Populations and Ecosystems
Classroom Notes on the ecology unit
Published on: Mar 4, 2016
Transcripts - Populations and Ecosystems
Populations and Ecosystems The Biosphere Trophic Levels Interaction and Adaptation Changing Ecosystems Invasive SpeciesThe Structure of the Biosphere The Biosphere Biomes Ecosystems Communities Populations
The Biosphere: The part of the Earth where living organisms and organic matter existsThe biosphere includes all areas that contain life, which include the hydrosphere (waterenvironments) the atmosphere (air environments)and the geosphere (ground and soilenvironments). Anywhere that humans habitat is called the anthrosphere. Biome: Regions of the Earth that share similar climates, vegetation and animal life. The life found in these regions are specially suited for survival in that particular environment. There are six main biomes Freshwater Marine Desert Forest Grassland Tundra Of course, these can be divided up into more specific biomes such as tropical rain forest, temperate rain forest, coniferous forest, and so on...
Ecosystems: Living organisms interacting with each other and the non-living factors in an environment Abiotic vs. Biotic factorsCommunitiesAll the interacting living organisms within an ecosystem(Animal, plant, fungi...)
Population:The total number of organisms of one species that live in a particularecosystem at one time Abiotic Factors: All the non-living parts of an environment Biotic factors: All the living factors of an environment
Organic Matter: Matter that has come from a once-living organism; capable of decay, or is the product of decay Characterized by molecules that contain both carbon and hydrogen (hydro-carbons) Inorganic Matter: Matter from a non-living source such as rocks, sand or plastic; Molecules do not contain both carbon and hydrogenTrophic LevelsEnergy and the Trophic PyramidEnergy is the ability to do work. All living things need energy tosurvive. This shows how energy is distributed in an ecosysem. Energystarts at the bottom of the pyramid with the producers and works itsway up to the upper levels. Tertiary Consumers Secondary Consumers Primary Consumers Primary Producers Lets look at some examples...
Its all a matter of mathematics. Anorganism can only survive if there isenough energy available in thetrophic level below it.
Interaction and AdaptationInteractions: How organisms respond or behave around otherorganismsCompetition: The struggle to obtain various limited resources within the environment. Resources can include: · Water · Food · Living space (habitat) · Light energy · ReproductionCan take place between individuals of the same species or differentspecies
How might plants competewith each other?Symbiosis: Individuals of different speciesthat have a close relationship with eachother
Mutualism: The interaction between two different organisms of different species where both benefitCommensalism: The interaction between two different organisms of different species where one benefits and the other is unaffected
Parasitism: The interaction between two different organisms of different species where one benefits and the other is harmedAdaptation:Helps organisms survive and thrive in their particular habitatAdaptations come from variations within the species.If an organism is born with a sightly different trait (a longer beak, a slightlydarker color, etc.) that gives it a survival advantage, the organism is more likelyto survive and pass that trait onto its offspringThe trait can provide an advantage to surviving... - In a particular climate - In a particular habitat - A predator - By finding/obtaining a food sourceA change in any of these can cause one trait tobecome less or more advantageous.
There are two types of adaptations:Behavioral Adaptations: A way an organism behaves or interacts thatgives an organism a survival advantage in a specific ecosystem or habitatMoving in large groups is a behavioral adaptation; it helps protect themembers of the group from predators.Structural Adaptations: A physical characteristics that gives an organisma survival advantage in a specific ecosystem or habitatAn arctic fox has a thick fur coat that helps it survive in extremely coldweather. It is also white, so it blends in with the snow. A red fox is not ableto hide from its prey in that environment, so it is not as successful. Natural Selection: The process in which individuals members of species are "selected" by the environment for survival because variations that give the individual an advantage. These genetic variations make it more likely that an organism will survive and therefore pass on the successful trait to its offspring. The result is a slow change in the species over many years.
Changing EcosystemsPopulations change: All populations change over time: Grow or Decline --Birth rates --Available food --Predators and prey interactionsLimiting Factors: Factors or conditions in the environment that limit a populations sizeExamples: Predator/prey relationships? Reproductive? Available Resources? Seasons?Carrying CapacityThe maximum number of individuals that anecosystem can supportEcosystems Change Over TimeSuccession:Gradual change of an ecosystem when one communityreplaces another. Primary Secondary