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Biosphere Unit NotesEcologyThe study of interactions that occur between organisms and their environment.Abiotic vs. Biotic FactorsAbiotic factors-all nonliving parts of an environment. Ex: temperature, light, soil, precipitationBiotic factors-all living parts of an environment. Ex: plants, animals, bacteriaAll of the biosphere adapts to survive in accordance with the abiotic and biotic factors of its environment.Levels of OrganizationListed in the chart with the top being the largest system, bottom the smallest.Population-group of same organisms that interbreed and compete for same munity-two or more populations that interact with one anotherEcosystem-the interactions amongst all biotic factors within an environment and the abiotic factors that contribute to an organism’s behavior.Koeppen Climate ClassificationClimate classification system developed to organize worlds based on air temperature and rate of precipitation.Five major categories: Tropical, Dry, Temperate, Continental, PolarBiomesBiomes are made of similar ecosystems and are controlled by climate. The climate of a region will determine what plants will grow there, and what animals will inhabit it. All three components, climate, plants and animals are interwoven to create the fabric of a biome.Types of Terrestial BiomesTropical rainforest-as many as 50% of all the world’s animal species may be found here; animal adaptations: camoflouge, colored markings indicates its poisonousGrassland-because of the dry climate, trees are found only near water sources such as streams; soil feature: very dark and fertile, allows many grasses to growTropical savanna-grasslands with a few scattered trees; plant adaptation: some trees pump chemicals in their leaves when threatened by biotic factorsDesert-animal adaptation: stores water in fatty tissues; plant adaptations: can become severely dehydrated and still surviveTemperate deciduous forest-moderate climate, experience seasonal changes; animal adaptations-migration and hibernation.Temperate boreal forest (taiga)-cold climate with summer rains; plant adaptation-dark colors absorb Sun’s energy more effecientlyTundra-a treeless and marshy plain; characterized by permafrost – permanently frozen soil starting as high as a few centimeters below the surface – which severely limits plant growth; animal adaptation-thick fur.Feeding RelationshipsAll organisms must “eat” in order to have energy to reproduce, grow, find food, and defend themselves.Ultimate source of energy for all life: sunAutotrophs /Producer- uses light to make their own food EX: plants, green algae Consumers/Heterotrophs depend upon autotrophs for nutrients and energy EX: deer, mice, lions, birds Types of HeterotrophsHerbivore-eats only autotrophs. Ex: deerCarnivore-eats only other heterotroph Ex: lionOmnivore-eats both autotrophs and heterotrophs. Ex: Bears Scavengers-eat heterotrophs that have died Ex: vulturesDecomposers-break down dead animals into simpler molecules that can be absorbed. Ex: Worms Trophic Levels and Food ChainsTrophic level: A feeding level in an ecosystemFood chain: lineup of organisms that shows who eats whoShows how matter and energy move through an ecosystem1st trophic level: producers (make their own food)2nd trophic level: primary consumer(eats plants)3rd trophic level: secondary consumer (eats meat) 4th trophic level: tertiary consumer (eats meat) EatenbyEatenbyEatenbyEatenbyLast trophic level: decomposer (eats dead animals) BacteriaEnergy Pyramids?Every time an organism eats, it obtains energy from its food?Energy pyramid - picture showing how much energy is transferred to the different trophic levels in a food chainThe higher the trophic level, the lower the amount of energy present. When the producer is eaten by the consumer, it is an exchange of energy. The consumer only receives 10% of the energy present in the producers. Therefore, to get enough energy to survive, the consumer must eat more producers, meaning that, to sustain the consumers, there must be many more producers.Also, there is much more energy to available to producers, which facilitates faster growth and larger numbers of producers1stProducersTrophic LevelEnergy Available2nd Primary consumers3rd Secondary consumers4th Tertiary consumers10 kcal/m2/year10,000 kcal/m2/year1000 kcal/m2/year100 kcal/m2/yearLimiting Factors of Energy Transfer in PyramidA limiting factor or limiting resource is a factor that controls a process, such as organism growth or species population size or distributionExamples of limiting factors include: availability of food, predation pressure, or availability of shelterBiodiversityIt is the genetic variation within populations and variation of populations within ecosystems; the variety of species in one area. The greater the biodiversity within an area, the greater the resources available to support the ecosystem.Why is Biodiversity Important?All living things are interdependent-any given species depends on the services of another species to survive. Limits chances of a species extinction-genetic variation in a population prevents one pest or disease from completely wiping out the population. Variety of organisms help to maintain an ecosystem-organisms collectively can contribute to soil formation, pollution breakdown, nutrient storage, or contribute to climate stability.Greater biodiversity provides larger pool of resources-more organisms we can use for food, medicinal purposes, wood products, animals for breeding stocks, etc. Threats to BiodiversityHuman Population GrowthCurrent birth rate is higher than death rate, so Earth’s population is steadfastly increasing. Demand for resources is increasing. However, the amount of resources is not increasing.At some point, Earth’s population may go beyond its carrying capacity and there will not be enough resources to supply the needs of the population. Invasive SpeciesA nonnative species whose introduction causes economic, environmental, human health issues by disrupting ecosystem. Take resources from native species, causing native species population to decrease.Ex: kudzu, zebra musselsHabitat AlterationAny change that occurs to an existing habitat.Clear cutting-removing all plants, destroying habitats Selective cutting-removing only parts of a region, causing habitat fragmentation, separating species from one another, increasing or decreasing populations as a resultOverharvestingConsuming too much of a population severely decrease their numbers, therefore causing a disruption in the food chain.Pollution-Habitat DegradationHabitat degradation is the damage done to a habitat by pollution – air, land, or water.Examples of Habitat DegradationAcid rain is any precipitation that has a low pH value. It is caused by water in the atmosphere becoming acidified due to coal burning factories, car exhaust, and other sources. Acid rain Results in damage to plant tissue and can affect aquatic species ability to survive Eutrophication occurs when fertilizer and animal waste runoff are carried into hydrosphere. These nutrients allow algae blooms to occur. As the algae dies and decays, it removes oxygen from the water, killing the fish and creating dead zones. Inappropriate trash disposal-dumping of waste into environment can cause disruption of ecosystems and be lethal to some organisms.Consequences of Loss of BiodiversityExtinction – disappearance of a species; current rate of extinction has acceleratedEcosystem collapse – if keystone species is removed, the entire ecosystem could collapse, causing population sizes to be unstablePossible loss of medicinal cures for diseases – unknown how many or what types of plants could contribute to medicineOther consequences may still be unknown to us – many ecosystems are so complex that ecologists cannot begin to predict ramifications of biodiversity loss How Do We Protect Biodiversity?Conservation biology – the study and implementation of methods to protect biodiversityLegislation designed to preserve habitats Reintroduction and Captive Breeding ProgramsReducing “ecological footprint” ................
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