Ecosystems and Restoration Ecology
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| 15532247708 | Ecosystem | All organisms in a given area and the abiotic factors with which they interact; involves energy flow and chemical cyling | 0 | |
| 15532247709 | Law of Conservation of Mass | Matter cannot be created or destroyed •Chemical elements are continually recycled within ecosystems •In a forest ecosystem, most nutrients enter as dust or solutes in rain and are carried away in water •Ecosystems are open systems, absorbing energy and mass and releasing heat and waste products | 1 | |
| 15532247710 | Primary Producers | Autotrophs, usually photosynthetic, who create sugars to use as food | 2 | |
| 15532247711 | Primary Consumers | Herbivores who eat producers | 3 | |
| 15532247712 | Secondary Consumers | Carnivores that eat herbivores | 4 | |
| 15532247713 | Tertiary Consumers | Carnivores that eat carnivores | 5 | |
| 15532247714 | Detritivore (Decomposer) | Heterotrophs that gain energy from detritus, nonliving organic matter •Detritivores are animals -Produce organic wastes further broken down by •Decomposers -Fungi and prokaryotes -Produce inorganic wastes •Decomposition connects all trophic levels | 6 | |
| 15532247715 | detritus | nonliving organic material, such as the remains of dead organisms, feces, fallen leaves, and wood | 7 | |
| 15532247716 | Primary Production | Amount of light energy converted to chemical energy by autotrophs during a given time period •In most ecosystems, primary production is the amount of light energy converted to chemical energy by autotrophs during a given time period •In a few ecosystems, chemoautotrophs are the primary producers •The extent of photosynthetic production sets the spending limit for an ecosystem's energy budget •1% of visible light that strikes photosynthetic organisms is converted to chemical energy •= 150 billion metric tons of organic material per year | 8 | |
| 15532247717 | Gross Primary Production | Total primary production in an ecosystem •GPP is measured as the conversion of chemical energy from photosynthesis per unit time | 9 | |
| 15532247718 | Net Primary Production | GPP minus the energy used by primary producers for cellular respiration •NPP is expressed as either -Energy per unit area per unit time (J/m2×yr), or -Biomass added per unit area per unit time (g/m2×yr) •NPP is the amount of new biomass added in a given time period •Only NPP is available to consumers •Standing crop is the total biomass of photosynthetic autotrophs at a given time •Satellite data indicates that ecosystems vary greatly in NPP and contribution to the total NPP on Earth | 10 | |
| 15532247719 | autotrophic respiration | Ra | 11 | |
| 15532247720 | Net Ecosystem Production | Measure of total biomass accumulated in a given time period. GPP - Rt | 12 | |
| 15532247721 | total respiration of all organisms in the system | Rt | 13 | |
| 15532247722 | Limiting Nutrient | Element that must be added for production to increases •More than light, nutrients limit primary production in most oceans and lakes •Nitrogen and phosphorous are the nutrients that most often limit marine production •Nutrient enrichment experiments confirmed that nitrogen was limiting phytoplankton growth off the shore of Long Island, New York •Often touted as a quick fix to reduce atmospheric CO2 |  | 14 |
| 15532247723 | Eutrophication | Process of increasing the nutrients in lakes and thus decreases oxygen and clarity | 15 | |
| 15532247724 | Light and nutrients | Limits of primary production in aquatic ecosystems | 16 | |
| 15532247725 | Temperature and moisture | Limits of primary production in terrestrial ecosystems | 17 | |
| 15532247726 | Secondary Production | Amount of chemical energy in a consumer's food that is converted to their own new biomass in a period of time |  | 18 |
| 15532247727 | Net Secondary Production | The gain by consumers in energy or biomass per unit time remaining after allowing for respiratory losses (R). | 19 | |
| 15532247728 | Production Efficiency | Percent of energy stored in assimilated food which is not used for respiration •When a caterpillar feeds on a leaf, only about one-sixth of the leaf's energy is used for secondary production •An organism's production efficiency is the fraction of energy stored in food that is not used for respiration - Production Efficienty = Net secondary production / Assimilation of primary production x 100% |  | 20 |
