Presentation on theme: "Food Chains, Food Webs, and the Transfer of Energy"— Presentation transcript:
1 Food Chains, Food Webs, and the Transfer of Energy Symbiosis and Succession too!
2 AutotrophsA groups of organisms that can use the energy in sunlight to convert water and carbon dioxide into Glucose (food)Autotrophs are also called Producers because they produce all of the food that heterotrophs useWithout autotrophs, there would be no life on this planetEx. Plants and Algae
10 Heterotrophs Consumers 4. Omnivores – eat BOTH plants and animals Ex. – Bears and Humans
11 Heterotrophs Consumers 5. Decomposers – absorb any dead material and break it down into simple nutrients or fertilizersEx. – Bacteria and Mushrooms
12 Transfer of EnergyWhen a zebra eats the grass, it does not obtain all of the energy the grass has (much of it is not eaten)When a lion eats a zebra, it does not get all of the energy from the zebra (much of it is lost as heat)
13 Transfer of EnergyThe two (2) previous examples of energy transfer show that no organism EVER receives all of the energy from the organism they just ateOnly 10% of the energy from one trophic level is transferred to the next – this is called the 10% law
14 Trophic LevelsEnergy moves from one organisms to another when it is eatenEach step in this transfer of energy is know as a trophic levelThe main trophic levels are producers, consumers, and decomposers
15 Food ChainsThe energy flow from one trophic level to the other is know as a food chainA food chain is simple and directIt involves one organism at each trophic levelPrimary Consumers – eat autotrophs (producers)Secondary Consumers – eat the primary consumersTertiary Consumers – eat the secondary consumersDecomposers – bacteria and fungi that break down dead organisms and recycle the material back into the environment
21 BiomassThe total mass of the organic matter at each trophic level is called biomassBiomass is just another term for potential energy – energy that is to be eaten and used.The transfer of energy from one level to another is very inefficient (10% Law)
23 Ecological PyramidAn ecological pyramid shows the relationship between consumers and producers at different trophic levels in an ecosystemShows the relative amounts of energy or matter contained at each trophic levelThe Pyramid shows which level has the most energy and the highest number of organisms
26 Ecological Pyramid Which level has the most energy? Which level has the most organisms?Which level has the least organisms?Which level has the least energy?
27 SymbiosisA close and permanent association between organisms of different speciesMutualism – a relationship in which both organisms benefit from each otherExample: Birds eating pest off a rhino’s backCommensalism – a relationship in which one organism benefits and the other is not affectedExample: Barnacles on a whaleParasitism – A relationship in which one organism benefits and the other is harmedExample: Ticks on a dog
28 In your Lab notebook complete the following: Symbiotic RelationshipTextbook DefinitionMy definition (less than 4 words)My exampleCommensalisma relationship in which one organism benefits and the other is not affectedMutualisma relationship in which both organisms benefit from each otherParasitismA relationship in which one organism benefits and the other is harmed
29 Ecological Succession: Some Definitions the gradual and directional process of species change in a communitybiotic communities change through time in response to many influences:climatic changedisturbancesinvasion of species from other areasEventually, succession leads to a climax community
30 Primary Successionthe processes and progress involved in changing an area from one lacking any community (no plants, no animals, no insects, no seeds, etc.) to one consisting of individuals, populations, communities, and ecosystems.the arrival of life in an area where no community previously existed.
32 Secondary SuccessionThe arrival of new species in an area that already has life.Results in the transition of a community from pioneer species to climax species.Because soil may already be present, the rate of secondary succession is faster than primary succession.Secondary succession also indicates changes in community composition following disturbances.
33 Example of Secondary Succession This is an example of a secondary succession following a disturbance (fire). It does not completely wipe out life.
34 What is a Pioneer Species? The first species to colonize an area (usually lichens and mosses but sometimes higher plants), beginning the process of soil formation.
35 What is Climax Community? A community that remains fairly constant in species composition if the land and climate are undisturbed. These are the communities that characterize the various biomes.
36 A summary of changes that occur during succession: Pioneer species colonize a bare or disturbed site. Soil building.Changes in the physical environment occur (e.g., light, moisture).New species of plants displace existing plants because their seedlings are better able to become established in the changed environment.Newly arriving species alter the physical conditions, often in ways that enable other species to become established.Animals come in with or after the plants they need to survive.Eventually a climax community that is more or less stable will become established and have the ability to reproduce itself.Disturbances will start the process of succession again.
37 “Food Web of Biome_____” this is your title Choose a Biome from pg ) to draw a food webDraw, Color and Label your Food WebExample on pg 71A food web shows how two or more food chains interactMust show arrows showing energy flowWhat eats what4. Must label organisms as:Method of nutritionProducerHerbivoreCarnivoreOmnivoreTropic Level1st Consumer2nd Consumer3rd ConsumerDecomposer or ScavengerDon’t forget about the SUN!