Presentation on theme: "KEY CONCEPT Life in an ecosystem requires a source of energy."— Presentation transcript:
1 KEY CONCEPT Life in an ecosystem requires a source of energy.
2 What have we learned about the relationship between predators and prey? Advantages:provides food for predatorspredators keep prey populations at just the right number so prey doesn't overcrowd and area and throw the ecosystem offthe constant need for evolution to better the chances of prey living and to better the chances of predators catching preyDisadvantages:non native introduction of predators or the introduction of more can wipe out prey species
5 An “Ecological System?” In the discipline of ecology, the wordEcosystem is an abbreviation of the term,ecological system – the basic unit in ecology..Sir Arthur Tansley ( )
6 An “Ecological System?” Components of an Ecosystem: Water Species Biotic Components and Abiotic (non-living)Sir Arthur Tansley ( )Physical ComponentsSpeciesPopulationsCommunitiesCompetition and PredationWaterNutrientsTopographyWeatherDisturbances
7 What Keeps Us and Other Organisms Alive? One-way flow of high-quality energy from the sun (returned as low quality heat)Cycling of matter or nutrients through parts of the biosphere (closed system applies; law of conservation of matter; time frame of seconds to centuries)Gravity (maintains atmosphere, enables movement & cycling of air, water, nutrients)
8 Energy and the Laws of Thermodynamics 20.1 – The Laws of Thermodynamics Govern Energy Flow.Energy exists in many forms, such as heat, light, chemical energy, and electrical energy. Energy is the ability to bring about change or to do work. Thermodynamics is the study of energy.KineticenergyEntropyEntropyPotentialenergy
9 Energy and the Laws of Thermodynamics The 1st Law of Thermodynamics: Energy can be changed from one form to another, but it cannot be created or destroyed.The total amount of energy and matter in the Universe remains constant, merely changing from one form to another.Isaac Newton ( )
11 Energy and the Laws of Thermodynamics The 2nd Law of Thermodynamics: "in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state." In energy transfer, some energy will dissipate as heat. The flow of energy maintains order of life.Isaac Newton ( )
12 - Scientists have studied many ecosystems and have concluded that this energy loss is a constant pattern. In fact, scientists have calculated that the percentage (%) of usable energy transferred from one organism to another is 10%.!! – That means that 90% of energy is lost as heat!!!So…. if producers captured 10,000 calories from the sun, then only bout 1,000 calories will be available to support primary consumers (herbivores), and only about 100 calories to support secondary consumers (carnivores or omnivores).
13 10% LAW.. !!In the Arctic, Eskimos hunt whales for food. Whales eat tons and tons of microscopic plankton. This plankton in turn eats microscopic algae.It requires 1,000 units of energy (calories) of algae to produce 100 calories of plankton which is what a whale uses to produce 10 calories of blubber (fat) to its body.Finally these 10 calories of whale blubber contains enough energy to give the Eskimo one calorie of energy.
14 Producers provide energy for other organisms in an ecosystem Producers provide energy for other organisms in an ecosystem. Name three producers.Producers get their energy from non-living resources.Producers are also called autotrophs because they make their own food.
15 Producers provide energy for other organisms in an ecosystem. Consumers are organisms that get their energy by eating other living or once-living resources. Name 3 consumers.Consumers are also called heterotrophs because they feed off of different things.
16 Photosynthesis in most producers uses sunlight as an energy source. Almost all producers obtain energy from sunlight. If the producer doesn’t use sunlight, what might they use?Photosynthesis in most producers uses sunlight as an energy source.Chemosynthesis in prokaryote producers uses chemicals as an energy source.carbon dioxide + water +hydrogen sulfide + oxygensugar + sulfuric acid
17 KEY CONCEPT Food chains and food webs model the flow of energy in an ecosystem.
18 A food chain links species by their feeding relationships. A food chain is a model that shows a sequence of feeding relationships. Why does “chain” fit this idea?A food chain links species by their feeding relationships.A food chain follows the connection between one producer and a single chain of consumers within an ecosystem.DESERT COTTONTAILGRAMA GRASSHARRIS’S HAWK
19 Create your own food chain Beginning with a producer and including at least three organisms, give an example of a food chain.
20 Consumers are not all alike. Herbivores eat only plants. Carnivores eat only animals.Omnivores eat both plants and animals.Detritivores eat dead organic matter.Decomposers are detritivores that break down organic matter into simpler compounds.carnivoredecomposer
21 Specialists are consumers that primarily eat one specific organism or a very small number of organisms. What other kinds of “specialists” do you know?Generalists are consumers that have a varying diet.
22 Trophic levels are the nourishment levels in a food chain. Primary consumers are herbivores that eat producers.Secondary consumers are carnivores that eat herbivores. Name one example.Tertiary consumers are carnivores that eat secondary consumers. Name one example.Omnivores, such as humans that eat both plants and animals, may be listed at different trophic levels in different food chains.
23 A food web shows a complex network of feeding relationships. An organism may have multiple feeding relationships in an ecosystem. Give an example.A food web emphasizes complicated feeding relationships and energy flow in an ecosystem.
24 A food web shows a complex network of feeding relationships.
26 Trophic Level = Feeding Level Trophic LevelsProducers energy10 consumer energy20 energy- Just like a skyscraper has floors, or levels, an energy Pyramid has distinct levels, called TROPHIC LEVELS.
27 1st Trophic Level2nd Trophic Level3rd Trophic Level4th Tr. Leveleskimos1 calorie10 calorieswhales100 caloriesplankton1000 caloriesalgaeA healthy ecosystem will always have the most energy available in the first trophic level.
