Intro to Ecology Notes

1. Intro to Ecology Notes QQ#1: What is Ecology?

2. What is Ecology? • The study of interactions among organisms and between organism and their environment, or surroundings. • Basically… • Why animals are where they are and how they interact.

3. Levels of Organization • To understand these relationships within the biosphere, scientists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere. QQ#2: What is a species?

4. Levels of Organization • Species: a group of organisms so similar to one another that they can breed and produce fertile offspring

5. Levels of Organization • Populations: Groups of individual of the same species that live in the same area

6. Levels of Organization • Communities: two or more populations that live in a defined area. QQ#3: What is an ecosystem?

7. Levels of Organization • Ecosystems: collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment

8. Levels of Organization • Biome: group of ecosystems that have the same climate and similar dominant communities

9. What Shapes an Ecosystem? Biotic and Abiotic Factors Niche Community Interactions Successions

10. Biotic and Abiotic Factors • Biotic factors: • Biological influences on organisms within an ecosystem • Living or once-living • Abiotic Factors: • physical factors that shape an ecosystem • Non-living BIOTIC ABIOTIC QQ#4: What are some examples of biotic factors? abiotic factors?

11. Biotic and Abiotic Factors • Examples of Abiotic Factors: •Temperature •Water •Sunlight •Salinity - amount of dissolved salt •Wind, rocks and soil •Catastrophes - earthquakes, fires, floods, landslides, toxic spills • Examples of Biotic factors: • Plants and animals • Aquatic (water) • Benthic (bottom-dwelling) • Terrestrial (land)

12. Biotic and Abiotic Factors • Biotic and abiotic factors determine the growth and survival of an organism • Also determine the productivity of the ecosystem in which an organism lives • Habitat: area where an organisms lives (biotic and abiotic included)

13. Niche • Niche: the full range of physical and biological conditions in which an organism lives and the way the organism uses those conditions. • Place in the food web • Food it eats, how it obtains it, etc. • Physical conditions needed to survive • Temperatures it can survive in

14. Niche • No two species can share the same niche in the same habitat. • Can occupy different niches that are very similar.

15. Community Interactions • Organisms that live together in ecological communities constantly interact. • Competition • Predation • Symbiosis • All affect an ecosystem

16. Competition • Occurs when organisms of the same or different species attempt to use a resource at the same place and time. • Resource: any necessity of life (water, food, light, space, etc.)

17. Competition • Direct competition • Results in a winner and a loser • Losing organism fails to survive.

18. QQ#5 • A bear catches and eats a fish for food. • Who benefits? • Who doesn’t?

19. Predation • An interaction in which one organism captures and feeds on another organism • Predator: the one that does the killing/eating • Prey: the one being eaten

20. Symbiosis • Any relationship in which two organisms live closely together • Means “living together” • 3 Main classes in nature: • Mutualism • Commensalism • Parasitism

21. QQ#6 • The ant cares for the aphids and protects them from predators. The aphids produce a sweet liquid that the ant drinks. • Who benefits? Who doesn’t?

22. Mutualism • Both species benefit from the relationship Bee and Flower Clownfish and Sea Anemone

23. QQ#7 • The orchid benefits from its perch in the tree as it absorbs water and minerals from rainwater and runoff. • Who benefits? Who doesn’t?

24. Commensalism • One member in the relationship benefits, while the other is neither helped nor harmed. Barnacles and Whales

25. QQ#8 • A tick feeds on the blood of its host and may also carry disease-causing microorganisms. • Who benefits? Who doesn’t?

26. Parasitism • One organism lives on or inside another organisms and harms it. • Parasite obtains all or part of its nutritional needs from the host • Generally weakens but does not kill their host a tomato hornworm is covered with cocoons of pupating braconid wasp

27. Ecological Succession • Ecosystems are constantly changing due to natural or human disturbances. • Older inhabitants gradually die out and new organisms move in, causing changes in the community.

28. Ecological Succession • Ecological Succession: series of predictable changes that occur in a community over time. • Succession may result from: • Slow changes in physical environment • Sudden disturbance from human activities

29. Primary Succession • Occurs on surface where no soil exists. • Where lava rock is from volcanic explosion • On rock exposed when glaciers melt

30. Primary Succession • Pioneer species: first species to populate the area • On volcanic rock, often lichens (fungus and aglae that can grow on bare rock) • When they die, add organic material to help form soil for plants to grow.

31. Secondary Succession • When the natural or human disturbance is over, community interactions tend to restore the ecosystem to its original conditions.

32. Succession in a Marine Ecosystem • Occurs when a large whale dies and sinks to the bottom. • Attracts scavengers and decomposers. • Decomposition of body enriches surrounding sediments. • Heterotrophic bacteria decompose oils in bone that release chemical compounds that serve as energy sources.