1. Ecology Notes – Part 1: Principles of Ecology

2. The multiple levels of biological systems
Ecology - The study of the interactions of organisms with one another and their physical environment

3. The multiple levels of biological systems
organism – an individual living thing ex) a black bat
population – all of the individuals of a species that live in the same area ex) the black bats

4. The multiple levels of biological systems
Community – a group of different species that live together in one area ex) the black bats, worms, moss, mushrooms, bacteria, and beetles living in the cave
Habitat – place where an organism usually lives ex) a cave is a habitat for a black bat

5. The multiple levels of biological systems
ecosystem – the different species (community) plus the environment (soil, water, weather); biotic factors + abiotic factors ex) soil in the bottom of the cave, light entering the cave, temperature in the cave, humidity in the cave, plus the community
biome – major regional or global community of organisms characterized by the climate conditions and the plant communities that thrive there

6. Vocabulary Quiz match the phrase to the correct word
community
ecosystem
population
organism
biome
habitat
fish, snails, & plants that live in a stream
a large group of zebras
tropical rainforest
rocks, water, mice, deer, oak trees
one mockingbird

7. Biotic & Abiotic Factors
biotic factors – are organisms in a habitat ex) animals, plants, fungi, protists, bacteria
abiotic factors – are the physical aspects of a habitat” ex) wind, water, rocks, sunlight, shade, etc.

8. What abiotic factors do you see here? What biotic factors do you see?

9. biodiversity is threatened by human activity
Ecosystems are complex. Changes to the biotic OR abiotic factors in an ecosystem affect all species.
biodiversity – the assortment or variety of living things in an ecosystem
biodiversity is threatened by human activity
pollution
global warming
habitat destruction

10. Biotic and Abiotic Factors
keystone species – a species that has an unusually large effect on its ecosystem
ex) sea otter – has a tremendous effect on the ecosystem it is a part of
sea otters eat sea urchins, which keeps the sea urchin
population under
control

11. Biotic and Abiotic Factors
keystone species continued
when the sea otter population is over-hunted, there are not enough otters to eat the sea urchins
the sea urchins, in turn, eat too much kelp (an aquatic plant, like seaweed) from kelp beds and the kelp population declines
without kelp beds, fish have no place to lay their eggs, so the fish population declines; when hunters stop hunting the sea otter population, the urchin populations decrease and the kelp beds and fish populations go back to normal

12. Food Chains and Food Webs
Producers provide energy for other organisms in an ecosystem
producer – organism that obtains energy from nonliving resources; organism that makes its own food
basis for ecosystem’s energy
most rely on sunlight
almost all producers obtain energy from sunlight
most producers use sunlight as their energy source
photosynthesis – 2-stage process that green plants and algae use to produce energy
6CO2 + 6H2O C6H12O O2
(SUNLIGHT)

13. Food Chains and Food Webs
autotroph – another word for producer; word parts: self feeder
consumer – organism that gets its energy by eating other living or once-living resources, such as plants and animals; connected to producers through energy, which ultimately comes from the sun
heterotroph – another word for consumer; word parts: different feeder

14. Food Chains and Food Webs
Label the organisms below as producer, autotroph, consumer, heterotroph (use all words that apply)
producer,
autotroph
consumer,
heterotroph
consumer,
heterotroph
producer,
autotroph

15. Types of Consumers
herbivores – organisms that eat only plants; ex) rabbit
carnivores – organisms that eat only animals; ex) snake
omnivores – organisms that eat both plants and animals; ex) chicken (eats seeds and insects)
detritivores – organisms that eat dead, organic matter; ex) millipede
decomposers – organisms that break down organic matter into simpler compounds; ex) fungi and bacteria
responsible for the last step in every food chain, returning nutrients to the environment
receive energy from every other level

16. A food chain is a model that shows a sequence of feeding relationships
***Energy FLOWS through ecosystems***
food chain – sequence that links species by their feeding relationships
note that the arrows that link one organism to another show the direction that energy is flowing; energy flows from the organism being eaten to the organism doing the eating

17. Draw the arrows to complete the food chain below:
Hawk

18. Trophic Levels
trophic levels – levels of nourishment in a food chain; ex) producer  herbivore  carnivore represents a food chain with 3 trophic levels
energy flows up the food chain from the lowest trophic level to the highest
producer – autotrophs – level 1
primary consumer (1̊ ) – herbivores & omnivores – level 2
secondary consumer ( 2̊ ) – carnivores & omnivore – level 3
tertiary consumer (3̊ ) – carnivores that eat carnivores, and some omnivores – level 4

19. Trophic Levels
tertiary
consumers
secondary
consumers
primary
consumers
producers

20. A food web shows a complex network of feeding relationships
food web – model that shows the complex network of feeding relationships and the flow of energy within and sometimes beyond an ecosystem
at each link, some energy is stored in the organism and some energy is dissipated (lost) to the environment
stability depends on the base – the producers (plants, algae, phytoplankton, some bacteria)

21. marine food webs show multiple trophic levels and food chains

22. Don’t forget about the online textbook resources like “Build a Food Web”

23. Pyramid Models
An energy pyramid shows the distribution of energy among trophic levels
energy in ecosystems comes from sunlight
energy flows UP the food chain from producer to consumer
some energy is lost from the ecosystem, mostly as heat
each level of a food chain contains less useful energy than the level below it

24. Pyramid Models
10%

25. Loss of Available Energy
biomass – measure of the total dry mass of organisms in a given area
incorporated into the body of a consumer
up to 90% of the energy stored in the eaten organism may be lost as heat (energy)

26. Energy Pyramids the longer a food chain, the more energy lost
energy pyramid – diagram that compares energy used by producers, primary consumers, and other trophic levels
illustrates how available energy is distributed among trophic levels in an ecosystem
energy is measured in kilocalories (kcal)

27. Label the correct amount of energy at each trophic level:? ? ?

28. End of Part 1