1. Ecology and Population Dynamics

2. Ecological Organization
Levels of organization:
Organism- individual living thing
Population- group of the same species in one area
Community- group of different species in one area
Ecosystem- living (biotic) and nonliving (abiotic) factors in an environment
Biome- regional or global community of organisms

3. Biomes Tundra Taiga- coniferous forest (pine trees)
Deciduous forest- temperate climate
Rainforest
Desert
Grasslands
Freshwater
Marine- ocean (saltwater)
Estuary- mix of saltwater and freshwater

4. Energy Flow Producers (autotrophs)- make their own food
Consumers- get energy by eating other plants and/or animals
Heterotrophs
Carnivore- meat eater
Herbivore- eat plants
Omnivore- eat both plants and animals
Detritivore- eat detritus (dead organic matter)
Decomposer- break down dead organic matter

5. Food Chains Food chains show a sequence of feeding relationships
Trophic levels- levels in a food chain

6. Food Web Shows complex network of feeding relationships
One organism may have multiple feeding relationships and roles within the food web

7. Energy Pyramid Energy pyramids show energy flow among trophic levels
Only about 10% of energy is transferred from one trophic level to the next

8. Community Interactions
Competition
Two organisms fight for same resources
Predation
One organism captures and feeds on another organism

9. Symbiosis
Symbiosis- close ecological relationship between organisms of different species
Mutualism- both organisms benefit (ex: bat and saguaro cactus)
Commensalism- one organism benefits; the other neither benefits nor is harmed (ex: cattle egret and water buffalo)
Parasitism- one organism benefits; the other is harmed (ex: dog and flea)

10. Ecological Relationships+ -
Mutualism
Commensalism
Parasitism/Predation
Neutralism
Competition

11. Name the Relationship!
A certain kind of bacteria lives in the intestines of humans and many other animals. The human cannot digest all of the food that it eats. The bacteria eat the food that the human cannot digest and partially digest it, allowing the human to finish the job. The bacteria benefit by getting food, and the human benefits by being able to digest the food it eats.
Barnacles are sedentary crustaceans. Barnacles live by using long, feathering appendages to sweep the surrounding water for small, free-floating organisms. The critical resource for barnacles is a place to stay. Barnacles attach to rocks, ships, shells, whales, and just about anywhere else they can gain a foothold. Occasionally, barnacles will attach to the shell of a scallop. The barnacle gains a place to live and, presumably, the scallop is not harmed by the presence of the barnacles.

12. Name the Relationship!
Wolves are reintroduced into a habitat with a large coyote population. The wolves and coyotes both fight for the same food source.
Braconid wasps lay their eggs inside caterpillars. When the eggs hatch, wasp larvae eat their way out of the host caterpillar.
An owl population’s diet is made up mostly of field mice.

13. Population Dynamics Survivorship Curve
“K selected”- low birth rate, low infant mortality
“r selected”- high birth rate and mortality

14. Population Growth Patterns
Exponential growth
Unlimited resources

15. Population Growth Patterns
Logistic growth
Population levels off at carrying capacity (maximum number of individuals the environment can support)
Carrying capacity

16. Factors that Limit Population Growth
Density-dependent factors
Affected by the number of individuals in an area
Ex: competition, parasitism, predation, disease
Density-independent factors
Limit population growth regardless of population density
Ex: weather, natural disasters, human activities

17. Predator-Prey Interactions
Density-dependent
As hare population grows, so does lynx
Eventually the lynx eat too many hares and populations decrease again
Cyclic pattern

18. Ecological Succession
Succession: gradual regeneration or creation of a community
Primary vs. secondary succession

19. Primary Succession
Establishment of an ecosystem in a previously uninhabited area
Ex: new island formation after a volcano erupts
Pioneer species- first organisms that live in the are (often lichens and mosses)

20. Secondary Succession
Reestablishment of an ecosystem after a disturbance (such as fire)
Takes less time than primary succession
Climax community- stable, mature community