4 Biosphere Earth’s organisms live in the biosphere. The biosphere consists of the parts of the planet in which all life exists.Ecologists may study different levels of ecological organization:Individual organismAn assemblage of individuals that belong to the same species and live in the same area is called a population.An assemblage of different populations that live together in an area is referred to as a community.
6 EcosystemAn ecosystem includes all the organisms that live in a particular place, together with their physical environment.A group of ecosystems that have similar climates and organisms is called a biome.
7 BiomesA group of ecosystems that have similar climates and organisms is called a biome.ExamplesTropical Rain ForestDesertTemperate Forest ( we live here)
8 Biotic and Abiotic Factors Ecosystems include biotic and abiotic factors.A biotic factor is any living part of an environment.An abiotic factor is any nonliving part of an environment.
9 Ecological MethodsEcologists use three basic methods of research: observation, experimentation, and modeling:Observation often leads to questions and hypotheses.Experiments can be used to test hypotheses.Modeling helps ecologists understand complex processes.
10 3.2 Energy, Producers & Consumers Primary ProducersSunlight is the main energy source for life on Earth.Organisms that can capture energy from sunlight or chemicals and use that energy to produce food are called autotrophs, or primary producers.
11 Primary Producers = Autotrophs The process in which autotrophs capture light energy and use it to convert carbon dioxide and water into oxygen and sugars is called photosynthesis.The process in which autotrophs use chemical energy to produce carbohydrates is called chemosynthesis.
12 PhotoautotrophsWithout autotrophs, there would be no life on this planetEx. Plants and Algae
13 Autotrophs Chemotrophs Autotrophs that get their energy from inorganic substances, such as saltLive deep down in the ocean where there is no sunlightEx. Bacteria and Deep Sea Worms
14 Consumers = Heterotrophs Organisms that do not make their own foodAnother term for Heterotroph is consumer because they consume other organisms in order to liveEx. Rabbits, Deer, Mushrooms
18 Heterotrophs = Consumers Omnivores – eat BOTH plants and animalsEx. – Bears and HumansKyle Smith
19 Heterotrophs = Consumers Detritivores - feed on the tissue (detritus) of dead organisms (plant or animal)Shrimp, earthworms, dust mites
20 Heterotrophs = Consumers Decomposers – absorb any dead material and break it down into simple nutrients or fertilizersEx. – Bacteria and Mushrooms
21 Heterotrophs = Consumers Scavengers– Consumes the carcasses of dead animals but does not typically kill them itself.Ex. – Vultures & Crows
22 Energy Flow in Ecosystems (Transfer of Energy) When 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)
23 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
24 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
25 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
31 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)
33 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
34 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?