1. Ecology The Food Web

2. 13.4 Food Chains And Food Webs 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 - 13.4 Food 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 - 13.4 Food Webs Which organism, if removed, would impact this food web the most?

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

6. Ecology -13.4 Food 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 – 13.5 Cycling 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 - 13.5 Cycling 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 - 13.5 Cycling 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 - 13.5 Cycling 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 ClipOxygen Cycle Clip oxygen respiration Carbon dioxide photosynthesis

12. fossil fuels photosynthesis carbon dioxide dissolved in water decomposition of organisms respiration carbon dioxide in air photosynthesis combustion respiration Ecology - 13.5 Cycling of Matter Carbon is the building block of life. –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.

13. 13.5 Cycling of Matter nitrogen in atmosphere animals denitrifying bacteria nitrifying bacteria nitrifying bacteria ammonium ammonification decomposers plant nitrogen-fixing bacteria in soil nitrogen-fixing bacteria in roots nitrates nitrites The nitrogen cycle mostly takes place underground. –Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation. –Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil.

14. 13.5 Cycling of Matter –Ammonia released into the soil is transformed into ammonium. nitrogen in atmosphere animals denitrifying bacteria nitrifying bacteria nitrifying bacteria ammonium ammonification decomposers plant nitrogen-fixing bacteria in soil nitrogen-fixing bacteria in roots nitrates nitrites –Nitrifying bacteria change the ammonium into nitrate. –Nitrogen moves through the food web and returns to the soil during decomposition.

15. 13.5 Cycling of Matter geologic uplifting rain weathering of phosphate from rocks runoff sedimentation forms new rocks leaching phosphate in solution animals plants decomposers phosphate in soil  The phosphorus cycle takes place at and below ground level. –Phosphate is released by the weathering of rocks. –Phosphorus moves through the food web and returns to the soil during decomposition. – Phosphorus leaches into groundwater from the soil and is locked in sediments. – Both mining and agriculture add phosphorus into the environment.

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

17. energy transferred energy lost 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. 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. tertiary consumers secondary consumers primary consumers producers 75 g/m2 150g/m2 675g/m2 2000g/m2 producers 2000g/m2

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