Environmental Bio 3

key terms

species

a group of plants or animals that have a high degree of similarity and can generally only interbreed among themselves

biosphere

the sum total of all of Earth’s ecosystems

biomes

one of many distinctive types of ecosystems determined by climate and identified by the predominant vegetation and organisms that have adapted to live there

ecosystem

all of the organisms in a given area plus the physical environment in which and with which they interact

biotic

the living (organic) components of an ecosystem, such as the plants and animals and their waste (dead leaves, feces)

abiotic

the nonliving components of an ecosystem, such as rainfall and mineral composition of the soil

population

all the individuals of a species that live in the same geographic area and are able to interact and interbreed

community

all the populations (plants, animals, and other species) living and interacting in an area

matter cycles

movement of life’s essential chemicals or nutrients through an ecosystem

energy flow

the one-way passage of energy through an ecosystem

sinks

abiotic or biotic components of the environment that serve as storage places for cycling nutrients

range of tolerance

the range, within upper and lower limits, of a limiting factor that allows a species to survive and reproduce

photosynthesis

the chemical reaction performed by producers that uses the energy of the Sun to convert carbon dioxide and water into sugar and oxygen

producer

an organism that converts solar energy to chemical energy via photosynthesis

consumer

an organism that obtains energy and nutrients by feeding on another organism

cellular respiration

the process in which all organisms break down sugar to release its energy, using oxygen and giving off CO2 as a waste product

carbon cycle

movement of carbon through biotic and abiotic parts of an ecosystem via photosynthesis and cellular respiration as well as in and out of other reservoirs such as oceans, soil, rock, and atmosphere

nitrogen cycle

a continuous series of natural processes by which nitrogen passes from the air to the soil to organisms and then returns back to the air or soil

nitrogen fixation

conversion of atmospheric nitrogen into a biologically usable form, carried out by bacteria found in soil or via lightning

nitrification

conversion of ammonia to nitrate (NO3−)

denitrification

conversion of nitrate to molecular nitrogen (N2)

phosphorus cycle

a series of natural processes by which the nutrient phosphorus moves from rock to soil or water to living organisms and back to soil

groundwater

water found underground trapped in soil or porous rock

surface waters

any body of water found above ground, such as oceans, rivers, and lakes

water cycle

the movement of water through various water compartments such as surface waters, atmosphere, soil, and living organisms

transpiration

the loss of water vapor from plants

evapotranspiration

the combination of evaporation and transpiration

water war

political conflicts over the allocation of water sources

aquifer

an underground, permeable region of soil or rock that is saturated with water

infiltration

the process of water soaking into the ground

water table

the uppermost water level of the saturated zone of an aquifer

saltwater intrusion

the inflow of ocean (salt) water into a freshwater aquifer that happens when an aquifer has lost some of its freshwater stores

domestic water

indoor and outdoor water used by households and small businesses

water scarcity

not having access to enough clean water

potable

water that is clean enough for consumption

Safe Drinking Water Act (SDWA)

federal law that protects public drinking water supplies in the United States

wastewater

used and contaminated water that is released after use by households, businesses, industry, or agriculture

wastewater treatment

the process of removing contaminants from wastewater to make it safe enough to release into the environment

dams

a structure that blocks the flow of water in a river or stream

reservoirs

an artificial lake formed when a river is impounded by a dam

managed aquifer recharge

pumping the water underground into depleted aquifers

desalination

the removal of salt and minerals from seawater to make it suitable for consumption

direct use

water used to meet personal needs of cooking, washing, toilet flushing, and so on

water footprint

the water consumed by a given group (that is, person or population) or appropriated and/or polluted by industry to produce products or energy

water pollution

the addition of any substance to a body of water that might degrade its quality

stormwater runoff

water from precipitation that flows over the surface of the land

thermal pollution

the heated water released into surface waters near power plants

point source pollution

pollution from wastewater treatment plants or industrial sites, such as that from discharge pipes or smokestacks

effluent

wastewater discharged into the environment

pathogens

disease-causing organisms

non-point source pollution

runoff that enters the water from overland flow.

sediment pollution

eroded soil that is washed into the water through runoff

dissolved oxygen (DO)

the amount of oxygen in the water

hypoxia

a situation in which a body of water contains inadequate levels of oxygen, compromising the health of many aquatic organisms

eutrophication

a process in which excess nutrients in aquatic ecosystems feed biological productivity, ultimately lowering the oxygen content in the water

watershed

the land area surrounding a body of water over which water such as rain can flow and potentially enter that body of water

tributaries

rivers or streams flowing into a larger river or lake

biological assessment

the process of sampling an area to see what lives there as a tool to determine how healthy the area is

benthic macroinvertebrates

easy-to-see (not microscopic) arthropods such as insects that live on the stream bottom

