Environmental Biology Exam 3

Food security

Condition under which people have access to enough safe and nutritious food for a healthy and active lifestyle. Based on four pillars: availability

Food insecurity

Condition of living with chronic hunger and poor nutrition that threatens a healthy and active lifestyle. Root cause is poverty.

Chronic undernutrition (hunger)

Condition suffered by people who cannot grow or buy enough food to meet their basic energy needs. People live low on the food chain (mostly grains).

Chronic malnutrition

Condition in which people do not get enough protein and other key nutrients (vitamins and minerals)

Overnutrition

Condition where food energy intake exceeds energy use and causes excess body fat

Virtual water

Water used to produce food and other products

Industrialized agriculture (high-input agriculture)

Production of large quantities of crops and livestock using motorized equipment

Monoculture

Practice of producing a single crop at a time on a plot of land. Used in industrialized agriculture.

Polyculture

Practice of growing several crops on the same plot simultaneously

Organic agriculture

Growing crops without the use of synthetic pesticides

Green revolution

Dramatic increase in crop yields through the development and planting of monocultures of selectively bred or genetically engineered varieties of key grain crops (rice

Integrated pest management (IPM)

Use of a coordinated combination of cultivation techniques

Soil erosion

Movement of soil components

Desertification

Process in which the productive potential of topsoil falls by 10% or more due to a combination of prolonged drought and human activities such as overgrazing

Soil salinization

Gradual accumulation of salts in the upper soil layers from repeated applications of irrigation water in dry climates. Stunts crop growth and can eventually kill plants.

Waterlogging

Condition where water accumulates underground and gradually raises the water table

Agrobiodiversity

The genetic variety of animal and plant species used on farms to produce food. Since 1900

Concentrated animal feeding operations (CAFOs)

Industrialized factory farms that raise large numbers of animals bred to gain weight quickly

Aquaculture (fish farming)

Practice of raising fish

Water pollution

Any change in water quality that can harm living organisms or make the water unfit for human uses such as drinking

Point source

Single

Nonpoint source

Broad and diffuse areas where rainfall or snowmelt washes pollutants off the land into bodies of surface water (e.g.

Eutrophication

Natural nutrient enrichment of a shallow lake

Cultural eutrophication

Accelerated eutrophication from human inputs of nutrients through the atmosphere and from urban and agricultural areas (fertilizer runoff

Dead zone

Massive volume of water with a low dissolved-oxygen content (below 2 mg/L) that contains little or no animal marine life. Caused by eutrophication and algal bloom decomposition.

Watershed (drainage basin)

The land area that delivers runoff

Groundwater

Freshwater that sinks into the soil and is stored in slowly flowing and slowly renewed underground reservoirs called aquifers.

Aquifer

Underground body of rock (caverns and porous layers of sand

Water table

The top of the groundwater zone of saturation; fluctuates up and down depending on weather

Overpumping

Removing groundwater from an aquifer faster than it is replenished from rainfall and snowmelt. Leads to falling water tables

Subsidence

Sinking of land above an aquifer caused by the collapse of sand and rock that was held in place by water pressure. Can be sudden (sinkhole) or gradual.

Desalination

The process of removing dissolved salt from ocean water or from brackish (slightly salty) water in aquifers or lakes using distillation or reverse osmosis. Expensive and energy-intensive.

Drip (trickle) irrigation

The most efficient way to deliver small amounts of water precisely to crops using a network of perforated plastic tubing installed at or below ground level. Allows 90-95% of water to reach crops.

Gray water

Used water from bathtubs

Floodplain

The adjacent area where freshwater in a stream or river overflows its normal channel. Can be naturally flooded or affected by human activities.

Geology

The scientific study of dynamic processes that take place on the earth's surface and in its interior

Core

The earth's innermost zone

Mantle

The thick zone surrounding the earth's core

Crust

The outermost

Mineral

A naturally occurring chemical element or inorganic compound that exists as a solid with a regularly repeating internal arrangement of its atoms or ions (a crystalline solid). Examples: gold

Mineral resource

A concentration of one or more minerals in the earth's crust that is large enough to cover the cost of extracting and processing it into raw materials and useful products. Nonrenewable.

Rock

A solid combination of one or more minerals found in the earth's crust. Examples: granite (mica

Sedimentary rock

Rock made of sediments (dead plant and animal remains and tiny particles of weathered and eroded rocks) that have been compacted and cemented together. Examples: sandstone

Igneous rock

Rock formed below or on the earth's surface under intense heat and pressure when magma wells up from the earth's mantle and then cools and hardens. Examples: granite (underground)

Metamorphic rock

Rock formed when an existing rock is subjected to high temperatures

Rock cycle

The interaction of physical and chemical processes (erosion

Ore

Rock that contains a large enough concentration of a particular mineral (often a metal) to make it profitable for mining and processing. High-grade ore has high concentration; low-grade ore has low concentration.

Reserves

Identified deposits from which a usable mineral can be extracted profitably at current prices with current mining or extraction technology. Can be expanded with new discoveries

Depletion time

The time it takes to use up 80% of the available reserves of a nonrenewable resource at a given rate of use. Varies based on assumptions about recycling

Rare earth metals

17 elements including scandium

Surface mining

Method to remove shallow mineral deposits where vegetation

Open-pit mining

Type of surface mining where machines are used to dig very large holes and remove metal ores containing copper

Strip mining

Type of surface mining where mineral deposits that lie in large horizontal beds close to the earth's surface are extracted. Includes area strip mining (flat terrain) and contour strip mining (hilly terrain).

