Unit 2: Ecology

1. Unit 2: Ecology The Biosphere

2. What is Ecology? Ecology is the scientific study of interactions among organisms and between organisms and their environment, or surroundings Can you think of interactions between organisms in the environment?

3. The Biosphere The Biosphere contains the combined portions of the planet in which all of life exists, including land, water, and air or the atmosphere Interactions within the biosphere create a web of interdependence between organisms and the environment in which they live.

4. Levels of Organization To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere

5. Levels of Organization An individual is the single organism that makes up a population (a group of the same animal, plant, etc. like a species) A community is multiple populations (multiple species) like deer, squirrels, and bears that may all live in the same area All of the organisms and their nonliving, physical environments make up an ecosystem Multiple ecosystems come together to make up the biome, which has similar environments (like water, air, woods, etc.) The highest level (largest) is the entire biosphere which is all the biomes on the planet

6. So, How do scientists study these groups??? Scientists gather information using three basic approaches Observing – what species live here?, how many animals in the herd? Experimenting – use artificial environments to test hypotheses Modeling – make models to help predict and understand relationships of larger groups that would otherwise be difficult to observe

7. Checkpoint  What are the six different levels of organization that ecologists study? What are the three basic methods of ecological research?

8. Checkpoint  What are three ways in which you interact every day with each of the three parts of the biosphere – land, water, and air??

9. Energy Flow Where do we get all of our energy from? Can we use the sunlight?? How do WE get our energy?

10. Producers Sunlight is the main energy source for life here on Earth Some organisms don’t use the sunlight… they can use the energy stored in inorganic compounds – make their energy using chemical reactions rather than the sun.

11. A.K.A. Producers Organisms that can make their own energy (from sunlight OR from chemical means) are known as AUTOTROPHS (auto- = self & -troph = food) These organisms that can produce their own food are also called producers.

13. Where does the energy come from? Like we said, most autotrophs obtain their energy from the sun They harness this energy in a process known as ________________.

14. Where does the energy come from? Like we said, most autotrophs obtain their energy from the sun They harness this energy in a process known as Photosynthesis Plants use the energy from the sunlight to convert Carbon Dioxide and Water to Carbohydrates (sugars) and Oxygen

16. Photosynthesis Carbon dioxide reacts water in the presence of light energy to form carbohydrates and oxygen gas --or-- CO2 + H2O ------------> carbohydrates + O2 Light Energy

17. Chemosynthesis What if we don’t have light? Does this mean we don’t have life? Some organisms can make their own energy (autotrophs) without light They do this using chemosynthesis or making energy using chemical changes without light

19. What do other animals do??

20. Consumers If you cannot make your own energy like the autotrophs (or producers) than you may need to EAT THESE ORGANISMS Organisms that cannot make their own and must eat other organisms are known as consumers (they consume other animals) These are also known as heterotrophs

23. Feeding Relationships We are all tied together and all rely on each other The plants need animals to exhale carbon dioxide so that they may use the sunlight and create their own sugars and foods. This tight interdependence is known as a Food Web or Food Chain

24. Relationships Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers) The energy stored by producers can be passed through an ecosystem ……. Wait…. What is an ecosystem??

25. Relationships Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers) The energy stored by producers can be passed through an ecosystem along a food chain

27. Lets make our own!! Create a food chain with at least 4 organisms that rely on one another. Maybe….. Grass seeds --- mouse --- snake --- hawk --or-- Vegetation --- caterpillar --- bird --- coyote

28. Relationships When the feeding relationships among the various organisms in an ecosystem form a network of complex interactions, ecologists describe these relationships as a food web These tie in many organisms within an ecosystem who all rely on multiple food sources and play a large role on the stability of the ecosystem

30. Where does the energy go!?!?! These “steps” or “levels” on a food chain or food web are known as Trophic Levels As you go from level to level there are fewer organisms Many, many producers on the bottom and only a few or less consumers all the way on the top Why do you think this is so?

