Ecology. The scientific study of the interactions between organisms and their environments (abiotic and biotic).

Transcription

1 Community Ecology

2 Ecology The scientific study of the interactions between organisms and their environments (abiotic and biotic). 1. Abiotic: non-living factors (temperature, light, water, and nutrients) 2. Biotic: living factors living factors (other plants and animals)

3 Hierarchy of Organization Biological organization: Based on structural levels from Least to Most Inclusive. 1. Atoms 2. Molecules 3. Organelles 4. Cells 5. Tissues 6. Organs 7. organs systems The Realm Of Ecology

4 8. Organisms Individuals (species) composed of many specialized cells.

5 9. Populations Localized groups of organisms belonging to the same species. Groups of individuals of the same species living together.

6 10. Community Populations of organisms living together in the same environment. Four properties: 1. Diversity 2. Prevalent form of vegetation 3. Stability (resist change) 4. Trophic structure (feeding structure)

7 11. Ecosystem Dynamic system of organisms interacting with each other (biotic) and the inanimate environment (abiotic).

8 12. Biomes Broad geographic region with a characteristic array of organisms. Examples: 1. Tropical rain forest 2. Desert 3. Chaparral 4. Estuaries 5. Coral reefs

9 13. Biosphere Entire surface of the earth and its organisms.

10 Habitat The place or region where an organism lives.

11 Ecological Niche An organisms habitat, role, resource requirements, and tolerance ranges for each abiotic condition.

12 Competition A form of interaction in which two or more individuals or species utilize the same limited resources. Two examples: 1. Intraspecific competition 2. Interspecific competition

13 1. Intraspecific Competition Competition within a species for the same limited resources in the same habitat.

14 2. Interspecific Competition Competition between two or more species for the same limited resources in the same habitat.

15 Competitive Exclusion Principle States the following: 1. The concept that two species cannot continue to occupy the same environmental niche. 2. They would compete for the same limited resources. 3. One species will use the resources more efficiently and have a reproductive advantage that will eventually lead to elimination of the other species.

16 Symbiosis A form of interspecific interaction in which a host species and symbiont maintain a close association. Example: 1. Predation

17 1. Predation Where one organism (the predator) acquires its needed resources by eating another organism (the prey). Predator/prey relationship. Example: lynx and snowshoe hare

18 Question: How do some organisms avoid becoming prey? Answers: 1. Camouflage 2. Aposematic 3. Mimicry

19 1. Camouflage Cryptic coloration: a. Hides from predators. b. Example: English Peppered Moth

20 2. Aposematic Bright colors a. Advertises noxious trait b. Example: Monarch Butterfly

21 3. Mimicry Two examples: 1. Mullerian Mimicry: when two unpalatable species mimic each other in the same habitat. 2. Batesian Mimicry: palatable species mimic unpalatable species.

22 Keystone Predator A predator the maintains species diversity in a community. Reduces the density of the strongest competitors in a community. Example: 1. Red-tailed hawk 2. Coyote 3. Harvester ant

23 Symbiotic Relationships Help structure communities. Three examples: 1. Parasitism 2. Commensalism 3. Mutualism

24 1. Parasitism Symbiotic relationship which benefits one organism and harms the other. Example: 1. Tick on a coyote 2. Tapeworm in a dog 3. Flea on a cat

25 2. Commensalism Symbiotic relationship which benefits one organism while the other is unaffected. Example: 1. Cattle egrets and cattle in field

26 3. Mutualism Symbiotic relationship which benefits both organisms. Examples: 1. Acacia ants and acacia tree 2. Termites and gut protozoa 3. Legumes and nitrogen-fixing bacteria

27 Ecological Succession Transition in species composition over ecological time. Three examples: 1. Primary Succession 2. Secondary Succession 3. Climax Community

28 1. Primary Succession Occurs in areas where no community existed before (first succession). Example: 1. New volcanic islands - lichens

29 2. Secondary Succession Occurs in disturbed habitats where some soil, and perhaps some organisms, still remain after the disturbance. Example: 1. Fires 2. Floods 3. Drought

30 3. Climax Community Community that remains essentially the same over long periods of time. It is the final stage of ecological succession.

31 Trophic Structure The different feeding relationships that determine the route of energy flow and the pattern of chemical cycling. According to the rules of ten, approximately 10% of the potential energy stored in the bonds of organic molecules at one trophic level fuels the growth and development of organisms at the next trophic level.

32 Trophic Structure Five examples: 1. Primary Producers 2. Primary Consumers 3. Secondary Consumers 4. Tertiary Consumers 5. Decomposers and Detrivores

33 1. Primary Producers Autotrophs: which make up the trophic level of an ecosystem that ultimately supports all other levels. Examples: 1. Mostly photosynthetic organisms

34 2. Primary Consumers Herbivores: organisms in the trophic level of an ecosystem that eat plants or algae. Examples: 1. Grasshopper 2. Mouse

35 3. Secondary Consumers The trophic level of an ecosystem consisting of carnivores that eat herbivores. Examples: 1. Snake 2. Green sunfish

36 4. Tertiary Consumers The trophic level of an ecosystem consisting carnivores that eat other carnivores. Examples: 1. Hawks 2. Mountain lions

37 5. Decomposers and Detrivores Heterotrophs that get their nutrition by breaking down the organic compounds found in waste organic matter and dead organisms.

38 5. Decomposers and Detrivores Examples: A. Decomposers: 1. Bacteria 2. Fungi B. Detrivores: 1. Worms 2. Nematodes 3. Insects 4. Lobsters 5. Shrimp 6. Condors

39 Trophic Structure Tertiary Consumer: snake (10( KCAL) Secondary Consumer: mouse (100( KCAL) Primary Consumer: grasshopper (1,000( KCAL) Primary Producers: grass (10,000( KCAL)

40 Food Chain The transfer of food from trophic level to trophic level. Example of a food chain: 1. Primary producer: 2. Primary consumer: 3. Secondary consumer: fish 4. Tertiary consumer: phytoplankton zooplankton fisherman 5. Quaternary consumer: shark

41 Food Web The map of all interconnections between food chains for an ecosystem.

42 Biomass The amount or mass of organic material in an ecosystem.

43 Primary Productivity Is the rate where solar energy is converted to the chemical energy of organic (glucose) compounds by autotrophs (plants). Net primary production equals photosynthesis - cellular respiration

44 Tropical Rain Forest Occur in equatorial areas High abundance of yearly rain (>250 cm a year in some areas) Has the highest number of different species per square mile.

45 Tropical Rain Forest Human impacts a great concern: 1. Clear cutting for wood and farmland. 2. May cause large scale changes in world climate. 3. There will be a large scale loss of species.

46 Negative Impacts to Ecosystems 1. Clear-cutting of forest upsets chemical cycling. 2. Eutrophication: increased mineral input which chokes aquatic life. 3. Environmental disasters: Valdez Oil Spill 4. Pollution: water, air (acid rain), pesticides and herbicides.