1. Ecology & the Flow of Energy in the Ecosystem

2. Ecology
The study of the interactions of organisms with one another and their physical environment

3. Both biotic and abiotic factors in a large area
Ecosystem
A self-sustaining collection of organisms and their physical environment
Both biotic and abiotic factors in a large area
                                                    

4. Biotic & Abiotic Factors
Living organisms
Abiotic =
Nonliving
Soil,Air,Water

5. Energy in Ecosystems
Energy flows into the biological world from the SUN, the ultimate source of all energy.

6. Producers
Producers are autotrophs… they can make their own food through photosynthesis
Plants, some bacteria and algae

7. Consumers
Eat other organisms to obtain energy
Example: cows, humans…

8. Detrivores
Organisms that obtain energy by eating organic wastes or dead bodies.
Ex. Vultures

9. Decomposers
Break down organic wastes (feces, urine, dead leaves or bodies) and cause decay.
Receive energy from every other type
Responsible for the final step in the food chain
Example:
Earthworms, maggots, fungi, and some bacteria

10. How is energy passed along an ecosystem?
Pyramid of Energy
Trophic Levels:
Movement of energy through an ecosystem
Levels of energy away from the sun (ulitmate source of energy)
Who eats who in the food chain
Shown as food chains, webs & pyramids

11. Food Pyramid
3rd Trophic Level – animals that feed on plant eaters or other flesh eaters (carnivores) Ex - Tiger
- omnivores eat both plants & animals. Ex - humans
2nd Trophic Level – animals that eat plants (herbivores) Ex - cow
1st Trophic Level – producers/autotrophs Ex - plants
On average, only 10% of the energy in any trophic level will be transferred to the next level.

12. Food Pyramid Tertiary consumer Secondary consumer Primary consumer
Producers

13. Food Chains & Food Webs
Most animals feed on more than one trophic level and feed on several different species at each trophic level. Making up a food chain and eventually a food web.

14. Food Chain
ONLY ONE source of food
Less stable

15. Food Web More than one choice of food
Several food chains linked together
More stable
More Common

16. Population Ecology

17. Population Number of Individuals Same Species
Live together in one area or place

18. What dynamics might be involved in predicting population growth?
Population Size
Population Growth Rate
Carrying Capacity
Limiting Factors

19. Population Size Number of individuals in a population
Growth occurs when the birthrate is greater than the death rate.

20. Population Growth Curves
Exponential
growth:
Population increases by a constant proportion per unit of time
At this growth rate the population exhibits a J-shaped curve

21. Population Growth Curves
Logistic growth:
Population increases rapidly for a period of time, its growth begins to slow, and ultimately, growth stops.
At this growth rate the population exhibits an S-shaped curve.
K (carrying capacity) = maximum population size that an environment can support K

22. Factors That Control Population Growth
Populations don’t grow indefinitely because of Limiting factors.
Limiting Factors:
Competition
Predation
Parasitism
Crowding
Stress
Disease

23. Competition
Situation in which two or more organisms attempt to use the same scarce resource (this could be a food source, a good location for capturing sunlight by plants, a particular nutrient, etc…)

24. Predation
A relationship between two organisms in which one organism (predator) kills and devours another organism (prey).

25. Parasitism:
The relationship between two organisms where one organism benefits (parasite) and the other is harmed (host).
Example: Tapeworm
You are harmed because it lives off your intestinal fluids
Segments break off to form a new worm!

26. Biodiversity
The number of species living within an ecosystem.

27. How Populations Evolve
Hardy-Weinberg Principle
The frequencies of alleles in a population do not change unless evolutionary forces act on the population.
p2 + 2pq + q2 = 1

28. How Biodiversity Impacts Population Growth
6 forces that cause populations to evolve:
Mutation – ultimate source of all variation
Migration – movement of organisms from one population to another, creates gene flow.
Nonrandom mating – when individuals prefer to mate with others of their own genotype, inbreeding is an example.
Genetic drift – random change in response to their environment.
Natural selection –Survival of the fittest.
Extinction- species that have disappeared permanently.

29. Organism Interrelationships

30. Organism Interrelationships: Symbiosis= a close long term relationship between two or more species
Beneficial:
Mutualism=
Both benefit
Commensalism=
Only one benefits & other is not harmed or helped
Harmful:
Parasitism=
One benefits &
Host slowly harmed

31. Mutualism Lichen=Fungus + algae Fungi carbon dioxide moisture Algae
(Both Benefit)
Lichen=Fungus + algae
Fungi
carbon dioxide
moisture
Algae
food
Oxygen

32. Commensalism (One Benefits)
Whale
unharmed
Barnacles
Protection from predators
Transportation to new food sources

33. Commensalism (One Benefits)
Clown fish dwell among the tentacles of tropical sea anemones. The anemomes are capable of stinging most fishes, but the clown fish possess a special mucous coating that somehow prevents the discharge of the anemone's stinging cells. The fish is protected from predators by the stinging cells.

