RNR chap 8 review

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RNR chap 8 review
2010-12-08 16:04:08
Living environment Chapter

Questions for living in the enviroment Chapter 9
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  1. What is a coral reef and why should we care about coral reefs? What is coral bleaching?
    • a form in clear warm costal waters of the tropics and subtropics, they are oen of the most productive ecosystems in terms of bbioderviserty and are the marine equlievent of tropical rain forests
    • coral bleaching occurs when stressed such as increased temperature causes the algae upon wich corals depend for food to die off leaviing behind a white skeleton of calcium carbonate
  2. What percentage of the earth’s surface is covered with water?
  3. What is an aquatic life zone?
    the equivalent of the terrestrial biomes we discussed in class
  4. Distinguish between a saltwater (marine) life zone and a freshwater life zone. What major types of organisms live in the top, middle, and bottom layers of aquatic life zones?
    • saltwater and freashwater life zones containe several major types of organisms, plankton is in the first group along with zooplankton drifint animals and ultra plaknkton which is responcible for 70% of primairy production near ocean surface
    • the second major type of roganissesm is nekton strongly swimming consumes third is benthos bottom dwellers and teh fourth is decomposers mostly bacteria that bring down orgainc compounds
  5. Define
    plankton and describe three types of plankton. Distinguish among nekton,
    benthos, and decomposers and give an example of each.
    • plankton is free floatin gwealky swimming that can devide into threee groups zooplankton consist of primary consumers that feed on photo plankton and ultraplankton these are small photosynthetic bacteria may be responcible for 70% of primary productivity near the ocean surface
    • nekton is strongly swimming consumers such as fish turtles benthos bottom dwellers clams worms, and decomposers are bactiers
  6. What five factors determine the types and numbers of organisms found in the three layers of aquatic life zones?
  7. What is turbidity, and how does it occur? Describe one of its harmful impacts.
    • when the water is clouded by excessive algal growth (algal blooms) resulting from nutrient overloads
    • it restricts photosysnthasis in coral reefs and negatively affects primary production and the abundance of animals in freshwater and marine systems
  8. What major ecological and economic services are provided by marine systems? What are the three major life zones in an ocean?
    • Marine systems are divided into 3 major life zones; the coastal zone is the nutrient-rich area between the high tide mark and the edge of the continental shelf.
    • The open ocean is divided into the euphotic zone, the zone at the surface where considerable photosynthesis occurs, even though nutrient levels are low. Below this layer lies the bathyl zone, a dimly lit layer where many fishes and invertebrates live during the day (and move into the euphotic zone to feed at night). Below this is the abyssal zone, which is dark and cold, but supports a relatively high diversity of living organisms, even though there is no photosynthesis to support the food web
  9. Distinguish between an estuary and a coastal wetland and explain why have high net primary productivities.
    • estuaries are where rivers meet the sea, patially enclosed bodies of water where sea water mixes with freshwater as well as nutries and pollutants from streams, rivers and runoff from the land
    • costal wetlands are costal lands areas covered with water all or part of the yar include rivier monts, inlets, bays sounds and salt marshes in tempreate zones
  10. What is a mangrove forest and what is its ecological and economic importance?
    the tropical equalavent of salt marshes, they are found along some 70% of gently sloping sandy and silty coastlines in tropica and subtropica regions especically in southeast asia
  11. What is the intertidal zone? Distinguish between rocky and sandy shores. Why does the open sea have a low net primary productivity?
    • intertidal zone is the area of shoreline between low and high tides
    • rocky shores are pounded by waves , sandy shores have gently sloping barrier beatches that support other types of marine organism, most of them keep hiddne from view and survive by borrowing digging and tunneling in the sand
  12. Why does the open sea have a low net primary productivity?
    • the open sea is a sharp increase in water dept at the edge of the continetal shelf that sepreats the costal zone from the vast volume of the ocean, temperature chanes with dept and can beused to define zones what are primily developed on sunlight and as you go deeper sunlight dissappears
    • zoens are euphotic zone, bathyal zone and abyssal zone
  13. What human activities pose major threats to marine systems and to coral reefs?
    ocean warming, soil erosion alge growth from fertlizer runoff bleaching rising sea levels increased UV exposure damage from anchors damage from fishing and diving
