Ecology

1. Ecology • the study of _______ interact with each other and the environment

2. Energy • every organism belongs to a trophic level • trophic level: __________________ • food energy passes through an ecosystem from one trophic level to another

3. food web: __________path of energy

4. Food chain: ________path

5. Members of the food chain

6. 4. producers-consumers • Producers • __________________ energy: Autotrophs: • Plants • Algae • some bacteria • __________ trophic level of any ecosystem

7. consumers • Heterotrophs: obtain their energy by ____________ • Herbivores • primary consumers, second trophic level • eat producers • Carnivores • secondary consumers, third trophic level • eat hervibores or other carnivores • Omnivores • Eat some carnivores also eat plants • Decomposers • break down ________ making them available to other organisms • bacteria and fungi

8. RELATIONS-INTERACTIONS • Competition • Predator-prey • Symbiosis: • Parasitism • Comensalism • Mutualism • producers-consumers: • Herbivores • Carnivores • omnivores

9. 1.Competition • interaction when _________________________ when there is not enough of the resource to satisfy both: • interspecific competition: different species • intraspecific competition: same species

10. principle of competitive exclusion: Resource partitioning • two species competing for a resource, the species that uses the resource more efficiently will eventually ______the other locally • no two species with the same niche can coexist • natural selection favors changes to ________ the competition and niche overlap

11. 2. Predator-Prey • Predation is the consuming of one organism by another • essential factor in rich and diverse species because: • predators prevent/reduce competition by reducing the number of individuals of competing species • predators have large effects on prey populations: example “10-year cycle” of the snowshoe hare that appears to be under the influence of food plants and predators

12. 3.Symbiosis • interaction of two or more organisms: whether or not each participant is unaffected (0), helped (+), or harmed (-) • Commensalism (+,0) • Parasitism (+,-) • Mutualism (+,+)

13. Levels • Niche, organism’s biological role • Populations, individuals of the same species living together • Communities, populations of different species that live together in the same place • Ecosystems,a community and the nonliving factors which it interacts • Biomes,plants, animals, and microorganisms living over wide geographic areas and have distinctive physical characteristics • Biosphere,all the world’s biomes

14. 1. Niche • organism’s biological role: the sum of all the ways an organism uses the resources of its environment (space, food, and many other factors) The zebras fill a niche in this African savanna community

15. 2. Populations • Population: individuals of a species that live together: • Clumped • Uniform • random

16. Exponential/sigmoid growth curve: capacity for growth • competition and emigration increase as a population approaches its carrying capacity

17. 3. Communities • living part or species of an ecosystem • recognized by their most dominant species (usually a plant)

18. 4. Ecosystems • Dynamic and fundamental units of ecology • have limiting factors that affect diversity: • Energy • nutrients • environmental limiting factors diversity: • Rainfall • temperature

19. TYPES OF ECOSYSTEMS • Ocean • Freshwater • Land Ecosystems

20. Ocean Ecosystems • average depth more than 3 km • cold and dark, photosynthetic organisms confined to the upper few hundred meters • organisms that live below this level feed on organic debris from above

21. three main types of ocean ecosystems 1. shallow water • along the shoreline • contains the most species • part of this area 2. open-sea surface • contains a lot of phytoplankton that drift with the current and perform 40% of all the photosynthesis that takes place on earth 3. deep-sea water • Very few organisms live below 300 meters

22. Freshwater Ecosystems • include lakes, ponds, rivers, and wetlands • large amount of organic and inorganic material enters from nearby land

23. Ponds and lakes have three zones: • shallow “edge” • open-water surface • deep-water, no light

24. 5. Biomes: Land Ecosystems • seven major and seven minor biomes

25. Tropical rain forests: • richest ecosystems • Diverse communities

26. Savannas: • grasslands that have widely spaced trees and seasonal rainfall • transition between tropical rain forest and desert

27. Deserts: • dry places with sparse vegetation • Plants and animals may restrict their activity to favorable times of the year, when water is present

28. Grasslands: • also called prairies • in temperate areas • Most have been converted to use by agriculture

29. Deciduous forests: • trees that drop their leaves in the winter

30. Taiga: • coniferous trees • extends across vast areas of North America and Asia

31. Tundra: • open grassland • far north beyond the taiga • Permafrost, or permanent ice, usually exists within 1 meter of the surface

32. Chapparal: • evergreen, often spiny shrubs and low trees • dry summer climate, also known as Mediterranean

33. Polar ice caps • Arctic Ocean in the north and the Antarctica in the south • almost no precipitation and freshwater is scarce

34. Practice questions 1.The way a species makes its living, that is, the biological and physical conditions in which it exists, is called its ________ 2.In the levels of ecological organization, the lowest level, composed of individuals of a single species who live near each other, share the same resources, and can potentially interbreed is called a ___________ 4. A major principle of ecology states that “no two species can occupy exactly the same niche. One will utilize the resource more efficiently than the other and will drive the second species to extinction” This is the principle of __________

35. 5. The following are examples of symbiosis except: A)Mutualism B)predation C)parasitism D)commensalism 6.Energy from light is converted into chemical energy for organisms by ________ 8. The number of carnivores found at the top of an ecological pyramid is limited by: • number of organisms below • number of trophic levels below • amount of biomass below • amount of energy transferred to the top carnivores

36. 13. When the number of organisms remains more or less the same over time in the specific place where these organisms live, it is said that this population of organisms has reached the _____ ____of that place. 14. All the animals and plants that live in the same location make up a ___ 15. For similar species to occupy the same space, their niches must be different in some way. One way for these species to both survive is ___ ____ 16. A relationship between two species where one species benefits (+) and the other is neither hurt nor helped (0) is known as _________ 17. Predators can assist in maintaining the species diversity of an area by: • increasing competitive exclusion between prey species • decreasing competitive exclusion between prey species • not affecting competitive exclusion between prey species