ECOLOGY

1. ECOLOGY BIO.B.4

2. Ecology • Ecology – the study of interactions among and between organisms and their environment

3. Organizational Groups • Levels of Organization (small to large) • Species – group of organisms that can breed and produce fertile offspring • Populations – groups of the same species that live in the same area • Communities – groups of different populations (therefore different species) that live in the same area

4. Ecosystem – all of the organisms that live in a particular place, together with their nonliving environment • Biome – a group of ecosystems that have the same climate and similar dominant communities • Examples: • Biosphere – part of Earth in which life exists including land, water, and air.

5. Ecological Levels of Organization

6. The World’s Major Land Biomes

7. Energy Flow Through An Ecosystem • Sunlight is the main source of energy for life on Earth. • Less than one percent of the sun’s energy that reaches the surface is used by living thing • Autotrophs (producers) – organisms that use either light energy or inorganic chemicals make their own food

8. Photosynthesis – process in which organisms use light to make their own food (sugar) • Examples: plants, algae, some bacteria and some protists • Chemosynthesis - process in which organisms use inorganic chemicals to makefood • Examples: bacteria which live in volcanoes, hot springs, and deep-sea vents

9. Heterotrophs (consumers) – organisms that must eat food for their energy and cannot make their own food • Herbivores – eat mostly plants • Examples • Carnivores – eat mostly animals • Examples • Omnivores – eat both plants and animals • Examples • Decomposers – break down organic material • Examples

10. Feeding Relationships • Food Chain – series of steps in which organisms transfer energy by eating or being eaten • Food web – links all of the food chains in an ecosystem • Trophic Level – each step in a food chain or food web

11. What eats what? This is the order that energy flows through an ecosystem: • Producers • Primary (first) consumers • Secondary (second) consumers • Tertiary (third) consumers • Arrows point the direction the energy or food flows (from food to “eater”).

12. A Food Web Section 3-2 Make your own food web

13. Energy Pyramid • Energy Pyramid - shows the relative amount of energy available at each trophic level.

14. Ten Percent Rule - only about 10% of energy available within one trophic level is transferred to next level • Why this inefficiency? • Most of the energy that an organism uses does not make it into the organism that eats it. • Energy in feces, energy used in metabolism, and energy converted to heat does not make it to the next trophic level.

15. Not all of the caterpillar’s food is converted into biomass or potential energy for a predator. So the bird that eats this caterpillar will not get energy from the caterpillar’s feces, or the energy that was used by the caterpillar.

16. Ecological Terms • Biotic – biological (living) factors that affect an ecosystem • Abiotic– nonliving (physical) factors that affect an ecosystem

17. Abiotic and Biotic Factors Section 4-2 Abiotic Factors Biotic Factors ECOSYSTEM Go to Section:

18. Abiotic and Biotic Factors Section 4-2 Abiotic Factors Biotic Factors ECOSYSTEM Go to Section:

19. Niche – full range of physical and biological conditions in which an organism lives and the way the organisms uses those conditions

20. Figure 4-5 Three Species of Warblers and Their Niches Section 4-2 Cape May Warbler Feeds at the tips of branches near the top of the tree Bay-Breasted Warbler Feeds in the middle part of the tree Yellow-Rumped Warbler Feeds in the lower part of the tree and at the bases of the middle branches Spruce tree Go to Section:

21. Interactions in Ecosystems Section 4-2 • Organisms not only live together in ecological communities, but they also constantly interact with one another. These interactions, which include predation and competition, help shape the ecosystem in which they live.

22. Community Interactions • Competition—an interaction in which organisms of the same or different species attempt to use a resource in the same place and at the same time. • Predation—an interaction in which one organism captures and feeds on another animal

23. Symbiosis– a relationship in which two species live closely together • Three types of symbiosis: • Mutualism= + + (both benefit) • Examples: • Commensalism= + 0 (one benefits, other little or no benefit) • Examples: • Parasitism= + - (one benefits, other harmed) • Examples:

24. Termites have bacteria in their guts that help the termites to digest wood. The bacteria get a nice, warm gut in which they can live. What relationship is this?

25. Some orchids grow on trees to get sunlight in dark forests. The orchid does not hurt the tree. What relationship is this?

