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Ecology Slide 2 Ecology is the study of the interactions among organisms and their environment Slide 3 What is the Biosphere? The portion of the earth in which all living things exist Only about 20Km of total diameter of earth From ocean floor to about 8Km above earths surface Slide 4 Two types of factors in Biosphere Biotic: all things living Examples? Abiotic: all things non-living Examples? Slide 5 Many subcategories Population: all individuals of a certain species within a certain area Community: all the populations of different species within an area Slide 6 Many subcategories Ecosystem: includes a community and its physical environment Includes both biotic and abiotic Slide 7 Slide 8 Individuals have a habitat and a niche Habitat: where an individual organism lives; its home where is yours? Niche: the role that organism plays in its ecosystem What is yours? Slide 9 Relationships between organisms Competition: if two individuals occupy the same niche they will compete Limited resources like? Only one will win Slide 10 Relationships between organisms Symbiosis: two organisms living in close association Three types: mutualism, commensalism and parasitism Slide 11 Relationships between organisms Mutualism: both species benefit Example? Why? Slide 12 Commensalism: one benefits; the other is neither hurt nor helped Relationships between organisms Slide 13 Parasitism: one species benefits at the others expense Relationships between organisms Slide 14 All organisms require Energy As one organism eats another energy moves through ecosystem Forms food chain Many food chains make food web Slide 15 Food Chain Slide 16 Food Web Slide 17 Mother Nature Recycles All essential inorganic nutrients cycle between biotic and abiotic parts of ecosystem - Water - Oxygen - Carbon - Phosphorus - Nitrogen Slide 18 Water Cycle Slide 19 Organisms give off water Water evaporates into atmosphere Water condenses in cloud Falls back to earth in rain/snow Taken back in by Organisms Slide 20 Carbon cycle Slide 21 Nitrogen Cycle Slide 22 Phosphorous Cycle Slide 23 Oxygen Cycle Slide 24 Energy Pyramid Slide 25 Producers/Autotrophs: make food from sunlight or other inorganic molecules examples: plants, algae and bacteria Slide 26 Energy Pyramid Primary consumers: eat producers Herbivores Examples: rabbits, plankton Slide 27 Energy Pyramid Secondary or High order consumers: eat primary consumers carnivores Larger animals Top consumers are not eaten by anyone Slide 28 Where do they go then ? Decomposers: bacteria; break down dead organisms and return nutrients (nitrogen) back to the soil for producers to use Slide 29 Biomes Large groups of ecosystems all with a similar climate Distributed across earth by large shifting blocks of land called tectonic plates Slide 30 Shifting Land Sea Floor Spreading Slide 31 As land shifts so does sun exposure, temperature and rainfall Explains the different climates in different biomes Slide 32 Slide 33 Succession the changes an ecosystem goes through over time A kind of evolution (simple complex!) Slide 34 Primary Succession Begins with rocks Pioneer species: Moss and Lichens Slide 35 Primary Succession Primary succession begins in barren areas, such as the bare rock exposed by a retreating glacier. First inhabitants are PIONEER SPECIES lichens or mosses grown on bare rock convert the rock into soil that can support simple plants such as grasses. GRASSES : further modify the soil, which is then colonized by other types of plants. Each successive stage modifies the habitat by altering the amount of shade and soil composition. CLIMAX COMMUNITY: Stable final stage that can endure for hundreds of years.. Slide 36 Secondary Succession Occurs after a disturbance Slide 37 Secondary Succession After a major disturbance, fire or flood. Farmland that has been plowed Secondary succession is similar to primary succession one important difference: primary succession always begins on a barren surface, secondary succession begins in an area that already has soil. Slide 38 Climax community is the goal, but is rarely reached Disturbances can set the ecosystem back Fires, logging, flood,etc. Slide 39 Climax community Slide 40 Limits to an Ecosystem Slide 41 Thomas Malthus Plants and animals produce far more offspring than can survive, Man too is capable of overproducing if left unchecked. Unless family size was regulated, man's misery of famine would become globally epidemic and eventually consume Man. Slide 42 Carrying Capacity An ecosystem has only enough resources to support a certain number of organisms This number is the ecosystems Carrying Capacity Non-renewable resources Renewable resources Slide 43 CC controlled by competition immigration emigration catastrophic events seasonal fluctuations in food, water (available resources) hiding places, and nesting sites (shelter and family homes Population Densities Slide 44 Stable or Not? Slide 45 STABLE! There will always be fluctuations around the average Slide 46 What happens as we approach the carrying capacity? Slide 47 Competition Survival of the fittest Numbers cannot go higher because there are limited resources. If an invasive species is present, could result in extinction or severe lowering in the numbers of other species due to lack of predators for the invasive species!