31. Everyone needs energy!! Each step requires energy for themselves Only about 10% is transferred from level to level… so the hawk eating the rabbit only gains about 10% of the rabbit’s energy The other 90% was used by the rabbit to live, stay warm, grow, reproduce, etc.

32. Ecological Pyramids An ecological pyramid is a diagram that shows the relative amounts of energy or matter contained at each trophic level in a food chain or food web WHAT DO YOU THINK IS ON TOP?? BOTTOM?? Grass, plants, berries, etc. are at the bottom… and are the most abundant Top predators (wolves, coyotes, mountain lions) are at the top and are the least abundant (fewest)

33. Only 10%??? Because only 10% is transferred from one trophic level to the next, there NEEDS to be MUCH more to feed the level above them Meaning, there needs to be a lot more grass than deer to feed them. There needs to be a lot more deer than coyotes to feed them too 

34. Let’s see where we are at… In your notes, ON A SEPARATE SHEET OF PAPER TO TURN IN, answer the following questions with a partner What are the two main forms of energy that power living systems? Explain the relationships in the food chain between a herbivore, a carnivore, and an omnivore What proportion of energy is transferred from one trophic level to the next in an ecosystem? Why is the amount of energy transferred from one level to the next so low? What are the eight characteristics all living things share?

35. Cycles of Matter • What is matter? • Unlike the one-way flow of energy, matter is recycled within and between ecosystems • What does it mean to “recycle” something?

36. Recycling in an Ecosystem We call this recycling process biogeochemical cycles Bio – meaning life Geo – meaning earth matter Chemical – meaning the chemicals and compounds An ecosystem recycles these materials – they never increase or decrease in amounts… just go around and around forever

37. The Water Cycle The water moves between the ocean, atmosphere, and the land Water enters the atmosphere by evaporation Water can also enter the atmosphere by leaving plants in a process called transpiration

38. The Water Cycle Water can come back down to the land and oceans by precipitation (raining, snowing, etc.) How are evaporation and transpiration related??

40. Nutrient Cycles • In addition to WATER, ecosystems must recycle nutrients also!! • There are three different types of nutrients that MUST be recycled in an ecosystem!! • The Carbon Cycle • The Nitrogen Cycle • The Phosphorus Cycle

41. #1  The Carbon Cycle • Carbon can be exchanged and recycled through an ecosystem through a variety of ways • Photosynthesis, respiration, decomposition use and release carbon and oxygen • Geochemical cycles like erosion and volcanoes release carbon dioxide into the atmosphere and oceans • Dead animals and organic matter convert to fossil fuels – burning these materials releases the carbon • Mining, cutting and burning forests, and burning fossil fuels release carbon dioxide into the atmosphere

43. #2  The Nitrogen Cycle • All organisms require nitrogen to make amino acids, which are used to make proteins • Nitrogen can be shuffled through an ecosystem in many different forms: • Ammonia (NH3) nitrogen gas (N2) • Nitrate (NO3-) nitrite (NO2-)

44. The Nitrogen Cycle Some bacteria can convert nitrogen gas into ammonia in a process known as nitrogen fixation Some soil bacteria convert nitrates into nitrogen gas in a process known as denitrification These bacterial help to recycle the nitrogen round and round and allow it to re-enter the atmosphere and environment

46. #3  The Phosphorus Cycle Phosphorus is needed to make DNA and RNA, making it very important Phosphorus is the ONLY one (out of water, carbon, and nitrogen) that DOES NOT ENTER THE ATMOSPHERE What does that mean??

47. The Phosphorus Cycle Phosphorus remains mostly on land in rock and soil minerals and in ocean sediment The rocks and soil are gradually eroded and broken down which releases the phosphorus back into the environment Where is most of the phosphorus stored in the biosphere???

49. Nutrient Limitation An ecosystem will always grow when there are available resources (food, water, NUTRIENTS) When the nutrients run out _______________. When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient

50. Fertilizers This is why farmers put fertilizer on their corps to make them grow better Fertilizers are composed of nitrogen, phosphorous, and potassium They add this to their crops and then WATER THEM!!