1. Ecology

2. What is Ecology?
Ecology is the study of interactions among organisms and between organisms and their environment.
There are many levels of organization ecologists study…

3. Levels of Organization

4. Levels of Organization
Species: can breed and produce fertile offspring
Population: same species in same area
Community: different populations in same area
Ecosystem: all organisms (biotic) in particular place; includes nonliving (abiotic) surroundings
Biome: group of ecosystems with same climate (temperature and precipitation) and similar communities
Biosphere: all portions of the planet where life exists (land, water, air, atmosphere)

5. Basic Terminology
Ecosystem – All the biotic and abiotic factors in an environment
Heat Energy – Form of “lost” energy, 90% of available energy is lost in the form of heat.
Chemical Energy – Glucose transfer in the food chain
Light Energy – Originating source of Energy from the sun (Main source of energy)

6. Energy Flow Summary
Energy flows in one direction through an ecosystem, from the sun or inorganic compounds to producers (organisms that can make their own food) through various levels to consumers (organisms that rely on other organisms for food).

7. Energy Flow Producers: Autotrophs Consumers: Heterotrophs
Photosynthesis Vs. Chemosynthesis
Consumers: Heterotrophs
Herbivores
Carnivores
Omnivores
Detritivores
Decomposers
Scavenger
Examples of Photosynthesizers – Plants, Some Protists, and Some Bacteria
Examples of Chemosynthesizers – Some Bacteria
Herbivore – Eat Only Plants ex) Sheep
Carnivore – Each only Meat ex) Hawk, Lion
Omnivore – Each Both Plants and Animals ex) Humans, Rats
Detritivore – Feed on Dead and Decaying Matter, Return Nutrients ex) Worms and Millipeds, Sea Stars
Decomposer – Break Down Dead and decaying Matter ex) Bacteria and Fungus
Scavenger – Tears Up Dead Matter ex) Vulture

8. Trophic Levels

9. Feeding Relationships
Food chain: series of steps (linear)
Food web: links all food chains together
Trophic level: each step in a chain or web

10. Ecological Pyramids

11. Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 90
percent of this
energy for
life processes.
Only 10% is transferred.

12. Biomass Pyramid Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid.

13. Pyramid of Numbers Shows the relative number of individual
organisms at each
trophic level.

14. Cycling of Nutrient and Matter
Remember: Energy flows in one direction and matter cycles.

15. Recycling in the Biosphere
Unlike the one-way flow of energy, matter is recycled.
Matter moves through an ecosystem in biogeochemical cycles.
Matter is recycled because systems do not use up matter, they transform it.

16. Four Main Cycles Water Cycle Nutrient Cycles Carbon Cycle
Nitrogen Cycle
Phosphorus Cycle

17. Water Cycle
1. When rain falls on the ground, it either soaks into the soil or runs across the surface of the soil. When rainwater runs across the land, what body of water might collect the rain?
2. From here, where might the water flow?
3. After the rain, the sun comes out and the land dries. Where does the water that had been on the land go?

18. Water Cycle Water moves between the ocean, atmosphere, and land.
Steps of the water cycle:
Evaporation Transpiration
Condensation
Precipitation
Runoff
Seepage
Groundwater

19. Water Cycle
Sketch a simple diagram of the water cycle in your notes.

20. Nutrient Cycles
Every organism needs nutrients to grow and function. Like water, nutrients are also transferred in cycles.
3 Nutrient Cycles:
Carbon
Nitrogen
Phosphorus-mostly in rocks and soil minerals

21. Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean

22. Carbon Cycle
Four main types of processes move carbon through its cycle:
Biological processes, such as photosynthesis, respiration, and decomposition, take up and release carbon and oxygen.
Geochemical processes, such as erosion and volcanic activity, release carbon dioxide to the atmosphere and oceans.

23. Carbon Cycle
Mixed biogeochemical processes, such as the burial and decomposition of dead organisms and their conversion under pressure into coal and petroleum (fossil fuels), store carbon underground.
Human activities, such as mining, cutting and burning forests, and burning fossil fuels, release carbon dioxide into the atmosphere.

24. Nitrogen Cycle
N2 in Atmosphere
NO3-
and NO2-
NH3

25. Nitrogen Cycle
Bacteria that live in the soil and on the roots of legume plants convert nitrogen gas to ammonia through nitrogen fixation.
When organisms die, their ammonia can be converted back to nitrogen gas through denitrification.

26. Phosphorus Cycle
Phosphorus is essential to living organisms because it forms part of important life-sustaining molecules such as DNA and RNA.
Phosphorus remains mostly on land in rock and soil minerals, and in ocean sediments.
It is not very common in the biosphere
phosphorus exists in the form of inorganic phosphate.
As the rocks and sediments gradually wear down, phosphate is released.
On land, some of the phosphate washes into rivers and streams, where it dissolves.
The phosphate eventually makes its way to the oceans, where it is used by marine organisms.

27. Phosphorus Cycle