1. Flow of Energy Through the Trophic Levels

2. WHAT IS ECOLOGY?
Ecology- the scientific study of interactions between organisms and their environments, focusing on energy transfer
Ecology is a science of relationships
What do you think about when I say ecology? Recycling? Acid rain?

3. The environment is made up of two factors:
Biotic factors- all living organisms inhabiting the Earth
Abiotic factors- nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents)
When I say environment you think what—weather. Well Ok but it it much more than that

4. Niche - the role a species plays in a community; its total way of life
The niche of the organism is the job the organism has in the environment. (Ex. Bees help plants reproduce by pollination.)
Habitat- the place in which an organism lives out its life
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
Habitat vs. Niche

5. A niche is determined by the tolerance limitations of an organism, or a limiting factor.
Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
Habitat vs. Niche

6. Habitat vs. Niche Examples of limiting factors - Amount of water
Amount of food
Temperature
Amount of space
Availability of mates
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

7. Feeding Relationships
There are 3 main types of feeding relationships
1. Producer - Consumer
2. Predator - Prey
3. Parasite - Host
How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?

8. Feeding Relationships
Producer- all autotrophs (plants), they trap energy from the sun
Bottom of the food chain
How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?

9. Feeding Relationships
Consumer- all heterotrophs: they ingest food containing the sun’s energy
Herbivores
Carnivores
Omnivores
Decomposers
Energy moves up the food chain through the producer/consumer relationship.

10. Feeding Relationships
CONSUMERS
Primary consumers
Eat plants
Herbivores
Secondary, tertiary … consumers
Prey animals
Carnivores
Herbivores are the 1st step up the food chain, they eat the producers

11. Feeding Relationships
Consumer-Carnivores-eat meat
Predators
Hunt prey
animals for food.
Scavengers are a type of carnivore that eat dead animals, or carrion. Vultures, hyenas, crabs, deep sea fish-talk about distance from the sun and must eat the dead things that sink to the bottom, bottom feeders

12. Feeding Relationships
Consumer- Carnivores- eat meat
Scavengers
Feed on dead
animals
Vultures are
scavengers
Scavengers are a type of carnivore that eat dead animals, or carrion. Vultures, hyenas, crabs, deep sea fish-talk about distance from the sun and must eat the dead things that sink to the bottom, bottom feeders

13. Feeding Relationships
Consumer- Omnivores -eat both plants
and animals
Humans and bears are omnivores but a large and important subset of omnivores are the decomposers. They breakdown dead producers and release the energy back into circulation.

14. Feeding Relationships
Consumer- Decomposers
Breakdown the complex compounds of dead and decaying plants and animals into simpler molecules that can be absorbed
Humans and bears are omnivores but a large and important subset of omnivores are the decomposers. They breakdown dead producers and release the energy back into circulation.

15. A trophic level is the position occupied by an organism in a food chain.
Each link in a food chain is known as a trophic level.
Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem.
Trophic Levels

16. Organisms that share a trophic level get their energy from the same source.
Producers are found at the base of the energy pyramid and comprise the first trophic level of the food chain.
Producers capture energy as sunlight and converts it into usable forms.
Trophic Levels

17. Above producers are the primary consumers that make up the second trophic level.
Above the primary consumers are the secondary consumers that occupy the third trophic level.
Finally, there are the tertiary consumers at the top trophic level.
This group is often called the “top” of the food chain.
They are generally omnivores, like humans, or carnivores, like lions.
Trophic Levels

18. E N R G Y Trophic Levels Producers- Autotrophs First Trophic Level
Tertiary consumers- top carnivores Fourth Tropic Level
Secondary consumers-small carnivores
Third Trophic Level
Primary consumers- Herbivores
Second Trophic Level
Producers- Autotrophs
First Trophic Level

19. It takes a large number of producers to support a small number of primary consumers
It takes a large number of primary consumers to support a small number of secondary consumers
Amount of available energy decreases for higher consumers or/energy decreases the farther you move from the primary producer.
Energy Pyramid

21. Some energy in the primary consumer is STORED & not lost to the atmosphere or used by the consumer itself.
What happens to all energy as it moves up the pyramid?
Some energy is used by that trophic level for metabolism, some of the energy is lost as heat, and some energy is stored and can passed on to the next trophic level (10%).
Energy Pyramid

23. The Ten Percent Law states that the amount of energy available to organisms at a particular trophic level is ten percent of what it was at the previous level.
Some of the energy is stored in tissue, some is used for metabolism, locomotion, reproduction and homeostasis.
10% Law

24. 10% Law

25. Trophic Levels
Food chain- simple model that shows how matter and energy move through an ecosystem

27. Food web- shows all possible feeding relationships in a community at each trophic level
Represents a network of interconnected food chains
Trophic Levels

29. Organic material produced in the ecosystem is referred to as Biomass.
Producers add biomass to an ecosystem by making organic molecules.
The stored biomass is what is passed on to other organisms in the ecosystem.
Energy is measured in kilocalories (kcal)
kcal – the heat required to raise the temperature of one kilogram of water by one degree
kcal represents 1000 true calories of energy
Measuring Biomass

30. Calculating Available Energy
Food Chain 1:
Phytoplankton – zooplankton – smelt – trout – humans
10,000 kcal – 1,000 kcal – 100 kcal – 10 kcal – 1 kcal
Food Chain 2:
Phytoplankton – smelt – humans
10,000 kcal – 1,000 kcal – 100 kcal
Which food chain gives the human more energy?
How much more energy?
Calculating Available Energy