Terrestrial ecosystems forests Forests dominated by trees Ex Tropical rain forest Coniferous forests taiga Temperate deciduous Grasslands dominated by grass Ex Tropical grasslands Temperate grasslands prairie Deserts characterized by lack of available moisture Ex Tundra Deserts Niche the role an organism plays in an ecosystem such as how it gets its food what it eats and how it interacts with other organisms Aquatic ecosystems Marine Ex Seashores Oceans Coral reefs Estuaries Freshwater Ex Lakes Ponds Rivers Streams Components of an ecosystem Abiotic components nonliving environment Biotic components living components o Autotrophs producers o Heterotrophs consumers Herbivores feed on plants and algae Carnivores feed on other animals Omnivores eat both plants and animals Detritus feeders feed on decomposing organic matter Energy flow and chemical cycling Energy flow o It begins and continues when producers absorb solar energy o Energy flow occurs as nutrients pass from one o This energy is converted to heat that dissipates into the population to another environment o Only a portion of energy is passed to organisms as they consume one another Chemical cycling o Inorganic nutrients are returned to producers from the atmosphere or soil o Chemicals recycle within and between ecosystems Fate of food energy taken in by an herbivore Energy Flow Food web describes who eats whom in an ecosystem Trophic levels composed of all organisms that feed at a particular link in the food chain o Producers primary consumers and secondary o Ecological Pyramid reflects the loss of energy from one consumers trophic level to another Only about 10 of the energy of one trophic level is available to the next trophic level Biogeochemical cycles are pathways by which chemicals circulate through an ecosystem Chemical cycling o Water cycle o Carbon cycle o Nitrogen cycle o Phosphorus cycle limited in availability Reservoir fossil fuels minerals in rocks and sediments in oceans contain inorganic nutrients that are Exchange pools atmosphere soil and water are ready sources of inorganic nutrients Water cycle the ground surface waters or aquifers Human activities that interfere Water evaporates from bodies of water land and plants and returns when water falls on land to enter o Withdrawing water from aquifers o Clearing vegetation from the land and building structures that prevent percolation and increase runoff o Adding pollutants to water such as sewage and chemicals Carbon cycle CO2 is exchanged between the atmosphere and living organisms Plants incorporate atmospheric CO2 into nutrients through photosynthesis providing food for themselves and other organisms CO2 is returned to the atmosphere through respiration Human activities that interfere o Burning of fossil fuels and the destruction of forests are adding CO2 to the atmosphere faster o CO2 and other gases N2O and CH4 are being emitted due to human activities o These gases are called greenhouse gases because they trap heat this contributes to global than it is being removed warming Nitrogen cycle Whatever is not absorbed by plants bacteria removes it and releases pure oxygen into atmosphere 78 of the atmosphere is nitrogen gas N2 but plants cannot use this form Nitrogen fixing bacteria convert nitrogen gas to ammonium NH4 which can be used by plants Nitrifying bacteria convert ammonium to nitrate NO3 Bacteria convert nitrate back to nitrogen gas through a process called denitrification Human activities that interfere o We add nitrogen fertilizers that run off into lakes and streams causing major fish kills eutrophication o Burning of fossil fuels o Puts nitrogen oxides and sulfur dioxide into the atmosphere where they combine with water vapor to form acids that return to earth as acid deposition o Result in nitrogen oxides and hydrocarbons that react with one another to produce smog Biomagnification of Mercury one of the human interferences in nature Emissions of mercury into the environment can lead to serious health effects for humans fish and There is widespread mercury contamination in streams wetlands reservoirs and lakes throughout Bioaccumulation occurs when an organism accumulates a contaminant such as mercury faster than it Mercury enters ecosystems at the base of the food chain and increases in concentration as it moves up wildlife most of the U S can eliminate it higher trophic levels Phosphorus cycle Phosphate ions become available to living organisms by the slow weathering of rocks Phosphate is a limiting nutrient in ecosystems Human activities that interfere o Runoff of phosphate due to fertilizer and discharge from sewage treatment results in eutrophication Extra Details There is always loss of energy Global Warming increase in average temperature DNA RNA aminoacids and the atmosphere has nitrogen There is mostly nitrogen in the atmosphere Phospholipids nucleic acids DNA RNA some proteins have phosphorus There is no genetic content nor energy supply without phosphate Ecosystems affect energy flow
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