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68 Cards in this Set
- Front
- Back
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On average, only about________ percent of Earth’s surface is suitable for agriculture without any physical constraints
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3.5 Percent
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The Green Revolution was a 30-year transformation of agriculture in developing regions that started in the 1940s, and involved...
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the distribution of high-yielding crop varieties, synthetic fertilizer, irrigation, and pesticides to subsistence farmers in Asia and Latin America
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World food production has kept up with ________ and_________ have occurred especially in the past 50 years
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rapid population growth; dramatic gains
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Large-scale agriculture has ________ global biodiversity
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increased
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Rachel Carson’s 1962 book Silent Spring drew...
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wide-scale public attention to the environmental effects of pesticides
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Planting large holdings of one or a few crop varieties that have been developed for high yields is referred to as _________
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monoculture
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Which of the following are basic limits to how much of Earth’s surface can be used for agriculture?
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-Temperature
-Topography -Climate -Soil Quality |
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__________ is the biggest limit on agricultural productivity.
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Drought
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Transpiration is the movement of ________ from soil to the atmosphere through the bodies of plants.
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water
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examples of organochlorine pesticides
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DDT, Aldrin, Dieldrin, Heptachlor
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Permeability
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how readily the medium transmits water, based on the size and shape of the open spaces it contains and how interconnected the spaces are.
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Under natural conditions many aquifers are _______, which is a term that means the water the aquifer holds is under pressure, so water will flow to the surface from a well without pumping.
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artesian
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___________ pollution consists of diffuse, non-bounded discharges from many contributors, such as runoff from city streets or agricultural fields, so it is more challenging to control.
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Non-point
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Some types of pollution can create ________areas ("dead zones"), where dissolved oxygen levels are too low to support marine life—typically less than two to three milligrams per liter.
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hypoxic
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Water pollution is relatively easier to control when it comes from a _____________ source which is defined as a distinct, limited discharge source such as a factory, which can be required to clean up or reduce its effluent.
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point
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The global water cycle consists of 3 basic steps
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precipitation, movement of water through above and below the land surface to oceans, and evaporation or transpiration back to the atmosphere.
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Confined Aquifers
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capped by an impermeable layer and are less likely to be contaminated from surface contaminants.
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Hydrogeologists use a quantity called __________ (essentially the height of the water) to explain why groundwater moves from one place to another.
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the hydraulic head
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Supplies of freshwater (water without a significant salt content) exist because....
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precipitation is greater than evaporation on land
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Salinity is not dangerous to humans, but water becomes non-potable for humans consumption at around....
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250 mg/l
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__________will reduce the rate at which species colonize new areas because they have trouble crossing gaps in between the smaller sections of remaining habitat.
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Habitat fragmentation
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Extinctions are occurring today at an exceptionally __________, and ____________ are a major cause.
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high rate; human activites
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Estimates suggest that at least __________ species remain to be catalogued.
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5 to 15 million
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Out of a total of _____ hotspots around the globe,_____ are located on __________.
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34; 3; U.S territory
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Warming associated with __________ is shrinking __________.
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global climate change; Arctic sea ice coverage
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According to the Food and Agriculture Organization (FAO), about ____________ of ocean fish stocks are being exploited close to their maximum sustainable limits.
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Half
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Based on fossil records and the opinions of experts who study various groups of living organisms, biodiversity on Earth appears to be at a historical peak __________.
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Today
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Conservation International defines hotspots as regions that have at least 1,500 species of vascular plants that are ____________(found only in that area) and that have lost at least 70 percent of their original habitat.
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endemic
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Land can become less suitable as habitat even if it is not directly converted to other uses when actions such as suburban development and road-building carve large sectors of land into fragments, and the undeveloped parcels may be too small or isolated to support viable populations of species that thrived in the larger ecosystems. This process is called _________.
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habitat fragmentation
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Most endangered species are threatened by multiple factors, but ___________ is generally viewed as the largest single cause of biodiversity loss worldwide.
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habitat loss
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Species richness
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The number of species in a given habitat, or worldwide
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hotspots
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areas especially rich in biodiversity
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edge effects
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impacts that stem from the juxtaposition of two different ecosystems-- for example a meadow and a paved street.
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Many alternative sources of energy, such as wind, solar, and hydropower, are ___________ because their supplies are refreshed faster than humans consume them.
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renewable resources
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The __________(inflow minus outflow) determines whether the stock grows, shrinks, or remains constant.
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net flow rate
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__________, also known as ethyl alcohol or grain alcohol, can be fermented from sugars found in corn and other crops and added to conventional gasoline.
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Ethanol
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he combination of a source rock, reservoir, trap, and cap rock, which comprise all the essential geologic elements that must be in place to yield large oil or gas field, is called a __________ system.
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hydrocarbon
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_________ is the first fossil fuel exploited by humans for energy on a large scale, is a carbonaceous rock formed from buried plants in ancient forests or swamps.
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Coal
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Analysts generally agree that, at best, corn ethanol offers __________ over gasoline, and that the real promise lies in making ethanol from cellulosic (woody) plants such as switchgrass, willows, and poplars.
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modest energy savings
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__________ tap our planet's natural radioactive energy and the fact that temperature and pressure inside Earth __________ with depth.
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Geothermal power systems; increase
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Anthracite coals are characteristically ____________ and represent the most important coal grade for energy production.
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metallic gray
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__________cells, the type commonly seen on homes and commercial buildings, use __________such as silicon to produce electricity from sunlight.
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Photovoltaic (PV); semi-conducting materials
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Traditional fossil fuels (i.e. oil, natural gas and coal) account for roughly __________ of world energy use.
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80 percent
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non-renewable resource
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A natural resource such as coal or mineral ores that is not replaceable after its removal. fossil fuels
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stock
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The amount of material in a certain deposit or reservoir
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Flow
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the rate at which new material is added to stock or removed from stock.
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_____, _____, and _____, the traditional fuels that have powered modern cities since the industrial revolution, still are dominant.
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Oil, natural gas, and coal
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Tar sands
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deposits of oil too think to flow
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oil shales
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tight rock source rocks that are not permeable enough to pump out oil directly.
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fissile material
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elements whose atoms can be split by thermal (slow) neutrons.
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Large scale agriculture has
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-Reduced biodiversity
-Fragmented natural resources -Diverted or polluted fresh water resources -Altered nutrient balance of ecosystems |
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only ____ of Earth's surface is suitable for agriculture
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3.5%
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Stomata
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Tiny openings or pores, found mostly on the under-surface of a plant leaf. and used for gas exchange.
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Transpiration
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The evaporation of water from aerial parts of plants
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Harvest Index
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the ratio to grain wheat to total plant weight
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3 steps to water cycle
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-precipitation
-travels to oceans -evaporation |
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Freshwater is only ___ of water supply
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6%
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Early photosynthetic bacteria appeared about ______ years ago
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3.5 billion
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3 classifications of life on earth
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Eukarya
bacteria Achaea |
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_____ of earth's energy is produced from biomass
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11%
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4 types of process affect air pollution levels
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-Emissions
-chemistry -Transport -Depostion |
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Primary pollutants
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ones that are pumped into the air
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Secondary pollutants
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not directly emitted but formed by other pollutants
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Aerosols
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Liquid or solid particles that are suspended in air or in gas
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smog
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smoke or fog pollution
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Acid rain
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Rainfall with greater acidity than usual
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chloroflourocarbons
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Any of several organic compounds composed of carbon, fluorine, chlorine, and hydrogen. used in refrigerants
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photovoltaic
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producing an electric current as the result of light striking a metal; the direct conversion of radiant energy into electrical energy.
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