WORKSHEET: THE BIOSPHERE

1. Global Air Circulation Patterns A. Climate and Temperature Zones

1. __________________ means average weather conditions, such as temperature, humidity, wind speed, cloud cover, and rainfall, over time.

a. __________________________ is absorbed by ozone and oxygen in the upper atmosphere.b. Clouds, dust, and water vapor in the __________ absorb and reflect solar radiation.c. Radiation warms the earth’s surface and generates heat that drives the earth’s__________ systems.

2. The sun ______________ heats equatorial and polar regions, creating the world’s major temperature zones.

a. Warm_______________ air rises, cools, releases its moisture, and spreads northward and southward where it descends at 30o latitudes as very dry air (results in deserts).b. The air is warmed again and _______________ at 60o latitudes; as it moves toward the poles, regional areas receive varying amounts of _______________ that in turn influence ecosystems.

3. Seasonal variations in climate result from the earth’s ________________around the sun.

a. The amount of_________________radiation reaching the earth’s surface changes in the

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Northern and Southern hemispheres; this results in seasonal changes in climate.b. In temperate regions, organisms respond most to changes in ________________ and temperature; in deserts and tropical regions, they respond more to _____________________ changes in rainfall.

4. Latitudinal and seasonal variations in solar_______________ cause ocean water to warm and cool on a vast scale.

a. ________________ tend to move from the equator to the poles, warming the air above.b. _________________ form because of the earth’s rotation, winds, variations in temperature, and distribution of land masses.c. Immense _____________ water movements in the Atlantic and Pacific Oceans influence the distribution of ecosystems.

B. Harnessing the Sun and Wind 1. ____________________ energy is an attractive technology because it depends on a renewable energy source—the sun.2. _________________________ produce an electric current that splits water into oxygen and hydrogen gas, which can be used directly as fuel or to produce electricity.3. Where winds travel faster than ____________ meters per second, wind turbines are cost-effective producers of electricity.4. Because winds do not blow on a regular schedule________________cannot be the exclusive source of energy.

2. Air Circulation Patterns and Human AffairsA. A Fence of Wind, and Ozone Thinning

1. _____________________ in the lower stratosphere absorbs most of the ultraviolet radiation from the sun.

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a. Seasonal _____________ thinning occurs over Antarctica.b. With less ozone, more _________________ reaches the earth causing more skin cancers, cataracts, and weakened immune systems.

2. _____________________________ seem to be the cause—one chlorine atom can convert 10,000 ozone molecules to oxygen.

a. Winds rotate around the poles for most of the winter like a ________________________.b. _______________ molecules are split apart on “platforms” of ice crystals in fenced-in clouds.

B. No Wind, Lots of Pollutants, and Smog1. _________________ can trap pollutants close to the ground. 2. _________________ is gray air found in industrial cities that burn fossil fuel.3. _______________ is brown air found in large cities in warm climates; the key culprit is nitric oxide.

C. Winds and Acid Rain1. Burning _______________ in power plants produces sulfur dioxides.2. Burning ________________ and using nitrogen-rich fertilizers result in nitrogen oxides.3. Tiny particles of these oxides can fall to the earth in two forms: ____________ deposition or acid rain.

3. The Ocean, Landforms, and ClimatesA. Ocean Currents and Their Effects

1. Ocean water covers almost ___________________ of the earth’s surface.2. Latitudinal and seasonal variations in _______________ heating cause ocean water to warm and cool on a vast scale.

a. _________________ waters tend to move from the equator to the poles, warming the air above.

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b. Currents form because of the earth’s rotation, winds, variations in temperature, and distribution of land masses.

3. Immense _________________ water movements in the Atlantic and Pacific Oceans influence climate zones and the distribution of ecosystems.

B. Rain Shadows and Monsoons1. ___________________ refers to physical features of a region, such as elevation.2. Mountains, valleys, and other features influence__________________ climates.

a. The mountains of the western United States cause the winds from the ocean to rise, cool, and lose their ______________________.b. As the winds descend on the ______________ (eastern) slopes, they are devoid of moisture, causing a rain shadow effect.c. _______________ rains occur when warm winds pick up ocean moisture and release it over the cooler landmasses of Asia and Africa.

4. Realms of BiodiversityA. Plants and animals show a great diversity from one

global region to another.1. Climatic factors determine patterns of vegetation and why unrelated species may have similar _____________.2. _______________________ is the study of the global distribution of species.

B. The earth’s surface has been divided into regions for easier study.

1. _____________________ are very broad land regions with characteristic types of plants and animals; there are six of these.2. Biomes are large vegetational subdivisions including all animals and other organisms.

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a. _____________ distribution corresponds with climate, topography, and soil type.b. The form of the dominant ______________ tells us something of the weather conditions.

