1. Natural Resources & Wildlife – Principles of Ecology
Introduction to Agriculture
AAEC – Paradise Valley
Spring 2015

2. What is Ecology?
Ecology: scientific study of interactions among organisms & their environment.
Reveals relationships between living and nonliving parts of the world
Ex. Shrimp rid ocean fish of parasites

3. Biosphere Portion of Earth that supports life (land, sea, & air).
Very diverse
Supports a large amount of different animals

4. Abiotic Factors Nonliving parts of an organisms environment.
Air currents, temperatures, moisture, light, soil
Often determines types of species which survives in an area
Ex. Lack of rain = drought = specific plant/area

5. Biotic Factors All the living organisms that inhabit an environment
Competition of the same/different species
Scientists investigate how biotic factors affect different species

6. Ecologists study interactions among organisms at several different levels.

7. Levels of Organization in Ecology
Organism
Populations
Communities
Ecosystems
Biosphere

8. Definition of Terms Organism: anything living
Populations: group of organisms of one species that interbreed & live in the same place at the same time.
May compete for food, water or other resources
How they share determines how far apart they live & how large the population becomes
Some have adaptations that reduce competition
Ex. Juveniles/adults different food requirements

9. Definition of Terms – cont.
Community: is a collection of interacting populations
Changes in one population will cause changes in another
Ex. Hawk and mice

10. Definition of Terms – cont.
Ecosystem: all the interactions between the biotic and abiotic factors in a certain place
Habitat: the place where an organism lives out its life
Niche: A role and position a species has in its environment
How it meets its needs for food and shelter, how it survives and how it reproduces

11. 3 Types of Ecosystems Aquatic 1.) Terrestrial  Land
2.) Marine  Salt Water
3.) Freshwater
Aquatic

12. Biomes
Biomes: A large group of Ecosystems that share the same type of climax community.

13. 6 Terrestrial Biomes Tundra Temperate Forest Tropical Rain Forest
Boreal (Coniferous Forest)
Grassland
Desert

14. 3 Aquatic Biomes 1.) Marine = salt water 2.) Freshwater = fresh
3.) Estuary = mixture of salt and fresh

15. Development of Ecosystems

16. Succession
The orderly, natural changes and species replacement that takes place in a community
Occurs in stage
Is often difficult to observe
May take decades

17. Primary Succession Colonization of new site
Takes a long period of time
Does not “first” contain soil
Ex. New Island

18. Secondary Succession Takes place after a natural disaster
Areas previously contained life and contains soil
Less time than primary
Ex. Fire, Flood, or Clear Cut

19. Terms to Know
Pioneer Species: the first plants to colonize an area

20. Terms to Know
Climax Community: a stable or mature community

21. 3 Types of Symbiotic Relationships
Symbiosis: close relationship between 2 or more organisms
Mutualism – both benefit
Ex. Shark & Cleaner Fish
Commensalism – one benefits the other is neither harmed or benefits
Ex. Sea Snail & Hermit Crab
Parasitism – One benefits and the other is harmed
Ex. Dog & Heart Worms

22. Terms to Know
Autotroph: an organism that collects energy from sunlight to produce food.
Heterotroph: an organism that gets its energy by consuming other organisms

23. Types of Heterotrophs Herbivore: a heterotroph that eats only plants
Ex. Cow, Rabbit, Grasshopper
Carnivore: a heterotroph that preys on other heterotrophs
Ex. Wolves, Lions
Omnivore: a heterotroph that eats both plants & animals
Ex. Bears, Humans
Detritivores: each fragments of dead matter in an ecosystem , return nutrients to the soil, air, and water where the nutrients can be reused by organisms
Ex. Worms, Aquatic Insects

24. Can you answer these questions?
What are producers?
What are consumers?
What are decomposers?

25. Trophic Level Each step in a food chain or food web is known as a trophic level.

26. Food Chain Simple Model How matter & energy move through ecosystems
Use arrows
No more than 5 links – energy decreasing
Energy lost as heat

28. Food Web More extensive model
How matter & energy move through ecosystem
Shows all the possible feeding relationships