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| An autotroph at the first trophic level of an ecosystem. |
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| Any animal that feeds on decomposing particles of organic matter. |
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| One of the prokaryotic or fugal heterotrophs that obtains carbon and energy by breaking down wastes or remains of organisms. The collective action of decomposers helps cycle nutrients to producers in ecosystems. |
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Array of organisms, together with their environment, interacting by a flow of energy and cycling of materials.
In nearly all ecosystems, both types of food webs interconnect (detrital & grazing food webs.) |
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| All organisms the same of transfer steps away from the energy input into an ecosystem. |
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| Linear sequence of steps by which energy stored in autotroph tissues enters higher trophic levels. |
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| Cross-connecting food chains consisting of producers, consumers, and decomposers, detritivores, or both. |
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Cross-connecting food chains in which energy flows from plants to an array of herbivores, then carnivores.
Energy captured by producers flows directly to consumers. |
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Cross-connecting food chains in which energy flows mainly from plants through arrays of detritivores and decomposers.
Energy captured by producers flows directly to detritivores and decomposers. |
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Ever increasing concentration of a slowly degradable or non-degradable substance in body tissues as it is passed along food chains.
Some chemical substance is pased from organisms at one trophic level to those above and becomes increasingly concentrated in body tissues. : DDT. |
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The rate at which an ecosystem's primary producers secure and store energy in tissues in a given interval.
Varies with climate, season, nutrient availability, and other factors. |
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| All the energy the primary producers have accumulated during growth, reproduction in a specified interval (net primary production), minus energy that producers, and decomposers, have used. |
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| Of an ecosystem, the combined weight of all organisms at a trophic level. |
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Diagram that depicts the energy stored in the tissues of organisms at each trophic level in an ecosystem. Lowest tier of the pyramid, consisting of primary producers, is always the largest.
Ecologists construct energy pyramids and biomass pyramids to show how energy and organic compounds are distributed in an ecosystem.
Energy pyramid is largest at their base. The lowest trophic level has the greatest proportion of the energy in an ecosystem. |
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Slow movement of an element from environmental reservoirs, through food webs, then back.
Water or nutrient moves through the environment, then through organisms, then back to an environmental reservoir. |
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| Any element having a direct or indirect role in metabolism that no other element can fulfill. |
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Biogeochemical cycle driven by solar energy; water moves through atmosphere, on or through land, to the ocean, and back to the atmosphere.
Water moves from the ocean into the atmosphere, to land, and back to the ocean-- the main reservoir. Human actions are disrupting the cycle in ways that result in shortages and pollution of water. |
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A region of any specified size in which all precipitation drains into one stream or river.
Plants absorb water from soil and groundwater stores. |
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Water in soil and aquifers.
Water moves from the ocean to the atmosphere, and back. |
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| Removal of salt from water. |
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Atmospheric cycle. Carbon moves from its environmental reservoirs (sediments, rocks, the ocean) through the atmosphere (mostly as CO2), food webs, and back to the reservoirs.
Moves carbon from its main reservoirs in rocks and seawater, through its gaseous from (carbon dioxide) in the atmosphere, and then through ecosystems. Deforestation and the burning of wood and fossil fuels are adding more carbon dioxide to the atmosphere than the oceans can absorb. |
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Trapping of heat near Earth's surface by the action of atmospheric gases. The gases absorb infrared wavelengths (heat) from the sun-warmed surface, and then radiate some wavelengths downward.
a) wavelengths in rays from the sun penetrate the lower atmosphere, and they warm the Earths surface.
b) The surface radiates heat (infrared wavelengths) to the atmosphere. Some heat escapes into space. But greenhouse gases and water vapor absorb some infrared energy and radiate a portion of it back toward Earth.
C)Increased concentrations of greenhouse gases trap more heat near Earth's surface. Sea surface temperatures rise, so more water evaporates into the atmosphere. Earth's surface temperature rises. |
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| Long-term increase in temperature of Earth's lower atmosphere. |
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| An atmospheric cycle, Nitrogen moves from its largest reservoir (atmosphere), then through the ocean, ocean sediments, soils, ad food webs, then back to the atmosphere. |
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One stage of the nitrogen cycle process. Bacteria convert gaseous nitrogen to ammonia, which dissolves in their cytoplasm to form ammonium for use in biosynthesis.
Some boil bacteria degrade N2 and assimilate the two nitrogen atoms into ammonia. Other reactions convert ammonia to ammonium and nitrate, which plats are able to take up. Some nitrogen is lost to the atmosphere by the action of denitrifying bacteria. |
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| Part of the nitrogen cycle; soil fungi and bacteria decompose nitrogen-containing compounds, the result being ammonia and ammonium ions that plant roots can absorb. |
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| One stage of the nitrogen cycle. Soil bacteria break down ammonia or ammonium to nitrite, then other bacteria break down nitrite to nitrate, which plants can absorb. |
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| Conversion of nitrate or nitrite to gaseous nitrogen (N2) or nitrogen oxide (NO2) by metabolic activity of certain bacteria in soil. |
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| pH- dependent process; ions dissociate from soil particles, then other ions dissolved in soil water replace them. |
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A sedimentary cycle. Phosphorus (mainly phosphate) moves from land, through food webs, to ocean sediments, then back to land.