34. Parasitism:
The relationship between two organisms where one organism benefits (parasite) and the other is harmed (host).
Example: Tapeworm
You are harmed because it lives off your intestinal fluids
Segments break off to form a new worm!

35. Cycles

36. Cycles within Ecosystems
Almost everything within an ecosystem is recycled.
Water, carbon, nitrogen & phosphorus pass from the nonliving environment to living organisms & then back to the environment.

37. Water Cycle
Water is the most important, non-living component of the ecosystem.
Nonliving cycle: involves condensation, precipitation, & evaporation.
Living cycle: involves plants in a process called transpiration.

42. Human Impact on the Environment

43. Human Impact on the Environment
How much trash do you think you throw away?
How many times a day does a person pollute the environment?
How many lakes and forests are killed by acid rain?

44. Pollution
Pollution is anything potentially harmful that humans add to the environment.
Pollution can drastically damage the health of ecosystems as well as the health of human beings.

45. Air Pollution Mainly caused by the burning of fossil fuels.
Many forms:
- Carbon Monoxide
- Nitrogen Oxide

46. The Ozone Layer
Consists of a layer of gas that is responsible for keeping UV radiation from reaching the earth’s surface.
It is being destroyed by chlorofluorocarbons (CFC’s)
CFC’s found in coolant in refrigerators & air conditioners, and the propellant in aerosol cans.
1 chlorine molecule destroys 100,000 ozone molecules.

47. The Ozone Layer

48. Acid Rain and Our Nation’s Capital
Occurs when air pollutants get mixed with rain in the atmosphere.
The product is sulfuric acid which is falls back to earth in rain and snow.
Pure water has a pH of 7.0 (neutral)
Normal rain has a pH of about Acid rain has a pH below the 5.6 Avg. The pH in northeast US is 3.8.
Acid Rain and Our Nation’s Capital
Marble surfaces exposed to acid rain
develop a rough "sugary" texture
because the calcite grains are loosened
as the edges dissolve in the rain water. Column capital volute,
Jefferson Memorial, Washington, D.C.

49. Acid Rain
NaOH

50. Greenhouse Effect
Caused when sunlight reflected from earth’s surface is trapped as heat by carbon dioxide gas.
Scientists predict an average temperature increase of 1-5 degrees C by 2050.
How does this impact the environment?

52. Resources Renewable resources:
Resources that replenish themselves naturally.
Example:
Trees
Nonrenewable resources:
Resources that do not replenish themselves naturally.
Examples:
Extinct species
Fossil fuels such as oil and gas
Trees are a renewable resource, but a forest ecosystem is nonrenewable. Why?
New trees can be planted and grown to replace those cut down, but an ecosystem involves a complex web of relationships that are established over very long periods of time.

53. How pollution effects our Resources
Pollution has led to a rapid draining of fuel supplies.
The known reserves of oil and natural gas will be nearly depleted by the middle of the next century.
Fossil fuels are nonrenewable resources.
Nonrenewable resources do not replenish themselves naturally, whereas renewable resources do.

54. Solutions to Pollution
Reduce pollution by proper waste disposal and recycling
Conserve nonrenewable resources
Reduce consumption of natural resources
Conserve energy
Curbing human population growth

55. Waste disposal & Recycling
Solutions:
Recycle as much as possible
Aluminum products
Glass containers
Office & school paper
Newspaper
Many plastic materials
Buy products that contain recycled materials
Properly dispose of toxic and hazardous materials
Household insecticides
Oven cleaners
Furniture cleaners
Oil-based paint
Motor batteries & oil
Each year, Americans generate 153 million tons of garbage. This is dumped into landfills or is burned creating air pollution.

56. Conserving Nonrenewable Resources
Topsoil for Agriculture The world has lost ¼ of its topsoil due to erosion from clearing of trees and vegetation and cultivating crops.
Ground water (water trapped beneath the soil) Groundwater is being depleted by watering lawns, washing cars, and running fountains. It is also being polluted by poor disposal of chemical wastes.
Species are disappearing. About 1/2 of the world’s tropical rainforests have been destroyed. At this rate, most of the world’s rainforests will be gone in 40 years. It is estimated that 1/5 or more of the world’s species will become extinct, mope than a million species lost, if the rainforests are destroyed.