2. 3.1 – What is Ecology? Interactions and Interdependence Ecology – the study of interactions among organisms and their environment Oikos (ec) – Greek word meaning house Ology – means study of

3. Levels of Organization The levels of organization that ecologists study include: Individuals Species – group of similar organisms that can breed and produce fertile offspring Populations – group of individuals of the same species that live in the same area and interbreed Communities – several populations that live together in an area

4. Ecosystem – The interaction of all the organisms and the environment in a given area Biome – a group of ecosystems that have the same climate Biosphere – part of Earth in which life exists including land, water and atmosphere It extends about 8km above the Earth’s surface to about 11km below If you could shrink earth to the size of an apple, the biosphere would be thinner than the apple’s peel

5. Biotic and Abiotic Factors Biotic Factors – all the living organisms in an ecosystem Example: tree, bird, bacteria, fungi Abiotic Factors – nonliving factors in an ecosystems Example: temperature, precipitation, wind, soil, sunlight, humidity Habitat – area where an organism lives including biotic and abiotic factors Niche – the role and position a species has in its environment No two species can share the same niche in the same habitat

6. 3.2 – Energy Flow Sunlight is the main energy source for life Autotrophs Make their own energy Convert sun energy into chemical energy Also called a producer Plants are the main autotrophs on land Algae are the main autotrophs in water

7. Some autotrophs can produce food in the absence of light Chemoautotrophs – organisms use chemical energy to produce carbohydrates Live in… Volcanic vents Deep ocean Hot springs Marshes

8. Heterotrophs Get energy from other organisms Unable to make its own energy Also called consumers Types of Heterotrophs Herbivores Eats only plants Example: cows, deer, rabbits, bees, elephants, squirrels

9. Carnivores Eats only animals Example: snakes, dogs, lions, crocodiles Omnivores Eats plants and animals Example: humans, bears, crows

10. Detrivores Eat decomposing bits of organic matter Example: mites, earthworms, snails, crabs Decomposers Break down organic matter Example: bacteria and fungi Scavenger Ingest nonliving plants and animals Example: vulture, termite, beetle

11. Feeding Relationships Food Chain – a straight line series of steps by which energy is stored and passed on to higher trophic levels

12. Food Web – a network of crossing interlinked food chains that shows all the possible feeding relationships at each trophic level

13. Trophic Levels – the different feeding relationships in an ecosystem. Plants and other producers are 1 st trophic level Consumers make up the 2 nd, 3 rd, or higher trophic levels Each consumer depends on the trophic level below it for energy Energy is transferred from one trophic level to another and is never 100% At each trophic level only 10% of the energy taken in by the organism is stored. Energy is passed through no more than four or five trophic levels

14. Ecological Pyramids Ecological Pyramid – a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web

16. 3-3 Cycles of Matter Properties of Water Water is perhaps the most important compound in living organisms Water serves as a means of material transportation in organisms. Ex. Blood (is mostly water) Hydrogen bond – attraction between opposite charged molecules (H + O - ) Are important because they help hold many large molecules such as proteins together. Water resists changes in temperature Water requires more heat to increase its temperature.

17. Water is like an insulator maintains homeostasis Water is one of the few substances that expands when it freezes. Ice is less dense than liquid Cohesion – attraction between like molecules Cohesion creates tension Tension – inward pulling on water molecules at the surface Adhesion – attraction between different molecules

18. Biogeochemical Cycles – chemicals and nutrients are transferred from environment into organisms then back to the environment

19. The Water Cycle Evaporation – process by which water changes from a liquid to a gas Transpiration – loss of water from plants by the process of evaporation How does water move up a plant? Xylem – tubes in plants that transport water from roots to leaves. On sunny days, water evaporates from leaves Adhesion & Cohesion pulls up more water molecules into leaf cells Condensation – water vapor changes to a liquid Precipitation – water returns to the earth (rain, snow, hail)

20. Click to view animation.

21. 1 2 3 7 6 5 4

22. CO 2 Organism eats plants C 6 H 12 O 6 Respiration Burning Trees Burning Fossil Fuels Volcanic Activity Oil Coal Decomposition Root Uptake Photosynthesis 1 2 3 4 5 6 7 8 9 10 11

23. Gaseous Nitrogen N 2 Ammonification Bacteria convert wastes and decomposing organics to NH 3 → NH 4 Nitrogen Fixation Bacteria in the soil convert N 2 → NH 3 → NH 4 Denitrification Bacteria convert NO 3 → N 2 Nitrification Bacteria convert NH 4 → NO 2 → NO 3 Autotrophs can take up NH 4 and NO 3 1 2 3 5 4 6

24. Humans are harming the nitrogen cycle by: Deforestation Conversion of grasslands for agriculture Sewage enters waterways Fossil fuel burning Vehicles having combustion engines releases NO 2