Main sedimentary cycle. Earth's crust is the largest reservoir. PHosphorus is often the limiting factor on the population growth of producers. Excess inputs of phosphorus to aquatic ecosystems contribute to eutrophication. |
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| Nutrient enrichment of a body of water that promotes population growth of phytoplankton and opacity. |
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If organism B eats organisms A, energy is transferred from A to B. All organisms at a given trophic level are the same number of transfer steps away from the energy input into an ecosystem.
At each trophic level, organisms interact with the same sets of predators, prey, or both. Omnivores feed at several levels, so we would partition them among different levels or assign them to a level of their own. |
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| A number of food chains cross-connect with one another- as food webs. |
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First trophic level: Autotroph (Primary producer)
Second trophic level: Herbivore (Primary consumer)
Third trophic level: Carnivore (Second-level consumer)
Fourth trophic level: Carnivore (third-level consumer)
Fifth trophic level: Top carnivore (fourth-level consumer) |
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| Complex array of carnivores, omnivores, parasites, detritivores, decomposers, and other consumers. Many feed at more than one trophic level all the time, seasonally, or whenever an opportunity presents itself. |
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| Grazing food web flow through food webs |
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| Energy from sunlight -> Producers (photosynthesizers)->energy lost at each conversion step from one trophic level to the next -> herbivores (->energy in organic wastes remains -> decomposers) -> energy losses as metabolic heat and as net export from ecosystem -> carnivores ->energy losses as metabolic heat and as net export from ecosystem -> decomposers -> energy output. (Page 847) |
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| Detrital food web flow through food webs |
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Energy from sunlight -> producers (photosynthesizers) -> energy lost at each conversion step from one trophic level to the next
-> energy in organic wastes -> decomposers (energy losses as metabolic heat and as net export from ecosystem) & detritivores (energy losses as metabolic heat and as net export from ecosystem) -> energy output .
(Page 847) |
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| Kill weeds by disrupting metabolism and growth. |
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| Kill weeds by disrupting metabolism and growth. |
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| Clog the airways of a target insect, disrupt its nerves and muscles, or prevent its reproduction. |
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| Work against harmful fungi, including a mold that makes aflatoxin, one of the deadliest poisons. |
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Fairly stable hydrocarbon that is nearly insoluble in water. Winds can disperse DDT in vapor form, and water can disperse fine particles of it.
Due to molecular properties, DDT is highly soluble in fats, and so it can accumulate in the tissues of organisms.
DDT and it's modified forms disrupt metabolic activities are are toxic to many aquatic and terrestrial animals.
Several decades ago, DDT started to infiltrate food webs and exert its effects on diverse organisms in ways that no one had predicted. Where people sprayed DDT to control Dutch elm disease, songbirds died. In forests where DDT was sprayed to kill budworm larvae, fish in the forest streams died. In fields sprayed to control one kind of pest, new pests moved in.
DDT was indiscriminately killing natural predators that keep pest populations in check.
DDT can show biological magnification. |
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| How much energy gets stored depends on: |
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1) how many producers there are
2) the balance between photosynthesis (energy trapped) and aerobic respiration (energy used). |
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| All energy initially trapped by the producers. |
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| Fraction of trapped energy that producers funnel into growth and reproduction. |
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| Ecosystem phase of the nitrogen cycle |
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| Starts with nitrogen fixation. Bacteria convert gaseous nitrogen in the air to ammonia and then to ammonium, which is a form that plants easily take up. |
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| Ammonification phase of nitrogen cycle |
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| Bacteria and fungi make additional ammonium available to plants when they break down nitrogen-rich organic wastes and remains. |
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| Nitrification in nitrogen cycle |
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Bacteria convert nitrites in soil to nitrate, which also is a form that plants easily take up.
After that, the ecosystem loses nitrogen when denitrifying bacteria convert nitrite and nitrate back to gaseous nitrogen, and when nitrogen is leached from soil. |
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| Initial energy source for almost all ecosystems. Primary producers capture energy from the sun. They also assimilate nutrients that they, and all consumers, require. |
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| Organisms in an ecosystem are classified by trophic levels. Those at the same level are the same number of steps away from the energy input into the ecosystem. |
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| Trap heat in the lower atmosphere, which helps make Earth's surface warm enough to support life. Natural processes and human activities are adding more greenhouse gaes, including carbon dioxide, CFCs, methane, and nitrous oxide, to the atmosphere. The rise correlates with a rise in global temperatures and other climate changes. |
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