Ecology Review

1. Ecology Review Living things do not live in vacuums, their daily lives are based on interactions with both living and nonliving things. What is an ecosystem? Groups of organisms and their physical environment What is the Biosphere? All forms of life on Earth are connected in a biosphere

2. Ecology Terms Organism living thing Population groups of living things Communitygroup of populations Ecosystemgroup of communities Biome Group of ecosystems Biosphere Group of biomes

3. There are two main components of an ecosystem: Biotic(living) & Abiotic(nonliving) Populations of Inorganic nutrients, organisms. physical features, water, temperature, and wind.

4. Biotic Components: A Closer Look Autotrophs are producers that produce food for themselves and for consumers. How do autotrophs make food? Photosynthesis and chemosynthesis Heterotrophsare consumers that take in premade food.

5. Biotic components

6. Consumers Vocabulary: Herbivores – animals that eat plants Carnivores – animals that eat other animals Omnivores – animals that eat plants and animals Decomposers - bacteria and fungi, that break down dead organic waste. Detritus- partially decomposed organic matter in the soil and water; beetles, earthworms, and termites are detritus feeders.

7. Consumers

8. Consumer Levels Primary consumer – anorganism that gets its energy from plants (producers) Secondary consumer – anorganism that gets its energy from primary consumers Tertiary consumer – carnivores that eat other carnivores; a top-level consumer, usually the top predator in the food chain

9. Biotic Interactions Organisms occupy a specific role, or niche, in an environment • Competition  fight between individuals or species for food/habitat/mate • Predation  action where a hunter feeds on prey • Symbiosis  situation where 2 organisms interact with each other and both benefit from this interaction

10. Energy Flow • What is energy flow? • The movement of energy through the organisms in an ecosystem • What direction does energy flow through an ecosystem? • Sun  Producers  Various levels of consumers

11. As energy flows from autotrophs (producers) to heterotrophs (consumers) much of the energy is lost before the consumer can use it. • In what forms is energy lost? • Heat • Initial energy from an ecosystem comes from a consistent supply of solar energy • **Remember energy in an ecosystem may be transferred or converted but will not be created nor destroyed**

12. Energy balances

13. Nature of an ecosystem

14. Food chains vs. food webs • What is a food chain? • A diagram that links organisms together by who eats whom • Starts with plant life and ends with an animal. • Most food chains have no more than 4 or 5 links • Arrows show the direction energy is flowing • EXAMPLE: tree  giraffe  lion

15. Food chain

16. Most consumers feed on and are eaten by more than one other consumer • What is a food web? • A combination of several food chains showing all of the possible energy pathways • What is a trophic level? • All of the organisms that feed at a particular link of the food chain/web

17. Grazing food web – The upper portion of a food web based on a living plant as the producer Detrital food web – The lower portion of a food web based on detritus

18. Forest food webs

19. Ecological Pyramids • Why are food chains so short? • Only about 10% of energy is useable from one trophic level to the next • The number organisms drastically decreases as you go up in level of a food chain • What is an ecological pyramid? • A series of blocks representing the biomass of particular organisms on a particular trophic level • What is biomass? • The amount of living material in the population of an organism

20. Ecological pyramid

21. Biochemical cycles • What are biochemical cycles? • The path by which important nutrients/molecules travel through an ecosystem. • 3 Important Cycles: • Water Cycle • Carbon Cycle • Nitrogen Cycle

22. The Water Cycle • Water movement: • Land  Atmosphere: • Liquid  Gas • Evaporation from rivers, lakes and oceans • Transpiration from plants • Atmosphere  Land • Gas  Liquid • Precipitation over land and bodies of water • Runoff forms bodies of water (lakes, rivers, oceans) • Ground water seepage into aquifers

23. The water cycle

24. The Carbon Cycle • Carbon Movement: • Land/Water  Atmosphere • Respiration • Combustion • Atmosphere Land/Water • Photosynthesis • Dissolved CO2 • ** Carbon is stored as _fossil fuels__ from decaying organisms.**

25. The carbon cycle

26. The Nitrogen Cycle • Nitrogen Movement: • Nitrogen Fixation  Bacteria found in legume roots converts N2 gas into Ammonia (NH4) • Decomposers break down waste and organic remains into Ammonia (NH4) • Nitrification  bacteria convert ammonia into Nitrite (NO2) and Nitrate (NO3) to be used by plants • Denitrification  Bacteria converts ammonia back into Nitrogen gas (N2)

27. The nitrogen cycle

28. The Phosphorus Cycle The phosphorus cycle is a sedimentary cycle. Only limited quantities are made available to plants by the weathering of sedimentary rocks; phosphorus is a limiting inorganic nutrient. The biotic community recycles phosphorus back to the producers, temporarily incorporating it into ATP, nucleotides, teeth, bone and shells, and then returning it to the ecosystem via decomposition.

29. The phosphorus cycle

30. Changes to Ecosystems • Air Pollution  Burning of fossil fuels releases CO2, SO2, and NO2,NO3 into atmosphere. Results in climate change, acid rain, damage to ozone layer

31. Habitat Destruction • Over past 50 years, 50% of tropical forests have been cleared for timber or farmland (deforestation) • Loss of habitat often means extinction for organisms within that habitat

32. Invasive Species • Introduction of species to new habitats, usually by humans