| 15532247729 | Trophic Efficiency | Percent of production transferred from one level to the next, only about 10% (range of 5% to 20%) •Trophic efficiency is multiplied over the length of a food chain •Approximately 0.1% of chemical energy fixed by photosynthesis reaches a tertiary consumer •A pyramid of net production represents the loss of energy with each transfer in a food chain |  | 21 |
| 15532247730 | Biogeochemical Cycles | Cycling of nutrients involving both biotic and abiotic factors | 22 | |
| 15532247731 | Carbon Cycle | Key processes in this cycle involve photosynthesis and cellular respiration. •Carbon-based organic molecules are essential to all organisms •Photosynthetic organisms convert CO2 to organic molecules that are used by heterotrophs •Carbon reservoirs include fossil fuels, soils and sediments, solutes in oceans, plant and animal biomass, the atmosphere, and sedimentary rocksCO2 is taken up and released through photosynthesis and respiration; additionally, volcanoes and the burning of fossil fuels contribute CO2 to the atmosphere |  | 23 |
| 15532247732 | Phosphorous Cycle | Key processes include weathering, leaching, and decomposition/ excretion |  | 24 |
| 15532247733 | Nitrogen Cycle | Key processes include dentrification, ammonification, nitrification, and fixation •Nitrogen is a component of amino acids, proteins, and nucleic acids •The main reservoir of nitrogen is the atmosphere (N2), though this nitrogen must be converted to NH4+ or NO3- for uptake by plants, via nitrogen fixation by bacteria •Organic nitrogen is decomposed to NH4+ by ammonification, and NH4+ is decomposed to NO3- by nitrification •Denitrification converts NO3- back to N2 |  | 25 |
| 15532247734 | Nitrogen fixation | Conversion of N2 into forms of nitrogen that can be used by organisms | 26 | |
| 15532247735 | Nitrification | Process by which bacteria oxidizes NH4 into nitrite and then nitrate | 27 | |
| 15532247736 | Denitrification | Bacteria releases nitrogen back into the air | 28 | |
| 15532247737 | Bioremediation | Using organisms like prokaryotes, fungi, or plants, to detoxify polluted ecosystems | 29 | |
| 15532247738 | Biological Augmentation | Adding organisms to speed up succession of ecosystem | 30 | |
| 15532247739 | Evapotranspiration | Amount of water transpired by plants and evaporated from landscape | 31 | |
| 15532539377 | Transformed to Tundra | •Arctic Foxes introduced to Aleutian and Pribilof islands by fur industry •Breeding seabird colonies were decimated •Reduction in guano deposition resulted in a shift from nutrient demanding grasses and sedges to tundra vegetation more tolerant of nutrient poor soils | 32 | |
| 15532554990 | energy flow and chemical cycling | Regardless of an ecosystem's size, its dynamics involve two main processes: | 33 | |
| 15532559663 | Energy; Matter | ____ flows through ecosystems, while ____ cycles within them. | 34 | |
| 15532569330 | Conservation of Energy | •The first law of thermodynamics states that energy cannot be created nor destroyed, only transformed •Energy enters an ecosystem as solar radiation, is conserved, and is lost from organisms as heat |  | 35 |
| 15532578726 | second law of thermodynamics | •every exchange of energy increases the entropy of the universe •In an ecosystem, energy conversions are not completely efficient, and some energy is always lost as heat •On average 90% of energy lost between trophic levels | 36 | |
| 15532593923 | Autotrophs | build molecules themselves using photosynthesis or chemosynthesis as an energy source | 37 | |
| 15532593924 | Heterotrophs | depend on the biosynthetic output of other organisms | 38 | |
| 15532604826 | Energy and Nutrients | •pass from primary producers (autotrophs) to primary consumers (herbivores) to secondary consumers (carnivores) to tertiary consumers (carnivores that feed on other carnivores) •Foodchain à Food(trophic) pyramid |  | 39 |
| 15572836023 | Highest Productivity | •Tropical rain forests, estuaries, and coral reefs are among the most productive ecosystems per unit area •Marine ecosystems are relatively unproductive per unit area but contribute much to global net primary production because of their size | 40 | |
