1. Ecosystems
What is ecology?

2. Habitats
An organism obtains food, water, shelter , and other things it needs to live, grow, and reproduce from its environment.
Organism = an individual animal, plant, or single-celled life form (living thing)
Habitat = an environment that provides the things the organism needs to live, grow, and reproduce
Why do different organisms live in different habitats?

3. Biotic Factors
An organism interacts with both the living and nonliving parts of its habitat.
Biotic Factors = the living parts of a habitat
Name a biotic factor in your environment.

4. Abiotic Factors
Abiotic factors = the nonliving parts of an organism’s habitat
Examples: water, sunlight oxygen, temperature, and soil

5. Levels of Organization
Population = all the members of one species in a particular area
Species = a group of organisms that are physically similar and can mate with each other and produce fertile offspring.

6. Levels of Organization
Community = all the different populations that live together in an area
Ecosystems = the community of organisms that live in a particular area, along with their nonliving surroundings

7. Summary
The smallest level of organization is a single organism, which belongs to a population that includes other members of its species. The population belongs to a community of different species. The community and abiotic factors together form an ecosystem.

8. Energy Roles
An organism’s energy role is determined by how it obtains energy and how it interacts with other organisms. Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.

9. Energy Roles Producers = organisms that make their own food
Example: plants, algae and some bacteria
Energy enters most ecosystems as sunlight
Most producers use the sun’s energy to make food molecules (photosynthesis)

10. Energy Roles
Consumer = an organism that obtains energy by feeding on other organisms
Herbivores = consumers that eat only plants
Carnivores = consumers that eat only animals
Omnivores = consumers that eat both plants and animals
Scavenger = a carnivore that feeds on the bodies of dead organisms

11. Let’s Discuss What do herbivores and carnivores have in common?
What does an ecosystem need in order to allow matter to be recycled?

12. Energy Roles
Decomposers break down wastes and dead organisms and return the raw materials to the ecosystem.
Examples: mushrooms & bacteria

13. The movement of energy through an ecosystem
What is the difference between a food chain and a food web?

14. Example of Ecosystem

15. The movement of energy through an ecosystem
A food chain is a series of events in which one organism eats another and obtains energy.

16. The movement of energy through an ecosystem
A food web consists of the many overlapping food chains in an ecosystem.

17. Energy Pyramid
An energy pyramid shows the amount of energy that moves from one feeding level to another in a food web

18. Draw the pyramid
Decomposers

19. Another Way To Look At It

20. Biomass Pyramid
A biomass pyramid represents the total mass of living organic matter (biomass) at each trophic level in an ecosystem.

21. Density dependent factors = factors whose effects on the size or growth of the population vary with the size of the population.
Examples: availability of food, predation, disease, and migration
*The main factor is the availability of food.

22. Density-independent factor = Any factor limiting the size of a population whose effect is not dependent on the number of individuals in the population.
Example = earthquake, which will kill all members of the population regardless of whether the population is small or large.

23. Types of Interactions:
Species Interactions
Types of Interactions:
Predation
Competition
Symbiosis
Mutualism
Commensalism
Parasitism

24. Predation Predator-Prey
Predation is any interaction between two organisms in which one organism (the predator) consumes all or part of another organism (the prey).
Predator-Prey
Photo Credit: Dr. Kay Holekamp, MSU, (Image 13 from Photo Gallery)
Predation can involve one animal eating another animal.
Watch Video :
If still available, you can watch the entire episode from David Attenborough’s Life of Mammals, the Meat Eaters (50 minutes):

25. Herbivore-Plant Interactions
An herbivore grazing on a plant is another example of predation.
Photo Credit: Rhett A. mongabay.com
Herbivore-Plant Interaction: Manatee Grazing on Aquatic Plants

26. Prey Defenses
Predation usually results in the evolution of defensive adaptations in prey.
These can include:
Chemical defenses (toxins, poison, acrid sprays)
Behavior (living in groups, scouts, alarm calls)
Morphological features (spines, color, structures that allow you to run fast or detect predators), and other traits
Photo Credit: Rhett A. mongabay.com
Caterpillar with Venomous Spines

27. Behavioral Defense Example
Caterpillar Video:
A Different Twist on Predator-Prey Interactions
Watch “Battle at Kruger” taken by an amateur photographer on his lucky day:

28. Camouflage
Camouflage is protective coloration in which an animal resembles its background.
Photo Credit: Rhett A. mongabay.com

29. Competition
Competition in an interaction between two organisms that are using the same limited resource.
Competition can be within the same species (intraspecific) or between different species (interspecific).

30. Symbiosis
Symbiosis is an intimate relationship between different species in which at least one species depends upon the relationship to survive.

31. Types of Symbiosis
Mutualism: Both partners benefit from the relationship (+, +)
Commensalism: One partner benefits from the relationship; the other partner is not affected (+, 0)
Parasitism: One partner benefits from the relationship; the other partner is harmed (+, -)

32. Types of Symbiosis
When one partner is really small and lives inside of the other partner, the other partner is called the host.
The really small partner can be called a mutualist, a commensalist, or a parasite (depending on the type of relationship).
Sometimes, the really small partner is called the symbiont. This is a general term and does not imply a type of relationship.

33. Example of Mutualism Acacia ants live in acacia trees.
The tree provides big hollow thorns as a home for the ants.

34. Example of Mutualism
The tree also provides food for the ants in yellow swellings on the leaves (red oval).

35. Example of Mutualism
The ants defend the tree against herbivores, both large and small.
They attack insects and large grazing herbivores.

36. Example of Mutualism
The ants also clear an area around the tree of competing vegetation.
Without the ants, the acacia tree cannot compete with other trees.

37. Example of Commensalism
Cattle egrets are often found around grazing herbivores, such as these African buffalo or cattle in Texas fields.

38. Example of Commensalism
The cattle egrets eat insects that are flushed as the big herbivores move around.
The herbivores get no benefit or harm from the egrets.
Photo Credit: flickr.com

39. Example of Parasitism
Songbirds are often heavily parasitized by ticks.
The birds are often anemic, stressed and more vulnerable to predation.
Female ticks must have a good blood meal in order to lay eggs.
Photo Credit: Bill Hilton, hiltonpond.org

40. Example of Parasitism
Fungal parasites often infect living organisms, such as plants, animals or other fungi.
This shelf fungus releases enzymes to digest the wood of this tree, which weakens the tree and makes it more vulnerable.
Photo Credit: BIOL 1407 Student

41. Scholastic Jams: Symbiosis

42. CYCLES
Matter Cycles
Nitrogen:
Carbon Cycle:
Water Cycle:

43. WATER CYCLE

44. NITROGEN CYCLE

45. Carbon-Oxygen Cycle

46. The Food Cycle