Ecology:

2. Ecology: • The study of Interactions among Organisms and its environment including: • Abiotic factors are nonliving factors such as temp. soil, air, rocks • Biotic Factors are living parts of the ecosystem

3. Populations vs. Communities: • A population is a group of organisms of the same species living in a certain area • All populations interacting together in a given area is a community • Ex. Frogs + fish + algae = community

4. Habitats are: • Place in the ecosystem where an organism lives • Determined by both biotic and abiotic factors • Ex. Earthworm = moist soil, dead organic material

5. Niche: • The role of the organism in its environment • Includes feeding habits, reproduction, habitat, and what it contributes to its surrounding

7. Ecosystem is a community and its physical environment including biotic and abiotic factors

8. Autotrophic and Heterotrophic Nutrition:

9. Autotrophs: • Make their own food PRODUCERS • Provide food to consumers • Most carry out photosynthesis (solar light energy being converted into food glucose!!) • Ex. Green Plants!! • Some producers are chemosynthetic – ability to create food by using energy stored in inorganic molecules

10. Autotrophs:

11. Heterotrophs: • Are also known as consumers • Cannot make their own food • Must obtain their food from their environment

12. Heterotrophs:

13. Types of Heterotrophs include: Herbivores eat only plants

14. Types of Heterotrophs include: carnivores eat only meat • predators- kill and eat their prey • prey - the animal that is killed and eaten • scavengers feed on dead and decaying meat • ex. Buzzards, crows, hyenas

16. Types of Heterotrophs include: omnivores – eat both plant and animals • ex. US!!, bears and…???

17. Types of Heterotrophs include: Decomposers (aka. saprobes) get nutrients from breaking down dead plants & animals • Ex. bacteria, fungus, mushrooms

18. Symbiosis (Symbiotic Relationships): 2 organisms living together where at least 1 organism benefits

19. 3 types of symbiotic relationships: • Mutualism • Commensalism • Parasitism

20. Mutualism • mutualism - both organisms benefit from the association • Ex. Humans and bacteria in the digestive track • Ex. Fish in sea anemones • Ex. Flower and the bee

22. Commensalism • Commensalism - one organism benefits the other is not effected (not harmed, no benefit) • ex. Remora fish and sharks • ex. Orchids/moss living in tree

24. Parasitism: • Parasitism - one organism benefits at the cost of the other (host) • ex. parasites living in animals (tapeworm, tick) • often cause disease

26. Energy Flow in an Ecosystem: Includes: • producers (Autotrophs ) make their own food • consumers (heterotrophs) obtain or eat their food from the environment • Decomposers (a.k.a saprobes ) break down left over remains of plants and animals

27. FOOD CHAINS: • Are a transfer or 1 pathway of energy through an ecosystem • Solar Energy from the sun is converted by producers (photosynthesis) into chemical energy or FOOD

28. FOOD CHAINS cont… • Show the relationship b/w Producers and Consumers • Energy is transferred from the producer to the consumer that eats it. • Herbivores are first order consumers gaining the most energy from the producers • Omnivores and Carnivores are secondary consumers getting left over energy

29. FOOD CHAINS cont… • The feeding relationship shows the transfer of energy which forms a food chain • The transfer of energy moves from producer to consumer to decomposers • Ex. Sun plant  grasshopper  bird  cat Decomposers

30. Examples of food chains: Producers consumers consumers consumers (plants) (1st level) (2nd level) (3rd level) Grass à grasshoppers àrobins à hawk

31. FOOD WEB • food chains (1 pathway of energy) which are interconnected = food webs • Food webs are many food chains interacting together Each arrow in the food web means consumed (EATEN) by…

32. FOOD WEB

33. Energy Pyramids ARE: Another way of showing the flow of energy in an ecosystem

34. Energy Pyramids Each step in a feeding relationship is called a trophic level • 1st trophic level = producers • 2nd trophic level = primary consumers • 3rd trophic level = secondary consumers

36. The greatest amount of energy is at the bottom of the pyramid (producers), the least amount of energy is at the top.

37. 90% of Energy is lost moving at each level, only 10% is transferred to the next level Some of the Energy is used in cell activities (growth, cell division), the rest is lost as heat

38. The Carbon Cycle: • An exchange of materials (carbon dioxide, oxygen) between autotrophs and heterotrophs

39. The Carbon Cycle:

40. Cycles in Nature: • Autotrophs: • use the sun’s energy to produce their own food in a process called photosynthesis • In photosynthesis CO2 is absorbed (taken in) from the environment and O2 (Oxygen) is released as a waste.

41. Cycles in Nature: • Heterotrophs: • take in the Oxygen and use it for cellular activities • Releases CO2 into the environment as a waste • The process is called cellular respiration

42. The Carbon Cycle: The Carbon Cycle is a balance between Carbon Dioxide and Oxygen in the air.

43. Remember… A population is a group of organisms of the same species living in a certain area

44. Discussion on Populations: • change over time • Most stabilize rather than continuously grow • As populations increase in #, it puts more demand on the resources available such as food, shelter, and water • Environmental factors that limit the size of a population are called limiting factors.

45. Limiting Factors: • Environmental factors that limit the size of a population • The availability of resources • Ex. Food, water, shelter, oxygen, sun

46. Density-Dependent Factors: • limit the growth of a population when the population reaches a certain size • Ex. Disease, competition, predators, and food • Population Density • The number of organisms in a given area • Predation, competition, and the spread of disease all are influenced by population density

48. Question: what happens to the level of competition when the population density increases? Predation? Disease?

49. Population Cont. • predator- prey population cycles