1. IV. Ecology Definitions Symbiotic Relationships Biogeochemical Cycling
Ecological Succession
Georgia’s barrier islands: An example of ecosystem dynamics

2. A. Definitions
Ecology
The study of the interaction of populations of living organisms with other populations and with the environment
Population
A group of individuals, all of the same species
Community
A group of different populations
Physical factors in the environment
Oxygen concentration, salinity, temperature, rainfall, etc.

3. B. Symbiotic relationships
Symbiosis
A relationship between two species
Usually involves close physical contact
The major types are mutualism, commensalism, parasitism, and predator-prey relationships

4. B. Symbiotic Relationships
Mutualism
A symbiotic relationship between two species
In which both species benefit
Example:
Microbes in the stomach of cattle are responsible for the digestion of cellulose (fiber in grass & hay)
The cattle benefit because they use the glucose from the cellulose digestion
The microbes benefit because they get a warm, moist, protected place to live

5. B. Symbiotic Relationships
Commensalism
A symbiotic relationship between two species
In which one species benefits, and the other species is neither helped nor harmed
Example:
Small worms living attached to the shells of loggerhead sea turtles
The worms benefit because they get to travel through nutrient-rich waters as the sea turtle swims around (worms attached to the docks are stuck there)
There is no direct benefit to the turtle having worms stuck on its back, nor does there seem to be any harm done

6. B. Symbiotic Relationships
Parasitism
A symbiotic relationship between two species
In which one species benefits, and the other species is harmed
The species that benefits is called a parasite, and is typically much smaller than the other species (the host)
Example:
Pathogenic microorganisms that cause disease in humans, animals, and plants

7. B. Symbiotic Relationships
Predator-prey relationship
A symbiotic relationship between two species
In which one species captures & kills the other species for food
The species are generally about equal in size
The term is usually applied to animal species (or certain types of protozoan species)
Example:
Lions and wildebeests, cougars and rabbits, etc.

8. C. Biogeochemical cycling
Definition
The carbon cycle
The nitrogen cycle

9. Carbon Cycle

10. Nitrogen Cycle

11. D. Ecological Succession
Definition
A series of changes in the ecological community that inhabits an area or region
Occurs because the activities of living organisms (and nonbiological physical factors) change the conditions of a region (for example, soil chemistry) so that the region becomes more conducive to a different group of organisms

12. Bare Rock Succession
An example of primary succession: Succession beginning in an area or surface on which there has never been life before

13. Old Field Succession
An example of secondary succession: Succession that occurs in a region in which life has existed before, but in which the previous community structure has been disrupted
Frequently seen in North Georgia where cultivated fields (e.g. old cotton or soybean fields) are abandoned and no longer cultivated

14. Old Field Succession

15. D. Ecological Succession
Beach succession: Another example of secondary succession
The normal flora of humans: A medical example

16. E. Georgia’s Barrier Islands
Formation of the barrier islands
Beach building and erosion processes
Beach  dune  shrub zone  maritime forest succession
Salt marsh / estuarine ecosystems
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