Presentation on theme: "Chapter 2 – Introduction to Ecology"— Presentation transcript:
1 Chapter 2 – Introduction to Ecology Section 1: Organisms and Their Relationships
2 EcologyEcologythe study of the interactions between organisms and the biotic and abiotic components of their environment
3 The BiosphereThe biosphere is the portion of Earth that supports life.“bio” means life“sphere” refers to the shape of our planet that resembles a ball“The ball of life”Includes our atmosphere, landmasses, bodies of freshwater and saltwater, and locations below the Earth’s surface that supports life.
4 The Biosphere Cont. Biotic Factors Abiotic Factors All of the LIVING things in an organism’s environment.Abiotic FactorsAll of the NONLIVING things in an organism’s environmentIncludes temperature, air currents, sunlight, rainfall, soil type and available nutrients
5 A Key Theme in Ecology No single organism is isolated!! The interconnectedness or interdependence of all organisms is central to the study of ecologyThe survival of organisms depends on their interactions with their surrounding environmentEx: Humans cannot live without the plants that produce food and oxygen
7 The BiosphereBiosphere: the broadest and most inclusive level of organizationThe Earth and its atmosphere make up our biosphereExtends from 8 to 10 km (5-6 miles) above the Earth’s surface to the deepest parts of the ocean
8 EcosystemsThe biosphere is comprised of smaller units called ecosystemsIncludes all of the organisms and the abiotic environment found in a specific placeEx: Pond EcosystemAbiotic components: water temperature, amount of dissolved oxygen and carbon dioxide, the pH levelBiotic components: insects, fish, algae, aquatic plants, turtlesSome ecosystems can be considered the habitat of an organism.
10 The Niche Niche the role an organism plays in its environment Includes:Range of conditions the organism can tolerateMethods by which it obtains resourcesInteractions with its environment such as reproduction
12 Community Interactions all of the interacting organisms living in an areaEx: All of the fish, turtles, insects, plants and algae make up the community of a pondCompetition occurs when more than one organism uses a resource at the same time.Ex: Lions and hyenas compete for the same food sources.Predation is the act of one organism consuming another for food.
14 Symbiotic Relationships Most species survive because of relationships called symbiosisMutualism:Both organisms benefitEx: The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos
15 Symbiotic Relationships Commensalism:One benefits; the other is not affectedEx: Sea anemone and the clown fish.Parasitism:One benefits at the expense of the otherEx: Deer tick and mammal
17 Chapter 2 – Principles of Ecology Section 2: Flow of Energy in an Ecosystem
18 Energy in an Ecosystem Autotrophs: primary producers make their own foodUse energy from sunlight or inorganic substancesFoundation of all ecosystemsthey make energy available for all of the other organismsEx: Plants
19 Energy in an Ecosystem Heterotrophs: get energy by consuming other organismsCalled “consumers”Herbivoreseat only plantsCarnivoreseat others
20 Energy in Ecosystems Heterotrophs Cont: Omnivores Detrivores eat both plants and animalsDetrivoreseat dead/decaying materialDecomposers are similar to detrivoresBreak down dead organisms by releasing digestive enzymes (fungi)Important because they make nutrients available for all other organisms
21 Models of Energy FlowEcologists use food chains and food webs to show energy flow in ecosystemsTrophic levelEach step in a food chain or food webAutotrophs are the first trophic level in ALL food chains and food webs!
22 Important Terms for Food Chains and Food Webs Primary producers: make their own foodPrimary consumers: eat the primary producersSecondary consumers: eat the primary consumersThird-level consumers: eat the secondary consumers
23 Food ChainsFood chains: a simple model that shows how energy flows through an ecosystemArrows show one-way energy flowEach organism uses some of the energy from the organism it eatsThe remaining energy is lost to the surrounding environment
24 Food WebsFood webs: models that represent the interconnected food chains in which energy flows through a group of organisms
25 Ecological PyramidsDiagrams that show the relative amounts of energy, biomass or numbers of organisms at each trophic levelBiomass is the total mass of living matter at each trophic levelApproximately 90% of all energy at a tropic level is NOT transferred to the level above it
27 Cycles of the Biosphere Energy is not recycled in a ecosystemMatter (biomass) is recycled in a ecosystemNutrient: a chemical substance that an organism needs from its environment.Nutrient cycling involves both the biotic and abiotic portions of an ecosystem.These are called the biogeochemical cycles.
28 The Water Cycle: more of a physical process than a chemical one.
29 The Water Cycle Key Terms: Evaporation: water returning to the atmosphere from oceans, lakes, and riversTranspiration: water returning to the atmosphere from the surface of plantsPrecipitation: water returning to the earth from the atmospherePercolation: water running through the soilRunoff: water running on the surface of the earth.
30 The Carbon CycleTwo natural processes help to cycle carbon through the ecosystem.Photosynthesis:autotrophstake in CO2 and produce organic compoundsMake them available then for consumers.Cellular Respiration;both autotrophs and heterotrophsconvert energy rich organic compounds into ATPpowers cellular functions.
31 The Carbon Cycle Deposition Carbonate in sediments: dead materials: converted to peat, coal, oil or gas deposits (carbon stored as fossil fuel)carbon is released when fossil fuels are burnedCarbonate in sediments:shells, coral, algae fall to bottom of ocean creating limestone rock.Carbon is released in the form of bicarbonates
33 There are none! Brain Break Try to count the number of black dots on the image below...There are none!
34 The Nitrogen CycleNitrogen enters ecosystems through two natural pathways.Nitrogen fixation, where certain bacteria convert N2 to minerals that can eventually be used by plants to produce nitrogenous organic compounds.
35 The Nitrogen CycleChemical nitrogen fixation - lighting bolts change nitrogen gas to nitrates or nitrogen is added to the soil by chemical fertilization.Some bacteria break down detritus and animal waste producing ammonium through AmmonificationCertain bacteria convert ammonium into nitrate, a process called Nitrification.Nitrate can be used by plants.
36 The Nitrogen CycleSome bacteria take oxygen from the nitrate and release N2 back into the atmosphere called Denitrification.
37 WHAT IS PRODUCED (Products) PROCESSBy What OrganismCompounds UsedWHAT IS PRODUCED (Products)NITROGEN FIXATIONNitrogen fixing bacteria in soil and in legume roots.Nitrogen Gas (N2)Usable nitrogen:Nitrates (NO3-) made in roots of legumes and Ammonium (NH4+) and in the soil.AMMONIFICATIONDecomposers (Bacteria and Fungus)Detritus and wasteAmmoniaNITRIFICATIONNitrifying BacteriaAmmoniumNitrites (NO2-) & NO3-ASSIMILATIONChemical reactions in the organism.NitratesAny nitrogen based compound needed by plants and animals. Nitrogen is used to make amino acids.DENITRIFICATIONDenitrifying BacteriaExcess nitratesNitrogen Gas
40 Phosphorus cycle Needed for growth and development Short term- cycled from soil to producers and producers to consumersLong term- Phosphorus comes from weathering and erosion of rocks
41 Rates of nutrient cycling Decomposition rates largely determine the rates of nutrient cyclingThe rate at which nutrients cycle in an ecosystem depends on the rate of decomposition.Decomposition can take up to 50 years in the tundra, while in the tropical forest, it occurs much faster.Quantities of nutrients in the soil of different ecosystems also varies, depending on the rate of absorption by the plants.
42 Nutrient cycling is strongly regulated by vegetation In a terrestrial ecosystem most of the mineral nutrients cycle within the ecosystem.In addition to the natural ways, nitrogen- containing fertilizer contributes to the total amount of nitrogen materials in ecosystems.