  14. Explain why the Chesapeake Bay is an estuary in trouble. What is being done about some of its problems?
    • because of human activity, population growth it recieves wwastes from poin tand non point sources scattered throught a huge drangage basin that includes 9 large rivers, phosphate ant nitrate levels rose sharply primaryly sewage treatment platns and indistrual plants funoff of fertiliers and animal wastes from urban suaburban and agricultural land
    • the U.S. made the Chesapeak Bay progam an attempt at intergrated costal management there workign to reude pollution imputs into the bay, banning phospate detergents upgrading sewage treatment plants and monitoring industral discharge more closely and restoring wetlands
  15. What major ecological and economic services do freshwater systems provide?
  16. What is a lake?
    Lakes are large natural bodies of standing freshwater formed when precipitation, runoff, or groundwater seepage fills depressions in the earth’s surface.
  17. What four zones are found in most lakes?
    Lakes can be divided into distinct habitats, which include the littoral zone (from the shore to a depth where rooted aquatic plants will no longer grow), limnetic zone (beyond the littoral zone where photosynthesis occurs), profundal zone (below the limnetic zone, separated by the thermocline (remember from class, the layer of rapid temperature change caused by rapid warming of the surface in late spring during the annual lake mixing cycle?), and the benthic zone, or bottom layer.
  18. Distinguish among oligotrophic, eutrophic, hypereutrophic, and mesotrophic lakes.
    Lakes can be divided by productivity into oligotrophic (low nutrient levels, unproductive, many in mountainous areas), mesotrophic (moderately productive), eutrophic (very productive, often shallow and turbid), and hypereutrophic (excessive nutrients from cultural eutrophication, often with noxious algal blooms and low diversity of fishes and invertebrates in the lake).
  19. What is cultural eutrophication?
    Human inputs of nutrients from the atmosphere and from nearby urban and agricultural areas can accelerate the eutrophication of lakes,
  20. Define surface water, runoff, and watershed (drainage basin).
    percicipation that does not sink into the ground or evaporate is surface water, runoff is when it flows into a stream, watershed is is the land area that delivers runoff, sediment, and dissolved substances to a stream
  21. Describe the three zones that a stream passes through as it flows from mountains to the sea
    the source zone (high gradients because of steep terrain) in the mountains, the transition zone (intermediate gradients) in hilly country, and the floodplain zone (low elevations near the ocean); note how rivers meander as they move through the floodplain zone, not much gradient here, usually large, low velocity habitats.
  22. Describe the relationships between dams, deltas, wetlands, hurricanes, and flooding in New Orleans, Louisiana
    - the loss of coastal wetlands, barrier islands, and barrier beaches is resulting in increasing damage from coastal storms around the world, like Hurricane Katrina and NewOrleans in 2005.
  23. Give three examples of inland wetlands and explain the ecological importance of such wetlands
    Inland wetlands are lands covered with freshwater all or part of the time (excluding lakes, reservoirs, and streams) and located away from coastal areas. They include marshes (dominated by grasses and reeds with few trees), swamps (dominated by trees and shrubs), andprairie potholes (depressions carved out by ancient glaciers). Other examples are floodplains, which receive excess water during heavy rains and floods, and the wetarctic tundra in summer
  24. What are four ways in which human activities are disrupting and degrading freshwater systems?
    As with coastal systems, human activities are also degrading lakes, streams, and freshwater wetlands. Dams and canals fragment freshwater systems, destroying habitats, eliminating migratory fishes like salmon, and turning flowing systems into lakes. Flood control levees and dikes disconnect rivers and streams from their floodplains, which affects not only the stream, but also the floodplain habitat, whether it is terrestrial or aquatic. Pollution from farms, cities, and industries can affect primary productivity (both up and down) and kill or reduce the abundances of numerous aquatic species. Wetland destruction from farming and municipal development eliminates all of the ecosystem services that these ecosystems provide.
  25. Describe inland wetlands in the United States in terms of the area of wetlands lost and the resulting loss of ecological and economic services.
    • More than half of the inland wetlands estimated to have existed in the continental United States during the 1600s no longer exist. About 80% of lost wetlands were destroyed to grow crops. The rest were lost to mining, forestry, oil and gas extraction, highways, and urban development. The heavily farmed U.S. state of Iowa has lost about 99% of its original inland wetlands.
    • increased flood and drought damage in the United States—more examples of unnatural disasters
  26. How is the degradation of many of the earth’s coral reefs (Core Case Study) a reflection of our failure to follow the four scientific principles of sustainability? Describe this connection for each principle.