse gases, such as carbon dioxide, methane, water vapor, oxides of nitrogen and sulphur dioxide

26. The Greenhouse Effect Natural and essential to life
Human pollution is making it worse = causing global warming
Oxides of nitrogen: industrial processes, burning fossil fuels, fertilizers
Methane: cattle, waste disposal, natural gas leaks
CO2: burning fossil fuels
Consequences:
Changes in climate = effects on the ecosystem
Extinction
Melting glaciers = rise in sea level
Increase in photosynthetic rates

27. Changes in atmospheric CO2

28. Precautionary Principle
Action should be taken to prevent harm even if there is not sufficient data to prove that the activity will have severe consequences
If people want to do activities that may cause a change in the environment they must prove first it won’t do harm
We should take action now: reduce carbon emissions before it’s too late
Should people invest money to reduce carbon emissions if we are not 100% sure about the consequences of global warming?
More expensive to be eco-friendly
What should consumers do?

29. Arctic Ecosystems North America, Greenland, Iceland, Norway, Russia
Example: polar bears/seals/algae affected
Loss of ice habitat
Increased success of pests/pathogens/mosquitoes
Increased decomposition
Expansion of temperate species/reduced range for arctic species
Rise in sea levels
Climate change
Disturbance of food chains
Melting of permafrost