The Trophic structure of an ecosystem describes the feeding relationshipsEnergy enters an ecosystem as sunlightTrophic level 4 — tertiary consumersTrophic Level 3— Secondary consumersTrophic Level 2 — Primary consumersTrophic Level 1— primary producers (autotrophs – self feeders)Decomposers break down nonliving matterAt each energy conversion, heat is released.Elements cycle through the biosphereEnergy flows through ecosystemsChemical elements such as carbon and nitrogen cycle through the biosphere.Elements move from abiotic reservoirs such as air, soil and water, to biotic components of ecosystems in a biogeochemical cycle.Biogeochemical cycles occur both locally and globallyAbiotic reservoirsInclude the atmosphere, rocks, and oceanBiotic ReservoirsLiving thingsThe carbon cycle is an example of a biogeochemical cycleThe carbon cycle is affected by human activities, primarily the burning of fossil fuels, which releases trapped carbon into the atmosphere as CO2The nitrogen cycle is an example of a biogeochemical cycleNitrogen is only available to living things after soil bacteria convert N2 to compounds that plants can take up. Human effects on the nitrogen cycle are show in red.Is energy recycled?NOEnergy flow is one-wayEnergy input from sun  autotrophs  heterotrophsEnergy is transformed from one form to anotherLight energy  heat energyLight energy  chemical energy  heat energyHEAT ENERGY CANNOT BECOME ANY FORM OF ENERGY THAT ORGANISMS CAN USE TO LIVE!Too much nitrogen or phosphorusAbundance of nutrientsLeads toIncreased pant growthLeads toUnbalanced food webLeads toDead plants being decomposed, which removes oxygen from the water called HYPOXIAleads toDeath of many organismsAcid rain occurs because the following biogeochemical cycle is disrupted:Nitrogen and SulfurWhich state has the most acidic precipitationPennsylvaniaMost of the coal burning power plants are in the Midwest and southeast. So why is there more acidic rain on the eastern united states?Prevailing winds from the west.Energy transformation is wasteful.Net primary productivityDifferent ecosystems can be compared by the amount of energy their primary producers can store in their tissues.Limiting factors: abiotic factors that limit the primary productivity of an ecosystemAmount of waterAmount of sunlightAvailability of nutrientsAppropriate temperatures.Abiotic limiting factorsTerrestrial biomes are limited by:TemperaturewaterAquatic Biomes are limited by:EnergyNutrientsEcologists categorize the earth surface into a series of biomesVery importantBecause limited energy is available to organisms, the survival of an organism depends on the ability to get enough energyTherefore, organisms must compete with other organisms of their same species and with other species in order to surviveBiologists describe smaller environments as habitatsWhat does a habitat contain?Biotic factors?Abiotic factors?How is a habitat related to a community?What is a niche?A set of conditions within which an organism can maintain a viable population— abiotic and biotic factors too.More than just a place for living , a niche is a complete way of livingNiche FeaturesThe space an organism requiresThe types and amount of food an organism utilizedThe timing of an organisms reproductionAn organisms temperature and moisture requirements and other necessary living conditions.You cant always get what you wantFundamental nicheThe full range of environmental conditions under which a species can liveRealized nicheWhere and how a species is actually living.Competition for resources between different species – two outcomesCompetitive exclusion— two species cannot occupy the same nicheOrResource partitioningKeystone species — who is top dog?A species who absence would create significant change in a community.Often top predatorsNot all communities have keystone speciesBIO 101 1nd Edition Lecture 21 Outline of Last Lecture II. What is ecology?III. Density Dependent factorsIV. Poverty in IndiaV. VariationOutline of Current Lecture VI. BiosphereVII. Carbon cycle VIII. Nitrogen cycleCurrent Lecture The Trophic structure of an ecosystem describes the feeding relationships- Energy enters an ecosystem as sunlight- Trophic level 4 — tertiary consumers- Trophic Level 3— Secondary consumers- Trophic Level 2 — Primary consumers- Trophic Level 1— primary producers (autotrophs – self feeders)- Decomposers break down nonliving matter- At each energy conversion, heat is released. Elements cycle through the biosphere- Energy flows through ecosystems- Chemical elements such as carbon and nitrogen cycle through the biosphere.- Elements move from abiotic reservoirs such as air, soil and water, to biotic components of ecosystems in a biogeochemical cycle. These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Biogeochemical cycles occur both locally and globally- Abiotic reservoirso Include the atmosphere, rocks, and ocean- Biotic Reservoirs o Living things The carbon cycle is an example of a biogeochemical cycle- The carbon cycle is affected by human activities, primarily the burning of fossil fuels, which releases trapped carbon into the atmosphere as CO2 The nitrogen cycle is an example of a biogeochemical cycle- Nitrogen is only available to living things after soil bacteria convert N2 to compoundsthat plants can take up. Human effects on the nitrogen cycle are show in red.  Is energy recycled?- NO- Energy flow is one-wayo Energy input from sun  autotrophs  heterotrophs- Energy is transformed from one form to anothero Light energy  heat energyo Light energy  chemical energy  heat energy- HEAT ENERGY CANNOT BECOME ANY FORM OF ENERGY THAT ORGANISMS CAN USE TO LIVE! Too much nitrogen or phosphorus- Abundance of nutrientso Leads to- Increased pant growtho Leads to- Unbalanced food webo Leads to- Dead plants being decomposed, which removes oxygen from the water called HYPOXIA o leads to- Death of many organisms Acid rain occurs because the following biogeochemical cycle is disrupted:- Nitrogen and Sulfur Which state has the most acidic precipitation- Pennsylvania Most of the coal burning power plants are in the Midwest and southeast. So why is theremore acidic rain on the eastern united states?- Prevailing winds from the west.  Energy transformation is