28 Ecosystem Energetics- Energy Decreases in Each Successive Trophic Level.
30 Ecological pyramidsThe standing crop, productivity, number of organisms, etc. of an ecosystem can be conveniently depicted using “pyramids”, where the size of each compartment represents the amount of the item in each trophic level of a food chain.producersherbivorescarnivoresNote that the complexities of the interactions in a food web are not shown in a pyramid; but, pyramids are often useful conceptual devices--they give one a sense of the overall form of the trophic structure of an ecosystem.
31 Pyramid of energyA pyramid of energy depicts the energy flow, or productivity, of each trophic level.Due to the Laws of Thermodynamics, each higher level must be smaller than lower levels, due to loss of some energy as heat (via respiration) within each level.producersherbivorescarnivores
32 Pyramids of Energy Suggests: The number of trophic levels are limited. At each trophic level, there is a dramatic reduction in energy.Eating at lower trophic levels means more resources available.Movement up the pyramid explains the problems of Biological Magnification (DDT, PCBs, etc.)
34 REVIEW: What are Food Chains and Food Webs How energy moves in an ecosystemORwho eats who!? ;)
35 What is a Food Chain?Food Chain: A food chain shows one path of how energy moves through an ecosystemWhat is a Food Web?Food Web: A food web shows many paths of how energy moves through an ecosystem. A food web is made up of many different food chains.
38 Primary productivityPrimary productivity is the rate of energy capture by producers.= the amount of new biomass of producers, per unit time and space
39 Gross primary production (GPP) = total amount of energy capturedNet primary production (NPP)= GPP - respirationNet primary production is thus the amount of energy stored by the producers and potentially available to consumers and decomposers.
40 Secondary productivity is the rate of production of new biomass by consumers, i.e., the rate at which consumers convert organic material into new biomass of consumers.
41 CONCLUSIONEnergy flow follows the second law of thermodynamicsBiomass decreases with increasing trophic levelEcological efficiency – typically 10%Food Web Activity
42 KEY CONCEPT Matter cycles in and out of an ecosystem.
43 Water cycles through the environment. Explain how. The hydrologic, or water, cycle is the circular pathway of water on Earth.Organisms all have bodies made mostly of water.precipitationcondensationtranspirationevaporationwater storagein oceansurfacerunofflakegroundwaterseepage
44 Elements essential for life also cycle through ecosystems. Name one. A biogeochemical cycle is the movement of a particular chemical through the biological and geological parts of an ecosystem.
45 Carbon is the building block of life. Why do we call it that? The carbon cycle moves carbon from the atmosphere, through the food web, and returns to the atmosphere.Carbon is emitted by the burning of fossil fuels.Some carbon is stored for long periods of time in areas called carbon sinks.fossil fuelsphotosynthesiscarbon dioxidedissolved in waterdecompositionof organismsrespirationcarbondioxidein aircombustion
46 Oxygen cycles indirectly through an ecosystem by the cycling of other nutrients. respirationcarbondioxidephotosynthesis
47 The phosphorus cycle takes place at and below ground level. Phosphate is released by the weathering of rocks.Phosphorus moves through the food web and returns to the soil during decomposition.Phosphorus leaches into groundwater from the soil and is locked in sediments.Both mining and agriculture add phosphorus into the environment.geologic upliftingrainweathering ofphosphate from rocksrunoffsedimentationforms new rocksleachingphosphate in solutionanimalsplantsdecomposersphosphatein soil
48 The nitrogen cycle mostly takes place underground. Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation.Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil.nitrogen inatmosphereanimalsdenitrifyingbacterianitrifyingammoniumammonificationdecomposersplantnitrogen-fixingbacteria in soilbacteria in rootsnitratesnitrites
49 Nitrogen moves through the food web and returns to the soil during decomposition. nitrogen inatmosphereanimalsdenitrifyingbacterianitrifyingammoniumammonificationdecomposersplantnitrogen-fixingbacteria in soilbacteria in rootsnitratesnitrites
50 How do the activities of a keystone species affect the biodiversity of an ecosystem? A. They increase biodiversity.B. They decrease biodiversity.C. They have no effect on biodiversity.D. Biodiversity remains the same but the species change.
51 How do the activities of a keystone species affect the biodiversity of an ecosystem? A. They increase biodiversity.B. They decrease biodiversity.C. They have no effect on biodiversity.D. Biodiversity remains the same but the species change.Correct Answer = AWhich is a characteristic of an ecosystem in approximate equilibrium?A. The kinds of organisms do not change.B. Biotic factors do not change.C. Abiotic factors do not change.D. The total number of organisms do not change.
52 How do the activities of a keystone species affect the biodiversity of an ecosystem? A. They increase biodiversity.B. They decrease biodiversity.C. They have no effect on biodiversity.D. Biodiversity remains the same but the species change.Correct Answer = AWhich is a characteristic of an ecosystem in approximate equilibrium?A. The kinds of organisms do not change.B. Biotic factors do not change.C. Abiotic factors do not change.D. The total number of organisms do not change.Correct Answer = D
53 ReviewProducers are organisms that can make their own energy from abiotic sourcesConsumers are organisms that must consume other organisms for energy.A food chain links organisms by their feeding relationships connecting a producer to a single line of consumers.A food web shows complicated feeding relationshipsWater, nitrogen, oxygen, phosphorous, and carbon all cycle through ecosystems.