Ecology

1. Ecology The Food Web

2. A food web shows a complex network of feeding relationships. • An organism may have multiple feeding relationships in an ecosystem. • A food web emphasizes complicated feeding relationships and energy flow in an ecosystem. How many trophic levels are present in this food web?

3. Ecology - 13.4Food Webs • The Anatomy of the Arrow • - In a food web, the arrow is always pointing to the animal that is doing the “eating”. • - The arrow is signifying the energy flow from the organism that is being consumed, to the organism that is receiving that energy through the action of consumption.

4. Ecology - 13.4Food Webs Which organism, if removed, would impact this food web the most?

5. Ecology - 13.4Food Webs Now, introduce the lion. How might the food web energy flow change with the presence of the lion?

6. Ecology -13.4Food Webs • - At every every link in the food web, energy is going to be stored in the organism (i.e eating, growth, bodily repair, reproduction). • - At every link some energy will be dissipated into the environment (i.e. heat, waste product)

7. 3-2-1 Exit Ticket List 3 things about this arrow that makes it important in a food web. List tell me 2 facts about this food chain. Give me 1 real life connection you made with the lesson.

8. Ecology – 13.5Cycling of Matter • Law of Conservation of Matter: • Matter can neither be created nor destroyed; however it can change form. • Matter may change form many times, but the amount of matter will always remain constant.

9. Ecology - 13.5Cycling of Matter • The Hydrologic Cycle (water cycle): • Circular pathway of water on the planet, stretching from the atmosphere to the surface, underneath the ground, then back up into the atmosphere again.

10. Ecology - 13.5Cycling of Matter • Biogeochemical Cycle: *Elements essential for life also cycle through ecosystems. - A biogeochemical cycle is the movement of a particular chemical through the biological and geological parts of an ecosystem. - The main processes involved in the oxygen cycle are photosynthesis and respiration.

11. Ecology - 13.5Cycling of Matter • The Oxygen Cycle: • Oxygen cycles indirectly through an ecosystem by the cycling of other nutrients. • Organisms need oxygen to perform cellular respiration. - Plants release oxygen as a waste product during photosynthesis. • Humans and other organisms will take in the oxygen, and in turn release carbon dioxide back into the atmosphere. • Oxygen Cycle Clip oxygen photosynthesis respiration Carbon dioxide

12. carbon dioxide in air respiration combustion photosynthesis respiration photosynthesis decomposition of organisms carbon dioxide dissolved in water fossil fuels Ecology - 13.5Cycling of Matter • The carbon cycle moves carbon from the atmosphere, through the food web, and returns to the atmosphere. • Carbon is emitted by the burning of fossil fuels. • Some carbon is stored for long periods of time in areas called carbon sinks. • Carbon is the building block of life.

13. nitrogen in atmosphere animals plant nitrates nitrogen-fixing bacteria in roots decomposers nitrifying bacteria ammonification nitrites nitrogen-fixing bacteria in soil ammonium nitrifying bacteria denitrifying bacteria • Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation. • Some nitrogen-fixing bacteria live innodules on theroots of plants;others livefreely inthe soil. • The nitrogen cycle mostly takes place underground.

14. nitrogen in atmosphere animals plant nitrates nitrogen-fixing bacteria in roots decomposers nitrifying bacteria ammonification nitrites nitrogen-fixing bacteria in soil ammonium nitrifying bacteria denitrifying bacteria • Nitrifying bacteria change the ammonium into nitrate. • Nitrogen moves through the foodweb and returnsto the soil duringdecomposition. • Ammonia released into the soil is transformed into ammonium.

15. rain geologic uplifting weathering of phosphate from rocks runoff plants animals phosphate in soil phosphate in solution leaching sedimentation forms new rocks decomposers • Phosphate is released by the weathering of rocks. • Phosphorus moves through the food web and returns to the soil duringdecomposition. • The phosphorus cycle takes place at and below ground level. • Phosphorus leaches into groundwater from the soil and is locked in sediments. • Both mining and agriculture add phosphorus into the environment.

16. Ecology – 13.6Pyramid Models • An energy pyramid shows the distribution of energy among trophic levels.

17. energy lost energy transferred An energy pyramid shows the distribution of energy among trophic levels. • Energy pyramids compare energy used by producers and other organisms on trophic levels. • Between each tier of an energy pyramid, up to 90 percent of the energy is lost into the atmosphere as heat. • Only 10 percent of the energy at each tier is transferred from one trophic level to the next.

18. tertiary consumers 75 g/m2 150g/m2 secondary consumers primary consumers 675g/m2 2000g/m2 2000g/m2 producers producers Other pyramid models illustrate an ecosystem’s biomass and distribution of organisms. • Biomass is a measure of the total dry mass of organisms in a given area.

19. 5 tertiary consumers secondary consumers 5000 primary consumers 500,000 producers 5,000,000 producers 5,000,000 • A pyramid of numbers shows the numbers of individual organisms at each trophic level in an ecosystem. • A vast number of producers are required to support even a few top level consumers.