3. Hot spots and ______________ are portions of biomes that are vulnerable to species losses and possible extinction.

5. Moisture-Challenged BiomesA. Deserts, Natural and Man-Made

1. Most deserts lie between ____ north and south latitudes.

a. Annual rainfall is less than ______ centimeters.b. Vegetation is scarce, but there is some diversity; day/night temperatures __________ widely.

2. _______________________ is the conversion of grasslands and croplands to desert-like conditions.

a. The term also applies when ________________productivity drops by ten percent or more.b. At least _________________ square kilometers are being converted annually.c. Large-scale _________________ is caused by overgrazing of cattle (nonnative) on marginal lands.

B. Dry Shrublands, Dry Woodlands, and Grasslands1. Dry _____________ prevail when rainfall is less than 25–60 cm (for example, the highly flammable California chaparral).

a. The climate is semiarid.b. Rains occur during mild winter months; summers are long, hot, and dry; and dominant plants have tough, ___________________ leaves.

2. Dry ______________ occur when rainfall is about 40–100 cm; there are trees but not in dense forests.

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3. Grasslands sweep across much of the interior of continents, in the zones between deserts and temperate forests.

a. Characteristics include: flat or rolling land, high rates of evaporation, limited rainfall, grazing and burrowing animals, and __________________.b. There are two basic types in North America.

1) ________________ of the American Midwest is typified by short, drought-resistant grasses that have been replaced by grains that require irrigation.2) ___________________ was originally found in the American West where water was more plentiful.

c. The African ______________ are hot, dry and bear small bushes among the grass.

6. More Rain, More TreesA. Broadleaf Forests

1. Evergreen _________________ occur between 20o N and S latitude.

a. Most typical is the ______________________ forest where temperatures, rainfall, and humidity are all high.b. Plant growth is _________________, with competing vines; there is incredible animal diversity.

2. _________________ broadleaf forests are common at temperate latitudes.

a. In the _______________ forest, many trees drop some or all of their leaves during the pronounced dry season.b. In the __________________ forests of North America, conditions of temperature and rainfall do not favor rapid decomposition; thus, nutrients are conserved to provide fertile soil.

B. Coniferous Forests

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1. The typical “tree” in these forests is some variety of evergreen _______________ needlelike leaves.2. These forests are found in widely divergent geographic areas.

a. _______________ (or taiga) are found in the cool to cold northern regions of North America, Europe, and Asia; spruce and balsam fir are dominant.b. ______________coniferous forests extend southward through the great mountain ranges; fir and pine dominate.c. ______________ pine forests grow in the sandy soil of several Atlantic and Gulf coast states.

7. Brief Summers and Long, Icy WintersA. _______________ lies to the north of the boreal forests;

it is a vast treeless plain, very cold, with low moisture; it is characterized by permafrost, which prevents growth of large trees.

B. __________________ occurs at high elevations in mountains throughout the world.

8. Don’t Forget the Soils A. ___________ is a mixture of rock, mineral ions, and

organic matter.1. The size of the____________ can range from gravel to sand, silt, and clay.2. The organic matter, in variable stages of decomposition, is called _______________.

B. Soil _________________ are defined by the composition of soil from the surface downward.

1. Topsoil has the most humus and is the most _________________ to weathering.2. Loam ____________have the best mix of sand, silt, and clay for agriculture.

9. Freshwater ProvincesA. Lake Ecosystems

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1. A lake is a body of standing _________________ produced by geologic processes, as when an advancing glacier carves a basin in the earth.

a. The _____________________ extends from the shore to where rooted plants stop growing.b. The _______________ includes open, sunlit waters beyond the littoral to a depth where photosynthesis is no longer significant; plankton life is abundant.c. The _____________ is the deep, open water below the depth of light penetration; detritus sinks from the limnetic and is acted upon by decomposers.

2. Seasonal Changes in Lakesa. In temperate regions, lakes undergo changes in _________________ and temperature.b. In winter, ice (less dense) forms on the surface over water that is______________, much of it at 4o C (greatest density), and heavier.c. During the ____________________, warming and winds cause oxygen to be carried downward and nutrients to the surface.d. By midsummer, a _________________ between the upper warmer layers and lower cooler layers prevents vertical warming.e. During autumn, the upper layers cool and sink causing a __________________.

3. Trophic Nature of Lakesa. Glaciers carve out ________________, which become filled with water to form lakes.b. Interactions of soils, basin shape, and climate produce a continuum of ______________structure.c. _______________ lakes are deep, nutrient-poor, and low in primary productivity.d. ______________ lakes are shallow and nutrient-rich often due to agricultural and urban runoff wastes.

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B. Stream Ecosystems1. Streams start out as ______________ springs or seeps.2. Three kinds of habitats form along a continuum from head waters to river’s end.

a. ______________ are shallow, turbulent stretches where water flows swiftly over sand and rock.b. In ____________ deep water flows slowly over a smooth, sandy or muddy bottom.c. _____________ are fast-flowing waters with a smooth surface and a bottom of bedrock or rock and sand.

