110 terms

Envionmental Science

Tier 6, Ch 13-15
STUDY
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Agrobiodiversity
the world's genetic variety of animals and plants used to provide food
Agroforestry
Planting trees and crops together.
Alley Cropping
Planting of crops in strips with rows of trees or shrubs on each side.
Aquaculture
Growing and harvesting of fish and shellfish for human use in freshwater ponds, irrigation ditches, and lakes, or in cages or fenced-in areas of coastal lagoons and estuaries. See fish farming, fish ranching.
Artificial Selection
selective breeding of domesticated plants and animals to produce offspring with desired genetic traits
Biological Pest Control
Control of pest populations by natural predators, parasites, or disease-causing bacteria and viruses (pathogens).
Broad-Spectrum Agents
Pesticides that are toxic to many species.
Cash Crops
crops produced in large quantities to be sold or traded
Compost
Partially decomposed organic plant and animal matter used as a soil conditioner or fertilizer.
Conservation-Tillage Farming
Crop cultivation in which the soil is disturbed little (minimum-tillage farming) or not at all (no-till farming) to reduce soil erosion, lower labor costs, and save energy. Compare conventional-tillage farming.
Contour Farming
Plowing and planting across the changing slope of land, rather than in straight lines, to help retain water and reduce soil erosion.
Crop Rotation
Planting a field, or an area of a field, with different crops from year to year to reduce soil nutrient depletion. A plant such as corn, tobacco, or cotton, which removes large amounts of nitrogen from the soil, is planted one year. The next year a legume such as soybeans, which adds nitrogen to the soil, is planted.
DDT
Dichlorodiphenyltrichloroethane, a chlorinated hydrocarbon that has been widely used as a pesticide but is now banned in some countries.
Desertification
Conversion of rangeland, rain-fed cropland, or irrigated cropland to desertlike land, with a drop in agricultural productivity of 10% or more. It usually is caused by a combination of overgrazing, soil erosion, prolonged drought, and climate change.
Famine
Widespread malnutrition and starvation in a particular area because of a shortage of food, usually caused by drought, war, flood, earthquake, or other catastrophic events that disrupt food production and distribution.
Feedlots
Places where livestock are concentrated in a very small area and raised on hormones and hearty grains that prepare them for slaughter at a much more rapid rate than grazing; often referred to as factory farms.
Fishery
Concentrations of particular aquatic species suitable for commercial harvesting in a given ocean area or inland body of water.
Fish-Farming
Form of aquaculture in which fish are cultivated in a controlled pond or other environment and harvested when they reach the desired size. See also fish ranching.
Fish-Ranching
Form of aquaculture in which members of a fish species such as salmon are held in captivity for the first few years of their lives, released, and then harvested as adults when they return from the ocean to their freshwater birthplace to spawn.
Green Manure
Freshly cut or still-growing green vegetation that is plowed into the soil to increase the organic matter and humus available to support crop growth. Compare animal manure.
Green Revolution
Popular term for introduction of scientifically bred or selected varieties of grain (rice, wheat, maize) that, with high enough inputs of fertilizer and water, can greatly increase crop yields.
Genetically Modified Food
food whose genes have been altered to make them grow bigger or faster or more resistant to pests
Herbicides
Kills weeds by disrupting metabolism and growth
High-Input Agriculture
same as industrialized agriculture.
Industrialized Agriculture
Using large inputs of energy from fossil fuels (especially oil and natural gas), water, fertilizer, and pesticides to produce large quantities of crops and livestock for domestic and foreign sale. Compare subsistence farming.
Integrated Pest Management
Combined use of biological, chemical, and cultivation methods in proper sequence and timing to keep the size of pest population below the size that causes economically unacceptable loss of crop or livestock.
Intercropping
Growing two or more different crops at the same time on a plot. For example, a carbohydrate-rich grain that depletes soil nitrogen and a protein-rich legume that adds nitrogen to the soil may be intercropped.
Interplanting
Simultaneously growing a variety of crops on the same plot. See agroforestry, intercropping, polyculture, polyvarietal cultivation.
Macronutrients
Carbohydrates, fats, and proteins, which are necessary for building and maintaining body tissues and providing energy for daily activities
Malnutrition
Faulty nutrition, caused by a diet that does not supply an individual with enough protein, essential fats, vitamins, minerals, and other nutrients needed for good health.
Monoculture
The cultivation of a single crop on a farm or in a region or country; a single, homogeneous culture without diversity or dissension
Organic Fertilizer
Organic material such as animal manure, green manure, and compost, applied to cropland as a source of plant nutrients. Compare commercial inorganic fertilizer.
Overnutrition
Diet so high in calories, saturated (animal) fats, salt, sugar, and processed foods and so low in vegetables and fruits that the consumer runs high risks of diabetes, hypertension, heart disease, and other health hazards. Compare malnutrition, undernutrition.
Persistence
The length of time they remain deadly in the environment.
Pest
Unwanted organism that directly or indirectly interferes with human activities.
