2. Ecology

3. The study of interactions between organisms & their environment

4. Biotic factors Living, or once living, organisms in an environment

5. Abiotic factors Non-living parts of an environment Air Water Temperature Light Soil Salinity

6. Ecological levels of organization (Smallest to Largest) Organism – a single member of a species Population – a group of interbreeding organisms of the same species which live in the same habitat Competition for food, water, mates, shelter, etc… due to lack of resources

7. Ecological levels of organization (Smallest to Largest) Biological community – Interacting populations in the same habitat Population changes can affect each other in a community

9. Ecological levels of organization (Smallest to Largest) Ecosystem – Plant & animal populations interact with each other & the abiotic factors in an environment 1. Terrestrial ecosystems 2. Aquatic ecosystems

10. Ecological levels of organization (Smallest to Largest) Biosphere – All ecosystems interacting on Earth

11. Organisms in ecosystems Habitat – place an organism lives out its life Niche – the job or role of an organism in its environment 1. How does it meet needs for food? 2. Shelter 3. How and where it survives 4. Reproduction

12. Symbiosis (living together) A close and permanent relationship between organisms of different species 3 Types Mutualism Commensalism Parasitism

13. Mutualism A symbiotic relationship where both species benefit e.g. 1. Clown fish and sea anemone 2. Humans and pets 3. Ants & Peony flowers 4. Lichens – algae and a fungus

14. British Soldier Lichen

16. Commensalism A symbiotic relationship in which one species benefits and the other is neither helped nor harmed e.g. Epiphytes and trees (Epiphytes grow in the tree {habitat}, but the tree does not benefit nor is it harmed) Egret sitting on a rhino Barnacle on a whale

18. Parasitism A symbiotic relationship where one organism benefits and the other is harmed e.g. 1. Dog and tick 2. Brown headed cowbird and other passerines

20. What type of symbiosis?

21. Energy flow in an ecosystem

22. Producers (Autotrophs) – obtain energy from the sun via photosynthesis Consumers (Heterotrophs) – obtain energy by eating producers or other consumers

23. Types of consumers Primary consumer – eats producers Herbivores – eat only producers Detritivores- eat detritus (or humus) dead decaying organic material Secondary consumer – eats primary or other secondary consumers a. Carnivore – eat other consumers b. Omnivore eats both consumers and producers c. Scavenger – eat animals that have already died d. Decomposers – break down dead organisms

24. Energy flow in an ecosystem Food chain – model used by scientists to show the flow of energy in an ecosystem Food web – model used by scientists to show all the possible feeding relationships at each trophic level in a community

27. Energy flow in an ecosystem Pyramid of Energy – 90% of energy lost in each trophic level 100% Producers get 100% of energy available 10% Primary consumers get 10% of energy available 1% Secondary consumers get 1% of energy available 0.1% Tertiary consumers get 0.1% of energy available

31. Energy flow in an ecosystem Pyramid of Numbers – Population size should decrease at each higher trophic level 3000 Grasses support 250 grasshoppers which support 25 birds which support 1 fox

32. A = plankton, B = shrimp, C = fish, D = seagull The pyramid below is a way of showing how the numbers of organisms decrease along the food chain, finishing with the top carnivore at the apex.

33. Energy flow in an ecosystem Pyramid of Biomass – total mass of living matter at each trophic level 100 kg of grain is needed to support 10 kg of beef which supports 1 kg of human tissue

36. Cycles in Nature Water Carbon Nitrogen Phosphorus

37. Water cycle Evaporation Transpiration Condensation Precipitation Runoff Infiltration

39. Carbon Cycle Atmospheric CO 2 (burning, fuel combustion, respiration) Death & decay result in fossil fuel formation Photosynthesis (CO 2 conversion into glucose) Biomass – storage of carbon as coarse woody debris

40. Carbon Cycle

41. Nitrogen Cycle Atmospheric Nitrogen fixation by plants, bacteria, & lightning Urine (From protein catabolism) Fecal matter & fertilizers Dead & Decaying plant or animal matter Nitrogen evaporates into atmosphere from ground (Due to denitrifying bacteria)

42. Nitrogen Cycle

43. Phosphorus Cycle Plants obtain phosphorus from soil Animals obtain phosphorus by eating plants Animals die and decomposers break down phosphorus compounds and phosphorus returns to the soil (phosphates)

44. Phosphorus Cycle