3. Several factors affect streams.a. Average ____________ and temperature are influenced by geography, altitude, and forest shade.b. ________________ and temperature vary with rainfall, snow melt, drought, and the seasons.c. Chemistry and pollution of the water depend on materials leached into, or added to, the stream.d. Streams _______________ their valleys and participate in cycles of erosion and redeposition of sediments and nutrients.

10. Life at Land’s EndA. Wetlands and the Intertidal Zone

1. ______________ are partially enclosed regions where fresh and saltwater meet.

a. Estuaries are incredibly _____________ feeding and breeding grounds for many animals.b. Many estuaries are declining because of upstream ______________________ of the freshwater that is necessary for their maintenance.

2. “____________________” refers to forests in sheltered regions along tropical coasts.

a. Ocean waves cannot reach these regions, so anaerobic sediments and mud ________________.

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b. _______________ plants with shallow, spreading roots abound here.c. The _______________ productivity of mangrove wetlands depends on the volume and flow rate of the water moving in and out with the tides.

B. Rocky and Sandy Coastlines1. The inhabitants of the __________________ are alternately exposed and submerged; existence is difficult.2. ______________shores have three vertically arranged zones.

a. The ______________ is submerged only during the highest possible lunar tide; it is sparsely populated.b. The ________________ is submerged during the regular tide and exposed at the lowest tide of the day.c. The __________________ is exposed only during the lowest lunar tide.

3. Sandy and muddy shores are rather unstable stretches of loose sediments; _______________ food webs occur; and invertebrates are plentiful.

C. Coral Reefs1. _____________________ are wave-resistant formations that consist of accumulated remains of marine organisms.2. Corals,________________, fishes, algae, and any many other organisms live in a delicate balance.

11. Coral BleachingA. Coral reefs are vast underwater complexes.

1. ___________________ live in the coral polyps, providing oxygen and recycling of nutrients.2. When corals are stressed, however, they expel their _________________.

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B. When corals die, only the hardened __________________ remain.

1. This is called coral _________________.2. It is on the rise all over the world, partly due to ______________ sea surface temperatures.

12. The Open OceanA. The world ocean has two vast provinces.

1. The _____________________ includes all the sediments and rocky formations of the ocean bottom; its zones begin with the continental shelf and extend downward to the deep-sea trenches.2. The _______________ includes the entire volume of ocean water and is subdivided into two zones.

a. The _____________ constitutes the relatively shallow water overlying the continental shelves.b. The _________________ is the water over the ocean basins; photosynthetic activity is restricted to the surface; and deeper food webs are dependent on marine snow—bits of organic matter that float downward.

B. Surprising Diversity1._______________ are the beginning of ocean food webs.

a. Organic remains and wastes enter the____________ webs.b. As much as __________________ of the productivity may be from microscopic ultraplankton.

2. Deeper ocean is too ____________ for photosynthesis.a. There, food webs start with _____________________, tiny bits of organic matter that drift down from communities above.b. Also, a number of species migrate ______________ to feed at night and move to the lower depths the next day.

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3. Hydrothermal vent ecosystems occur on the ocean floor.

a. Here, very cold water at the ocean bottom seeps into fissures, is heated, and then spewed forth mixed with ____________________.b. _______________________ bacteria provide the starting point for complex communities of tube worms, crustaceans, clams, and fishes.

C. Upwelling and Downwelling1. ____________ is the upward movement of deep, nutrient-rich water along the margins of continents.

a. Under the influence of northern winds and the earth’s rotation, water along the western coasts of the Northern Hemisphere move westward where cold, deep water moves in ________________ to replace it.b. At places where currents stir the ocean water and __________________ nutrients, primary pro-ductivity increases.

2. Every three to seven years, the warm surface waters of the western equatorial Pacific move eastward to the coasts of South and Central America to cause “____________”—a phenomenon known as _______________, which can affect weather patterns over land.

13. Applying Knowledge of the BiosphereA. An El Niño Southern Oscillation ______________ is

defined as changes in sea surface temperatures and in the air circulation patterns in the western equatorial Pacific Ocean.

1. _____________ ENSOs, the warm waters and heavy rains move westward; during an ENSO, prevailing winds “drag” surface waters eastward.2. This results in global ______________ on weather.

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B. The 1997–1998 El Niño episode caused a huge _______________in the populations of ocean photosynthesizers.

1. At the same time, the number of cases of ________________ in Peru increased dramatically.2. But where was the _______________ cause, Vibrio cholerae, reservoired between outbreaks?3. Rita Colwell discovered the answer: ________________, tiny crustaceans that live on phytoplankton, which increase/decrease with the warming/cooling of the ocean water.

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