Pesticides
a general term for chemicals that are used to eliminate pests, such as insecticides that kill insects and herbicides that kill weeds
Pheremones
Sex attractants can lure pests into traps or attract their natural predators into crop fields.
Polyculture
Complex form of intercropping in which a large number of different plants maturing at different times are planted together. See also intercropping. Compare monoculture, polyvarietal cultivation.
Polyvarietal Cultivation
Planting a plot of land with several varieties of the same crop. Compare intercropping, monoculture, polyculture.
Rachel Carson
United States biologist remembered for her opposition to the use of pesticides that were hazardous to wildlife (1907-1964)
Salinization
Accumulation of salts in soil that can eventually make the soil unable to support plant growth.
Shelterbelts
Rows of trees planted to prevent wind/water erosion of soil -
Great Green Wall of China
Soil Conservation
Methods used to reduce soil erosion, prevent depletion of soil nutrients, and restore nutrients already lost by erosion, leaching, and excessive crop harvesting.
Soil Erosion
Movement of soil components, especially topsoil, from one place to another, usually by wind, flowing water, or both. This natural process can be greatly accelerated by human activities that remove vegetation from soil.
Strip Cropping
Planting regular crops and close-growing plants, such as hay or nitrogen-fixing legumes, in alternating rows or bands to help reduce depletion of soil nutrients.
Terracing
Planting crops on a long, steep slope that has been converted into a series of broad, nearly level terraces with short vertical drops from one to another that run along the contour of the land to retain water and reduce soil erosion.
Traditional Intensive Agriculture
Producing enough food for a farm family's survival and perhaps a surplus that can be sold. This type of agriculture uses higher inputs of labor, fertilizer, and water than traditional subsistence agriculture. See traditional subsistence agriculture. Compare industrialized agriculture.
Traditional Subsistence Agriculture
Production of enough crops or livestock for a farm family's survival and, in good years, a surplus to sell or put aside for hard times. Compare industrialized agriculture, traditional intensive agriculture.
Aral Sea
A lake lying between Kazakhstan and Uzbekistan that has lost 80% of its surface area from irrigation projects.
Aquifers
porous, water-saturated layers of sand, gravel, or bedrock that can yield an economically significant amount of water
Center-Pivot Low-Pressure Sprinklers
Uses pumps to spray water on crops
Channelization
An engineering technique to straighten, widen, deepen, or otherwise modify a natural stream channel.
Desalination
Purification of salt water or brackish (slightly salty) water by removal of dissolved salts.
Drainage Basin
See Watershed
Drip irrigation system
delivers small amount of water directly to plants' roots
Flood Irrigation
involves flooding of a crop, 40% of water is lost
Floodplain
Flat valley floor next to a stream channel. For legal purposes, the term often applies to any low area that has the potential for flooding, including certain coastal areas.
Gray Water
all of the wastewater that drains from washing machines, sinks, dishwashers, tubs or showers and can be reused for non-sanitary purposes
Groundwater
water that fills the cracks and spaces in underground soil and rock layers.
Land Subsidence
The gradual sinking of land. The condition may result from the removal of groundwater or oil, which is frequently instrumental in supporting the overlying rock and soil.
Natural Recharge
Natural replenishment of an aquifer by precipitation, which percolates downward through soil and rock. See recharge area.
Ogallala Aquifer
world's largest aquifer; under parts of Wyoming, South Dakota, Nebraska, Kansas, Colorado, Oklahoma, New Mexico, and Texas (the Midwest). Holds enough water to cover the U.S. with 1.5 feet of water. Being depleted for agricultural and urban use.
Reverse Osmosis
the process occurring when the external pressure on a solution causes a net flow of solvent through a semipermeable membrane from the solution to the solvent.
Surface Runoff
Water flowing off the land into bodies of surface water. See reliable runoff.
Three Gorges Dam
A dam built across the Yangtze River that displaced over 1.5 million people during its construction. It is one of the largest dams in the world
Water Table
the upper surface of the zone of saturation
Watershed
Land area that delivers water, sediment, and dissolved substances via small streams to a major stream (river).
Xeriscaping
a method of landscaping that uses plants that are well adapted to the local area and are drought resistant, reduces water useage.
Zone Of Saturation
Area where all available pores in soil and rock in the earth's crust are filled by water. See water table, zone of aeration.
Acid Mine Drainage
Pollution caused when sulfuric acid and dangerous dissolved materials such as lead, arsenic, and cadmium wash from coal and metal mines into nearby lakes and streams.
Area Strip Mining
Type of surface mining used where the terrain is flat. An earthmover strips away the overburden, and a power shovel digs a cut to remove the mineral deposit. After removal of the mineral, the trench is filled with overburden, and a new cut is made parallel to the previous one. The process is repeated over the entire site. Compare dredging, mountaintop removal, open-pit mining, subsurface mining.
Biomimicry
the examination of nature, its models, systems, processes, and elements to emulate or take inspiration from in order to solve human problems.
