1. Ecosystems and Communities
Ecology
Ecosystems and Communities

2. Weather vs. Climate
Weather is the condition of the Earth’s atmosphere at a particular time and place.
Atmosphere is the Earth’s “insulating blanket”
Climate is the average yearly condition of temperature and precipitation in a region.

3. Climate is caused by:
Latitude
Winds and ocean currents which transport heat through the biosphere (unequal heating)
Shape and height
of landmasses

4. Greenhouse Effect
The temperature on Earth stays suitable for life due to the trapping of heat by gases in the atmosphere causing a natural phenomenon called the Greenhouse Effect.
Phenomenon – an occurrence or fact that can be perceived by the senses.

5. Climate Zones Three main climate zones: Polar – very low angle
Temperate
Tropical – near the equator
Caused by differences in heating of the Earth’s surface.
Latitude
Unequal heating of the surface results in currents

6. Wind currents occur because warm air rises and cool air sinks.
Where would you expect to find warm air rising? Cold air sinking?
The same pattern occurs in the ocean’s.
Wind over the water’s surface also creates currents.
Landmasses also have affect on currents.
Example: Rain shadow

7. Latitude determines the angle of the sunlight striking the earth

9. What Shapes Ecosystems

10. Biotic – Biological or living factors that influence organisms in an ecosystem
Ex. Plants and animals
Abiotic – Physical or non-living factors that influence organisms in an ecosystem
Ex. Temperature, soil type, sunlight, etc.

11. Habitat The area where an organism lives
Contains both biotic and abiotic factors

12. Niche
Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
An organism’s habitat is its address; its niche is its occupation.
Example: Lion lives in the savannah but it survives in that habitat by being a top level consumer.

13. Example of Niche for Anoles Lizard

14. Community Interactions
Competition
Predation
Symbiosis
Mutualism
Commensalism
Parasitism

15. Competition
This occurs when organisms try to use the same *resources (necessities of life).
Often results in one organism dying out
Competitive Exclusion Principle – No two species can occupy the same niche in the same habitat at the same time

16. Predation
One organism (predator) captures and feeds on the other (prey)

17. Symbiosis Occurs when two species live closely together Three types:
Mutualism
Commensalism
Parasitism

18. Mutualism Both species benefit from the relationship

19. Commensalism One species benefits while the other is neither helped nor harmed

20. Parasitism One species benefits by living in or on the other and the other is harmed

21. Ecological Succession
The series of predictable changes over time is succession.
Ecosystems constantly change due to natural and human influences.
Ex: Further disturbances, long term climate changes, introduction of non-native species

22. Primary Succession occurs on bare rock surfaces where no soil exists
Primary Succession occurs on bare rock surfaces where no soil exists. Ex: Lava flow or glacier melt

23. *Pioneer species are the first species to populate an area following a disturbance that causes primary succession. Ex: Lichens

24. Secondary Succession occurs when a disturbance changes a community without removing the soil

25. Climax communities are those that seem to be stable and undergoing no more change. Changes may occur very slowly due to climate changes or introduction of non-native species

26. Biomes
Biomes are groups of communities that cover large areas and are characterized by certain soil and climate conditions and particular assemblages of plants and animals.
Each biome is identified by its particular set of abiotic factors and characteristic ecological community and organisms.

27. Tolerance - plants and animals ability to survive under conditions that differ from their optimal (most desirable or favorable) conditions Microclimate – climate conditions in a small area that differ significantly from the climate of the surrounding area

28. Aquatic Ecosystems
Determined by depth, flow, temperature, and chemistry of the water (salts, nutrients and oxygen).
Grouped by the abiotic factors that affect them (different than land biomes which are determined by biotic factors)
Three main categories of Aquatic Ecosystems
Freshwater
Estuaries
Marine

29. Freshwater Ecosystems
Flowing water: Rivers, streams, creeks, and brooks
Standing-water: Lakes and ponds
Plankton- tiny organisms that live in fresh or saltwater environments
Phytoplankton - single-celled algae are producers in aquatic food webs
Zooplankton – tiny animals that feed on phytoplankton

30. Freshwater wetlands: an ecosystem that has water covering the soil or is present at or near the surface for a portion of the year
Very productive ecosystems; important breeding grounds for organisms (birds and insects)
Bogs, marshes and swamps
Water can be flowing or standing and fresh, salty or brackish(mixture of fresh and salty)

31. Estuaries Wetlands formed where rivers meet the sea
Contain a mixture of fresh water and salt water
Affected by tides
A lot of detritus (organic material that provide food for organisms at base of food web) from primary producers
Examples: Salt marsh-Chesapeake Bay and Mangrove swamp-Florida Everglades

32. Marine Ecosystems
Photic Zone - well-lit upper layer; producers can photosynthesize here (0 to 200 meters)
Aphotic Zone – Sunlight can not penetrate due to depth (200 meters and deeper)
Other zones based on depth and distance from shore: intertidal zone(close to shore), coastal zone, open ocean, benthic zone(ocean floor)