GEOG 203 Exam 3 Study Guide Chapter 19 Ecosystem Essentials Ecosystem Components Abiotic Temperature precipitation latitude altitude Oxygen Carbon Nitrogen cycles Biotic Producers Consumers and Decomposers Food webs Trophic levels Assimilation efficiency Ecosystem Self sustaining associations of plants animals and their physical abiotic environment Ecology the study of the relationships between organisms and their environment Biogeography study of the spatial patterns and distribution of plants and animals Population Controlling Factors Increasing growth Abiotic favorable light adequate water temperature chemicals Biotic reproductive success adaptability to change ability to compete migrate defend adequate food Decreasing growth Abiotic unfavorable weather lack of water changes in chemical environment climate change Biotic reproductive failure lack of suitable habitat lack of food predators parasites disease Food Chains Trophic Levels o Producer Primary consumer Secondary consumer o Tertiary consumer Decomposer Food Webs Complexity leads to stability Diversity means you have a variety of foods you can consume Energy Nutrient and Food Pathways It all leads to energy and heat o What we don t absorb as energy is released as heat Biomass consumption and assimilation efficiency 10 Trophic level distribution in two ecosystems Grassland has a standard pyramid format because of the high amount of producers Temperate forest has a low level of producer and then thick middle sections with a thin top tertiary consumer Energy Budget of the Biosphere Net Primary Productivity Is the rate at which plants incorporate atmospheric carbon through photosynthesis High amounts of precipitation and insolation lead to the highest primary productivity The Gulf Coast Dead Zone 41 of the continental US drains through the Mississippi into the Gulf of Mexico creating this dead zone Temperature and Precipitation Carbon and Oxygen Cycles Nitrogen Cycle Ecosystems and Succession Ecosystem Stability and Diversity o Greater biodiversity in an ecosystem results in greater stability and greater productivity Ecological Succession o Occurs when newer communities usually more complex replace older communities of plants and animals usually simpler a change of species composition Terrestrial Succession o An area of bare rock or a disturbed site with no vestige of a former community can be a place for primary succession the beginning of an ecosystem o In terrestrial ecosystems succession begins with early species that form a pioneer community o Secondary succession is more common in nature which begins if some aspects of a previously functioning community are present Mount St Helens is an example of secondary succession Aquatic Succession Chapter 11 The Dynamic Planet The Pace of Change Geologic Time Scale o Earth is 4 6billion years old First Hominids 1 800 000 ybp First Agriculture 10 000 ybp o Time scales Relative event sequences superposition Absolute actual age o Learn Precambrian Eon 88 3 of Earth s History 542 000 000 years Phanerozoic 11 7 Cretaceous 65 6 million years o Had major extinctions ended with the Dinosaurs Extinction o Part of Mesozoic Era 4 of Phanerozoic Holocene Epoch 12 000 years 0 01 Era of humans Anthropocene o Proposed new name for the Holocene Earth s Structure and Internal Energy Earth congealed from a nebula 4 6 billions years o Gravity sorted by density o Concentric rings Core most dense Crust least dense Floating on top We know this due to seismic shock waves Earth s Core o Inner Core Most dense Solid Iron o Outer Core Molten iron Magnetic field Earth s Mantle Earth s Lithosphere and Crust o Core to Crust Earth s radius is over 6 000km We have only drilled 12km o Lithosphere crust uppermost mantle o 2 types of crust Oceanic Crust Denser Basaltic Fine grained Continental Crust Less dense Granitic Large grain crystalline o Asthenosphere o Plastic The Geologic Cycle Minerals vs Rocks o Mineral inorganic non living natural compound has a specific chemical formula and crystalline structure Example quartz SiO2 pyrite FeS2 iron sulfide o Rock assemblage of minerals or a mass of a single mineral or solid organic material o Example granite Rock Cycle o Igneous Processes Fire formed solidifies from cooling magma or lava Igneous Rocks Magma is molten rock beneath the surface intrusive Lava is molten rock at the surface extrusive Igneous rocks are products of the crystallization of magma and lava o Intrusive slower cooling larger crystals o Extrusive Faster cooling smaller crystals o Sedimentary Processes Sediments sediments worn from other rocks Sediments are loose particles of former rocks ranging from mineral grains to boulders Acted upon by cementation compaction and hardening of sediments lithification o Example sandstone shale limestone coal o Metamorphic Processes Change form changing the chemistry mineralogy or texture of other rocks Rocks that are transformed from extreme pressure and heat Physically and chemically different Harder more resistant to erosion o Change of form Granite Gneiss o Also Shale Slate o Limestone Marble o Sandstone Quartzite Plate Tectonics Changes in the configuration of the earth s crust due to internal force The processes involved include o Upwelling of magma o Sea floor spreading and subduction o Plate movements A Brief History Sea Floor Spreading and Production of New Crust o Ocean floor Subduction creates deep trenches spreading creates ridges Subduction of the Crust The Formation and Breakup of Pangaea Plate Boundaries o Earth s crust is composed of 14 plates Complex pattern of plate movement Divergent plates move apart and new oceanic crust forms Sea floor spreading New crust being created is a constructional process Most area associated with mid ocean ridges Convergent continental and oceanic crust collides Produces subduction zones mountains volcanoes Zones of compression and crustal loss Destructional Transform plates slide past one another Earthquake and Volcanic Activity Hot Spots o Upwelling material arriving at the surface from the mantle o Occur beneath both continental and oceanic crust o Some are fixed others move Chapter 12 Tectonics Earthquakes and Volcanism Orogenesis Mountain Building Caused by 3 types of convergent plate collisions o 1 Oceanic continental plate collision Ex Pacific coast of South America o 2 Oceanic oceanic plate collision Ex Chain of islands in the western Pacific o 3 Continental continental plate collision Ex Alps and Himalayas