Brownfields
abandoned industrial and commercial sites that are contaminated with hazardous wastes
Biological Weathering
Any weathering that's caused by the activities of living organisms
Chemical Weathering
The process that breaks down rock through chemical changes
Continental Crust
the portion of the earth's crust that primarily contains granite, is less dense than oceanic crust, and is 20 to 50 kilometers thick
Contour Strip Mining
Form of surface mining used on hilly or mountainous terrain. A power shovel cuts a series of terraces into the side of a hill. An earthmover removes the overburden, and a power shovel extracts the coal, with the overburden from each new terrace dumped onto the one below. Compare area strip mining, dredging, mountaintop removal, open-pit mining, subsurface mining.
Convergent Plate Boundary
Area where earth's lithospheric plates are pushed together. See subduction zone. Compare divergent plate boundary, transform fault.
Core
Inner zone of the earth. It consists of a solid inner core and a liquid outer core. Compare crust, mantle.
Crust
Solid outer zone of the earth. It consists of oceanic crust and continental crust.
Divergent Plate Boundary
Area where earth's lithospheric plates move apart in opposite directions. Compare convergent plate boundary, transform fault.
Fossil Fuels
Combustible materials such as oil, coal and natural gas that are composed of the remains of formerly living material
Geology
Study of the earth's dynamic history. Geologists study and analyze rocks and the features and processes of the earth's interior and surface.
Glaciers
a large mass of sloving ice and snow that carves new features and deposits sediments
High-Grade Ore
Ore that contains a fairly large amount of the desired mineral.
Igneous Rock
Rock formed when molten rock material (magma) wells up from the earth's interior, cools, and solidifies into rock masses.
Lithosphere
Outer shell of the earth, composed of the crust and the rigid, outermost part of the mantle outside the asthenosphere; material found in earth's plates. See crust, mantle.
Low-Grade Ore
Ore that contains a smaller amount of the desired mineral.
Mantle
the layer of rock between the earth's crust and core
Mass Wasting
the downslope movement of rock, regolith, and soil under the direct influence of gravity
Metamorphic Rock
Rock produced when a preexisting rock is subjected to high temperatures (which may cause it to melt partially), high pressures, chemically active fluids, or a combination of these agents. Compare igneous rock, sedimentary rock. See rock cycle.
Mineral
a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition
Mountaintop Removal
Type of surface mining that uses explosives, massive shovels, and even larger machinery called draglines to remove the top of a mountain to expose seams of coal underneath a mountain. Compare area strip mining, contour strip mining.
Oceanic Crust
the portion of Earth's crust that is usually below the oceans and not associated with continental areas, thinner and higher in density that continental crust and basaltic rather than granitic in composition
Open-Pit Mining
Removing minerals such as gravel, sand, and metal ores by digging them out of the earth's surface and leaving an open pit. Compare area strip mining, contour strip mining, dredging, mountaintop removal, subsurface mining.
Ore
Part of a metal-yielding material that can be economically and legally extracted at a given time. An ore typically contains two parts: the ore mineral, which contains the desired metal, and waste mineral material (gangue).
Overburden
Layer of soil and rock overlying a mineral deposit. Surface mining removes this layer.
Rock
Any material that makes up a large, natural, continuous part of the earth's crust.
Rock Cycle
Largest and slowest of the earth's cycles, consisting of geologic, physical, and chemical processes that form and modify rocks and soil in the earth's crust over millions of years.
Sedimentary Rock
Rock that forms from the accumulated products of erosion and in some cases from the compacted shells, skeletons, and other remains of dead organisms.
Smelting
Process in which a desired metal is separated from the other elements in an ore mineral.
Spoils
Unwanted rock and other waste materials produced when a material is removed from the earth's surface or subsurface by mining, dredging, quarrying, and excavation.
Strip Mining
Form of surface mining in which bulldozers, power shovels, or stripping wheels remove large chunks of the earth's surface in strips. See area strip mining, contour strip mining, surface mining. Compare subsurface mining.
Subduction
the process by which oceanic crust sinks beneath a deep ocean trench and back into the mantle at a convergent plate boundary
Subsurface Mining
Extraction of a metal ore or fuel resource such as coal from a deep underground deposit. Compare surface mining.
Surface Mining
Removing soil, subsoil, and other strata and then extracting a mineral deposit found fairly close to the earth's surface. See area strip mining, contour strip mining, dredging, mountaintop removal, open-pit mining. Compare subsurface mining.
Tailings
Piles of loose rock produced when a mineral such as uranium is mined and processed (extracted and purified from the ore)
Tectonic Plates
Various-sized areas of the earth's lithosphere that move slowly around with the mantle's flowing asthenosphere. Most earthquakes and volcanoes occur around the boundaries of these plates.
Transform Fault
Area where the earth's lithospheric plates move in opposite but parallel directions along a fracture (fault) in the lithosphere.
Weathering
Physical and chemical processes in which solid rock exposed at earth's surface is changed to separate solid particles and dissolved material, which can then be moved to another place as sediment.