| 15572843447 | Primary Production in Aquatic Ecosystems | •In marine and freshwater ecosystems, both light and nutrients control primary production •Light Limitation •Depth of light penetration affects primary production in the photic zone of an ocean or lake |  | 41 |
| 15572866462 | Primary Production in Terrestrial Ecosystems | •In terrestrial ecosystems, temperature and moisture affect primary production on a large scale •Primary production increases with moisture | 42 | |
| 15572874041 | Evapotranspiration | •the water transpired by plants and evaporated from a landscape •It is affected by precipitation, temperature, and solar energy •It is related to net primary production |  | 43 |
| 15572890572 | Nutrient Limitations and Adaptations That Reduce Them | •On a more local scale, a soil nutrient is often the limiting factor in primary production •In terrestrial ecosystems, nitrogen is the most common limiting nutrient •Phosphorus can also be a limiting nutrient, especially in older soils |  | 44 |
| 15572899339 | Adaptations to Access Nutrients | •Various adaptations help plants access limiting nutrients from soil -Some plants form mutualisms with nitrogen-fixing bacteria -Legumes + Rhizobium bacteria -Alder + Frankia -Many plants form mutualisms with mycorrhizal fungi; these fungi supply plants with phosphorus and other limiting elements -Roots have root hairs that increase surface area -Many plants release enzymes that increase the availability of limiting nutrients | 45 | |
| 15572936625 | Invertebrates have highest efficiencies | •Birds and mammals have efficiencies in the range of 1-3% because of the high cost of endothermy •Fishes have production efficiencies of around 10% •Insects and microorganisms have efficiencies of 40% or more |  | 46 |
| 15572957320 | Aquatic Ecosystems have Inverted Biomass Pyramids | •Certain aquatic ecosystems have inverted biomass pyramids: producers (phytoplankton) are consumed so quickly that they are outweighed by primary consumers •Turnover time is the ratio of the standing crop biomass to production | 47 | |
| 15572988968 | Decomposition and Nutrient Cycling Rates | •Decomposers (detritivores) play a key role in the general pattern of chemical cycling •Rates at which nutrients cycle in different ecosystems vary greatly, mostly as a result of differing rates of decomposition •The rate of decomposition is controlled by temperature, moisture, and nutrient availability | 48 | |
| 15572996328 | Decomposition Rates | •Rapid decomposition results in relatively low levels of nutrients in the soil -For example, in a tropical rain forest, material decomposes rapidly, and most nutrients are tied up in trees and other living organisms •Cold and wet ecosystems store large amounts of undecomposed organic matter as decomposition rates are low •Decomposition is slow in anaerobic muds | 49 | |
| 15573001405 | Case Study: Nutrient Cycling in the Hubbard Brook Experimental Forest | •The Hubbard Brook Experimental Forest has been used to study nutrient cycling in a forest ecosystem since 1963 •The research team constructed a dam on the site to monitor loss of water and minerals •They found that 60% of the precipitation exits through streams and 40% is lost by evapotranspiration | 50 | |
| 15573008146 | Deforestation and Nitrogen Loss | •In one experiment, a watershed was clear-cut to determine the effects of the loss of vegetation on drainage and nutrient cycling •Net losses of water were 30-40% greater in the deforested site than the undisturbed (control) site •Nutrient loss was also much greater in the deforested site compared with the undisturbed site -For example, nitrate levels increased 60 times in the outflow of the deforested site •These results showed that nutrient loss in a forest ecosystem is controlled mainly by plants |  | 51 |
| 15573018400 | Restoration ecologists return degraded ecosystems to a more natural state | •Given enough time, biological communities can recover from many types of disturbances •Restoration ecology seeks to initiate or speed up the recovery of degraded ecosystems •The long-term objective of restoration is to return an ecosystem as much as possible to its predisturbance state •Two key strategies are bioremediation and augmentation of ecosystem processes | 52 |