Clean Water Act (CWA)

U.S. federal legislation that regulates the release of point source pollution into surface waters and sets water quality standards for those waters. It also supports best management practices to reduce nonpoint source pollution

performance standards

the levels of pollutants allowed to be present in the environment or released over a certain time period

watershed management

management of what goes on in an area around streams and rivers

total maximum daily loads (TMDLs)

the maximum amount of a pollutant allowed to enter a waterbody so that the waterbody will meet water quality standards

riparian areas

the land areas close enough to a body of water to be affected by the water’s presence (e.g., areas where water-tolerant plants grow) and that affect the water itself (e.g., provide shade)

acidification

the lowering of the pH of a solution

marine calcifiers

organisms that make a hard calcium-based shell or exoskeleton

coral reefs

a large underwater structure formed by colonies of tiny animals (corals) that produce a calcium carbonate exoskeleton that over time builds up; commonly found in shallow, warm, tropical seas

estuaries

a region where a river empties into the ocean

corals

colonial marine animal that secretes a hard outer shell in which it lives and is mutualistically dependent on an algal partner.

zooxanthellae

mutualistic photosynthetic algal partner of a coral polyp; each provides nutrients that the other needs

coral bleaching

a stress response in a coral in which the mutualistic algal partner is expelled; this weakens and even can kill the coral if it is not recolonized soon

food security

having physical, social, and economic access to sufficient safe and nutritious food

food desert

a locale where access to affordable, fresh, and nutritious food is limited or nonexistent

malnutrition

a state of poor health that results from inappropriate caloric intake (too many or too few calories) or is deficient in one or more nutrients

Green Revolution

a plant-breeding program in the mid-1900s that dramatically increased crop yields and paved the way for mechanized, large-scale agriculture

industrial agriculture

farming methods that rely on technology, synthetic chemical inputs, and economies of scale to increase productivity and profits

monoculture

a farming method in which a single variety of one crop is planted, typically in rows over huge swaths of land, with large inputs of fertilizer, pesticides, and water

genetic diversity

the heritable variation among individuals of a single population or within a species as a whole

fertilizer

a natural or synthetic mixture that contains nutrients that is added to soil to boost plant growth

pesticides

a natural or synthetic chemical that kills or repels plant or animal pests

pesticide resistance

the ability of a pest to withstand exposure to a given pesticide; the result of natural selection favoring the survivors of an original population that was exposed to the pesticide

Genetically modified organisms (GMOs)

organism that has had its genetic information modified to give it desirable characteristics such as pest or drought resistance

transgenic organisms

an organism that contains genes from another species

intragenic organism

an organism whose own DNA has been edited

cisgenic organism

an organism that received DNA from a close relative, DNA that could have been acquired via traditional breeding

cash crops

food and fiber crops grown to sell for profit rather than for use by local families or communities

sustainable agriculture

farming methods that can be used indefinitely because they do not deplete resources, such as soil and water, faster than they are replaced

organic agriculture

farming that does not use synthetic fertilizer, pesticides, GMOs, or other chemical additives like hormones (for animal rearing)

soil

a complex ecosystem of mineral and organic material, including living organisms such as bacteria, invertebrates, and fungi, that supports the growth of plants and is, in turn, affected by those plants

soil erosion

the process in which soil is moved from one location to another, most often by wind and water

agroecology

a scientific field that considers the area’s ecology and indigenous knowledge and favors agricultural methods that protect the environment and meet the needs of local people

polyculture

a farming method in which a mix of different species are grown together in one area

food miles

the distance a food travels from its site of production to the consumer

integrated pest management (IPM)

the use of a variety of methods to control a pest population, with the goal of minimizing or eliminating the use of chemical toxins

concentrated animal feeding operations (CAFOs)

a situation in which meat or dairy animals are raised in confined spaces, maximizing the number of animals that can be reared in a small area

feed conversion ratio

the amount of edible food that is produced per unit of feed input

water footprint

the water consumed by a given group (that is, person or population) or appropriated and/or polluted by industry to produce products or energy

U.S. Farm Bill

legislation that deals with many aspects of the production and sale of farm-raised commodity crops

bycatch

nontarget species that become trapped in fishing nets and are usually discarded

collapsed fishery

a fishery in which annual catches fall below 10% of their historic high; stocks can no longer support a fishery