1. Unit 2-Ecology Chapter 3 The Biosphere 3.1 What is Ecology?

2. The Biosphere Consists of all life on Earth and all the parts of the Earth where life exists Includes all organisms on Earth and where they live Ecology is the study of the interactions of all of the organisms and their environments in the biosphere

3. Organization in the Biosphere 1. S pecies- similar organisms that can breed 2. P opulation- group of individuals of the same species living in the same area 3. C ommunity- different populations living together in the same area 4. E cosystem- all the organisms in a certain place together with their physical environment 5. B iome- a group of ecosystems with similar climates and typical organisms 6. T he Biosphere- all living things from all biomes on the planet

4. Environments Environments are the conditions or factors surrounding an organism Consist of biotic and abiotic factors

5. Biotic Factors Any living part of the environment with which an individual may interact Includes animals, plants, fungi, bacteria, etc.

6. Abiotic Factors Any nonliving part of the environment Examples: sunlight, heat, precipitation, humidity, wind, water, soil, etc.

7. Biotic and Abiotic Factors Work Together Examples: -Frogs live in mud along the shores of ponds. -The mud is abiotic but contains mold and decomposing plant material, which feeds bacteria and fungi- all biotic -Trees (biotic) provide protection from the sun (abiotic) for organisms in an environment.

8. 3.2 Energy, Producers, and Consumers

9. Energy Organisms operate by expending energy Organisms can not create energy, they must obtain it Different organisms get their energy in different ways

10. Autotrophs Organisms that capture energy from sunlight or chemicals and convert it into forms of energy that living cells can use Autotrophs feed themselves, and also provide food for other organisms Are considered primary producers- the first makers of energy-rich compounds that can be used by other organisms

11. Primary Producers Most commonly use energy from the sun to create sugars and starches (photosynthesis) Add oxygen to the air and remove carbon dioxide Important examples: algae, photosynthetic bacteria

12. Do All Primary Producers Use Energy From the Sun? No! Some, very specialized, organisms turn the energy in chemicals into carbohydrates. This is called chemosynthesis –Organisms that do this are often found at the deep ocean floor, or in other extreme environments –Mostly bacteria

13. Heterotrophs Can not make their own food so must eat other organisms. Also called consumers (because they consume other organisms)

14. Types of Consumers Classified by the way they acquire energy Carnivores- kill and eat other animals Herbivores- eat plant materials Omnivores- eat both plant and animal materials Scavengers- consume carcasses of organisms that have died or that were killed by predators Decomposers- feed by chemically breaking down organic matter (fungi and bacteria) Detritivores- feed on detritus particles, debris from decomposing plants and animals (earthworms)

15. 3.3

16. Energy Flows by Feeding Energy flows through an ecosystem in a one way direction from producers to consumers Food Chain- a series of steps in which organisms transfer energy by eating and being eaten. Phytoplankton = algae that is floating and not attached to something

17. Food Webs Most ecosystems are not simple enough to be represented by a food chain Food web- a network of complex interactions formed by the feeding relationships among the organisms of an ecosystem AlgaePlants

18. Decomposers and Detritivores Most primary producers die without being eaten Decomposers (bacteria and fungi) break down this dead material into detritus –This releases nutrients into the soil for new primary producers to grow (“recycles nutrients”) Detritus is eaten by detritivores (like crayfish, grass shrimp, and worms)

19. Food Web Disturbances Environmental changes can cause changes in a food web Krill are small, shrimplike, swimming animals ( a type of zooplankton) Play a major role in the Antarctic food web

20. Food Web Disturbances How would decrease in the krill population effect the food web Antarctic food web?

21. Trophic Levels Each step of a food chain or food web is called a trophic level First trophic level- always primary producers All other trophic levels are occupied by different types of consumers

22. Ecological Pyramids Illustrations used to show the amounts of energy or matter in each trophic level of a food web Three types of pyramids: energy, biomass, and numbers

23. Pyramids of Energy Only a small amount of energy in one trophic level is actually passed to the next level up. On average, only 10% The rest of the energy is expended by the organisms to do life processes (like growth, reproduction, respiration, etc.), and released as heat Pyramids of energy show the amount of energy available at each trophic level How much of the energy available to the producers is available to the third-level consumers?

24. Pyramids of Biomass Biomass is the total amount of living tissue in a trophic level Measured in grams per unit of area The amount of biomass at each trophic level is partially determined by how much energy is available in that trophic level

25. Pyramids of Numbers Show the number of individuals at each trophic level Usually has a similar shape to the pyramid of biomass In some cases the pyramid of numbers may be upside down compared to the pyramid of biomass –This occurs if the consumers are much less massive than what they feed on (Ex: thousands of insects feeding on a single tree) Pyramid of Numbers

26. 3.4 Cycles of Matter

27. Matter is Recycled Within and Between Ecosystems This is different than the one-way flow of energy through an ecosystem Biogeochemical cycles- cycles though which elements pass from one organisms to another and among parts of the biosphere As matter moves through these cycles, it is changed (or transformed) It is never created or destroyed!!

28. The Water Cycle

29. Nutrient Cycles Nutrients are chemical substances that organisms need to sustain life The cycling of carbon, nitrogen, and phosphorus through organisms and the environment are especially important –The element oxygen helps these three nutrients move through their cycles –Oxygen is released during photosynthesis and used in cellular respiration

30. The Carbon Cycle

31. The Nitrogen Cycle Nitrogen is required to make amino acids and nucleic acids Is found in many forms Nitrogen gas is the most abundant form but only bacteria can use this form directly –These bacteria turn nitrogen gas into ammonia, then nitrates and nitrites by the process of nitrogen fixation These forms can then be used by primary producers to make proteins and nucleic acids Some bacteria turn the nitrates and nitrites back into nitrogen gas by denitrification

32. The Nitrogen Cycle

33. Humans Contribute Nitrogen to the Biosphere Fertilizers contain nitrogen and phosphorus and are used to assist plant growth Excess fertilizer is often carried into bodies of water when it rains This causes an increase in the growth of algae, creating an algal bloom

34. Why are Algal Blooms Harmful? The decay process for dead algae uses up oxygen in the water, resulting in death of other plants and animals Other algae releases toxins into the water Ex: red tide

35. The Phosphorus Cycle Phosphorus spends little time in the atmosphere compared to carbon and nitrogen