1. Interactions Among Living Things

2. Environment & Ecology
Environment = all living (biotic) and nonliving (abiotic) that an organism reacts with.
An environment provides all resources needed to live and grow.
Living things that share an environment also affect one another.
All organisms of an environment are interconnected.
Ecology – study of the relationships of organisms and their environment.
Ecologists – the scientists who study ecology.

3. Biotic & Abiotic Biotic Abiotic Birds/Animals Tree/Grass Worm Bacteria
Insects
Abiotic
Soil
Sun

4. Levels in Environments
Ecologists organize the relationships of organisms into four levels:
Individual – A single member of a species.
Populations – a group of individuals from the same species living in a specific area at the same time.
Community – All the interacting populations of species in an environment.
Ecosystem – Made up of both the community of organisms in an area and their abiotic surroundings.

5. Forest Ecosystem
Community
Population
Individual

6. Habitat vs. Niche Habitats – The place in which an organism lives.
Provides everything an organism needs for its survival.
Populations of different specials avoid fighting over resources by using them in different ways.
Niche – The unique strategy a species has for survival, its occupation or job.
Two organisms may share a habitat but NOT a niche!
Death with occur to one of the organisms.

7. Feeding Levels What process does this best represent?
Producers – (autotrophs, “self-feeders”)
The source of all food in an ecosystem!
Use photosynthesis to make their own food
Green plants and certain microorganisms.
What process does this best represent?
What is the primary source of all
energy in an ecosystem?
Photosynthesis:
Energy + CO2+ H2O = O2 + Glucose
SUN

8. Feeding Levels Consumers Feed directly or indirectly on producers.
DO NOT have the ability to make their own food.
4 Types:
Herbivores – plant eaters ONLY
Ex. Rabbit, mouse, grasshopper
Carnivores – meat eaters
Ex. Eagle, lion, tiger
Omnivores – eat both plants and animals
Ex. People
Scavengers – eat dead organisms
Ex. Hyenas, vultures, crows

9. Feeding Levels Decomposers
Break down dead organisms into simpler substances (decay).
“Nature’s recyclers”
Ex. Mold, mushrooms, worms and bacteria

10. Producers
Herbivore
Carnivore
Omnivore
Decomposer
Trees
Squirrel
Robin
Worm
Grass
Blue Jay
Bacteria
Leaves
Woodpecker
Beetle

11. Food Chains and Webs The flow of energy through an ecosystem.
Direct link of one organism to another in a feeding pathway (trophic level).
Food Web
All feeding relationships within an ecosystem.

12. Energy Levels
The location of an organism in a feeding level crates energy levels:
How much energy is obtained by an organism from the food it consumes.
10% Rule – Only 10% of the energy a food resource has goes to the consumer.
Energy decreases!

13. Relationships Among Populations
Communities are made up of many populations that share the same resources.
Organisms within these communities coexist by having one of three different types of relationship:
Symbiosis
Competition
Predation

14. Symbiosis
A close relationship between individuals of two or more species.
Symbiosis = Greek
Syn = “together” and bios = “life”
Can occur in 3 ways:
One lives near the other.
One lives on the other.
One lives in the other.

15. Symbiosis Ex – bee & flower pollen.
Commensalism: one benefits and the other is unharmed.
Ex – Sea anemone & fish
Mutualism: Both benefit
Ex – bee & flower pollen.
Parasitism: One benefits, the
other is harmed.
Ex – tick on dog

16. Competition When two species struggle for the same limited resources.
Each is hurt by the presence of the other.
The ability to compete and win is one of the most important causes of evolution by natural selection.
fight over food, water, shelter or breeding rights.

17. Predation When one organism kills and eats another organism.
Involves two individuals:
Predators - organisms that catch, kill and eat other organisms.
Prey – those organisms being killed and eaten.
Importance:
Reduces size of prey population.
Maintains diversity of an ecosystem.

18. Predator/Prey Relationships
Who is the predator?
Who is the prey?
As the wolf population increases, what happens to the moose population, from ?
If another predator of the moose moved into this area, what do you think would happen to the wolf population?
What is this called?
Wolves
Moose
Decreases
Decrease – not enough food for both
Competition