Mountaintop removal

Type of surface mining where explosives are used to remove the top of a mountain to expose seams of coal that are then extracted. Spoils are dumped into valleys

Subsurface mining

Method to remove deep deposits of minerals

Tailings

Rock and other waste materials removed as impurities when waste mineral material is separated from the metal in an ore. Left in piles or ponds; can blow or wash into water sources.

Smelting

Process where heat or chemical solvents are used to extract metals from mineral ores. Releases large quantities of air pollutants (sulfur dioxide

Tectonic plates

Gigantic solid plates formed from the breaking up of the lithosphere (crust and rigid outer mantle)

Earthquake

Event that occurs when a fault forms or when there is abrupt movement on an existing fault

Tsunami

A series of large waves generated when part of the ocean floor suddenly rises or drops

Volcano

Occurs where magma rising in a plume through the lithosphere reaches the earth's surface through a central vent or a long crack called a fissure. Eruptions release lava rock

Old-growth (primary) forest

An uncut or regrown forest that has not been seriously disturbed by human activities or natural disasters for 200 years or more. Reservoirs of biodiversity.

Second-growth forest

A stand of trees resulting from secondary ecological succession after the trees in an area have been removed by human activities or natural forces.

Tree farm (commercial forest)

A managed forest that contains only one or two species of trees that are all the same age

Selective cutting

Method of harvesting trees where intermediate-aged and mature trees are cut singly or in small groups

Clear-cutting

Method of harvesting trees where all trees are removed from a geographic area. Most efficient and least costly

Strip cutting

Method of harvesting trees where trees are removed in sections parallel to a feature

Surface fire

A forest fire that usually burns only undergrowth and leaf litter on the forest floor

Crown fire

An extremely hot forest fire that leaps from treetop to treetop

Deforestation

The temporary or permanent removal of large expanses of forest for agriculture

Rangelands

Unfenced grasslands in temperate and tropical climates that supply forage for grazing (grass-eating) and browsing (shrub-eating) animals.

Pastures

Managed grasslands or fenced meadows often planted with domesticated grasses or other forage crops for livestock.

Overgrazing

The process where too many animals graze for too long

Rotational grazing

A method to prevent overgrazing by confining small groups of cattle by portable fencing to one area for a few days and then moving them to a new location.

Wilderness

Areas essentially undisturbed by humans and protected by federal law from harmful human activities. Protected under the 1964 Wilderness Act.

Biodiversity hotspot

Areas rich in highly endangered species found nowhere else (endemic species) and threatened by human activities

Ecological restoration

The process of repairing damage to ecosystems caused by human activities

Reconciliation ecology

An approach that focuses on establishing and maintaining new habitats to conserve species diversity in places where people live

Marine protected areas (MPAs)

Areas of ocean partially protected from human activities

Marine reserves

Areas of ocean declared off-limits to commercial fishing

Ocean acidification

The process where absorbed CO2 from the atmosphere combines with ocean water to form carbonic acid (H2CO3)

Fishery

A concentration of a particular aquatic species suitable for commercial harvesting in a given ocean area or inland body of water. 75% of world's fisheries are fully exploited or overfished.

Water footprint

A rough measure of the total volume of freshwater used directly or indirectly by a person

Hydrologic cycle (water cycle)

The continuous circulation of water through the biosphere

Zone of saturation

Underground area of soil/rock where freshwater fills spaces between particles. The top of this zone is the water table.

Confined (deep) aquifer

An aquifer that is sandwiched between layers of impermeable rock or clay. Cannot be recharged or takes thousands of years; nonrenewable on human timescale.

Unconfined aquifer

An aquifer that is recharged by precipitation that sinks downward through exposed soil and rock above it. Renewable if not overpumped.

Saltwater intrusion

The movement of saltwater into freshwater aquifers in coastal areas caused by overpumping of groundwater. Makes groundwater undrinkable and unusable for irrigation.

Reliable surface runoff

Surface runoff of water that generally can be counted on as a stable source of water from year to year. Approximately one-third of annual surface runoff.

Ogallala Aquifer

One of the world's largest aquifers

Contour planting

Soil conservation method where plowing and planting are done in rows across the slope of the land rather than up and down. Each row acts as a small dam to slow runoff.

Terracing

Soil conservation method where steeply sloped land is converted into a series of broad

Windbreaks (shelterbelts)

Rows of trees planted around crop fields to reduce wind erosion

Conservation-tillage farming

A variety of cultivation methods that leave a previous year's crop residues on fields before and during a new season's planting to reduce soil erosion. Includes no-till farming.

No-till farming

The purest form of conservation tillage where seeds are inserted through crop residue cover into unplowed soil. Minimizes soil disturbance and erosion.

Organic fertilizer

Fertilizer derived from plant and animal materials. Types include animal manure

Green manure

Freshly cut or growing green vegetation that is plowed into the topsoil to increase organic matter and humus available to the next crop.

Compost

A soil-like material produced when microorganisms break down organic matter such as leaves

Crop rotation

Planting a series of different crops in the same area from season to season. Helps reduce nutrient depletion (e.g.

Biomagnification

The increase in concentration of a chemical (such as DDT or mercury) in the tissues of organisms at successively higher trophic levels in a food chain or web.