26. Remora attach to big fish or whales and eat the parasites that grow on the big fish’s or whales scales. What relationship is this? Remora Remora attached to a big fish

27. The hookworm latches on the walls of the colon with its sharp teeth where it feeds on blood. The tapeworm is the longest parasite. A mature adult can lay one million eggs per day. Tapeworm eggs are embedded in the colon. The roundworm can grow to 20 inches (50 cm) long and lay 200,000 eggs per day. Pinworms migrate outside the colon during the night to lay their eggs around the anus. This causes the nightly itching of many unsuspecting victims.

28. Ticks suck the blood of animals (including people). What relationship is this?

29. Mouth of a hookworm Hookworms live in the intestines of many mammals including humans. They suck blood from your gut and can make you sick. What relationship is this?

30. Ringworm (top left and bottom right) and athlete’s foot (top right) are both fungi that live off of human skin. They both cause irritation and are very contagious. What relationships are these?

31. Pseudoscorpions hitching ride on a fly’s leg, Costa Rica. Pseudoscorpions, tiny relatives of true scorpions, often engage in the practice of phoresy, or hitchhiking. What relationship is this?

32. The anemonefish lives among the forest of tentacles of an anemone and is protected from potential predators not immune to the sting of the anemone. The anemonefish is protected from the sting of the anomone tentacles by a substance contained in the mucous on its skin. Some consider this relationship to be a case of mutualism, claiming that the anemonefish chases away other fish that might prey on the anemone. However this aspect of the relationship is not well documented.

33. Cycles of matter • Unlike the one-way flow of energy, matter is recycled within and among ecosystems • Biogeochemical cycles pass molecules around again and again • The Cycles • Water Cycle • Carbon Cycle • Nitrogen Cycle • Phosphorus Cycle

34. The Nitrogen Cycle Go to Section:

35. The Nitrogen Cycle • All living things need nitrogen as a nutrient. • Nitrogen gas makes up 78% of our atmosphere and yet animals and plants cannot use nitrogen gas as a nutrient. So what’s an animal or plant to do? • How do animals get nitrogen? They eat protein! • How do plants get nitrogen? From bacteria that are in the soil or in the roots of some plants. • Plants can only use nitrogen when it is in the form of nitrate (NO3-) or nitrite (NO2-).

36. Decomposers breakdown organic material (e.g. dead plants and animals) in the soil. Nitrogen comes from broken down proteins and DNA. • Some bacteria live in the soil and help to convert nitrogen into usable forms for plants. Plants absorb this useable nitrogen from the soil into their roots.

37. Nitrogen Fixation – when nitrogen gas is converted into useable nitrogen by bacteria • Some bacteria actually live inside of the roots of certain plants (like legumes) and can fix nitrogen in the roots. • This is like the bacteria that live in our guts and help us to digest food. • Legumes include peas, beans, peanuts, soybeans, alfalfa, and clover. • So how is this a cycle? Denitrification – some bacteria can convert nitrites back into nitrogen gas which is released into the atmosphere

38. Root Nodules

39. “Green Manure” – when farmers plant legumes and then plow them into the ground instead of harvesting the crop • The legumes release nitrogen fixing bacteria into the soil to help the next round of crops get their nitrogen.

40. Mount Saint Helens • At 8:32 Sunday morning, May 18, 1980, Mount St. Helens erupted. • Shaken by an earthquake measuring 5.1 on the Richter scale, the north face of this tall symmetrical mountain collapsed in a massive rock debris avalanche. Nearly 230 square miles of forest was blown over or left dead and standing. At the same time a mushroom-shaped column of ash rose thousands of feet skyward and drifted downwind, turning day into night as dark, gray ash fell over eastern Washington and beyond. The eruption lasted 9 hours, but Mount St. Helens and the surrounding landscape were dramatically changed within moments.

41. Harry Truman (not the president)

43. BEFORE

44. AFTER

45. AFTER BEFORE

46. Some weedy plants recover quickly

47. Forest blown over

48. Same forest 9 years later

49. Same forest 14 years later

50. Changes in an Ecosystem • Ecological Succession– a series of changes in a community over time in response to natural and human disturbances • As changes occur, older inhabitants die out and new organisms move in. • Primary Succession • Occurs where there is no soil • After a volcanic eruption • Bare rock exposed by glaciers moving