APES Unit 1 Test

Biodiversity

Variety of different species (species diversity), genetic variability among individuals within each species (genetic diversity), variety of ecosystems (ecological diversity), and functions such as energy flow and matter cycling needed for the survival of species and biological communities (functional diversity).

Common-Property resource

Resource that is owned jointly by a large group of individuals. One example is the roughly one–third of the land in the United States that is owned jointly by all U.S. citizens and held and managed for them by the government. Another example is an area of land that belongs to a whole village and that can be used by anyone for grazing cows or sheep. Compare open access renewable resource. See tragedy of the commons

Ecological Footprint

Amount of biologically productive land and water needed to supply a population with the renewable resources it uses and to absorb or dispose of the wastes from such resource use. It is a measure of the average environmental impact of populations in different countries and areas. See per capita ecological footprint

Ecosystem

One or more communities of different species interacting with one another and with the chemical and physical factors making up their nonliving environment.

Ecosystem Services

Natural services or natural capital that support life on the earth and are essential to the quality of human life and the functioning of the world’s economies. Examples are the chemical cycles, natural pest control, and natural purification of air and water. See natural resources.

Natural Resources

Materials such as air, water, and soil and energy in nature that are essential or useful to humans. See natural capital

Natural Services

Processes of nature, such as purification of air and water and pest control, which support life and human economies. See natural capital.

Non-Point Sources

Broad and diffuse areas, rather than points, from which pollutants enter bodies of surface water or air. Examples include runoff of chemicals and sediments from cropland, livestock feedlots, logged forests, urban streets, parking lots, lawns, and golf courses. Compare point source.

non-renewable resource

Resource that exists in a fixed amount (stock) in the earth’s crust and has the potential for renewal by geological, physical, and chemical processes taking place over hundreds of millions to billions of years. Examples include copper, aluminum, coal, and oil. We classify these resources as exhaustible because we are extracting and using them at a much faster rate than they are formed. Compare renewable resource.

Nutrient

Any chemical an organism must take in to live, grow, or reproduce.

Nutrient Cycling

The circulation of chemicals necessary for life, from the environment (mostly from soil and water) through organisms and back to the environment.

perpetual resource

Essentially inexhaustible resource on a human time scale because it is renewed continuously. Solar energy is an example. Compare nonrenewable resource, renewable resource.

point source

Single identifiable source that discharges pollutants into the environment. Examples include the smokestack of a power plant or an industrial plant, drainpipe of a meatpacking plant, chimney of a house, or exhaust pipe of an automobile. Compare nonpoint source.

renewable resource

Resource that can be replenished rapidly (hours to several decades) through natural processes as long as it is not used up faster than it is replaced. Examples include trees in forests, grasses in grasslands, wild animals, fresh surface water in lakes and streams, most groundwater, fresh air, and fertile soil. If such a resource is used faster than it is replenished, it can be depleted and converted into a nonrenewable resource. Compare nonrenewable resource and perpetual resource. See also environmental degradation

sustainability

Ability of earth’s various systems, including human cultural systems and economies, to survive and adapt to changing environmental conditions indefinitely.

sustainable living

Taking no more potentially renewable resources from the natural world than can be replenished naturally and not overloading the capacity of the environment to cleanse and renew itself by natural processes.

sustainable yield (sustained yield)

Highest rate at which a potentially renewable resource can be used indefinitely without reducing its available supply. See also environmental degradation.

tragedy of the commons

Depletion or degradation of a potentially renewable resource to which people have free and unmanaged access. An example is the depletion or more factors or processes so that the of commercially desirable fish species in the open ocean beyond areas controlled by coastal countries. See common–property resource, open access renewable resource.

first law of thermodynamics

Whenever energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed, but energy can be changed from one form to another; you cannot get more energy out of something than you put in; in terms of energy quantity, you cannot get something for nothing. See second law of thermodynamics.

law of conservation of energy

See first law of thermodynamics.

law of conservation of matter

In any physical or chemical change, matter is neither created nor destroyed but merely changed from one form to another; in physical and chemical changes, existing atoms are rearranged into different spatial patterns (physical changes) or different combinations (chemical changes).

negative feedback loop

Feedback loop that causes a system to change in the opposite direction from which is it moving. Compare positive feedback loop.

positive feedback loop

Feedback loop that causes a system to change further in the same direction. Compare negative feedback loop.

principles of sustainability

Principles by which nature has sustained itself for billions of years by relying on solar energy, biodiversity, and nutrient recycling

second law of thermodynamics

Whenever energy is converted from one form to another in a physical or chemical change, we end up with lower–quality or less usable energy than we started with. In any conversion of heat energy to useful work, some of the initial energy input is always degraded to lower–quality, more dispersed, less useful energy—usually low–temperature heat that flows into the environment; you cannot break even in terms of energy quality. See first law of thermodynamics.

aerobic respiration

Complex process that occurs in the cells of most living organisms, in which nutrient organic molecules such as glucose (C6H12O6) combine with oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy. Compare photosynthesis.

anaerobic respiration

Form of cellular respiration in which some decomposers get the energy they need through the breakdown of glucose (or other nutrients) in the absence of oxygen. Compare aerobic respiration.

biogeochemical cycle

Natural processes that recycle nutrients in various chemical forms from the nonliving environment to living organisms and then back to the nonliving environment. Examples include the carbon, oxygen, nitrogen, phosphorus, sulfur, and hydrologic cycles.

biomass

Organic matter produced by plants and other photosynthetic producers; total dry weight of all living organisms that can be supported at each trophic level in a food chain or web; dry weight of all organic matter in plants and animals in an ecosystem; plant materials and animal wastes used as fuel.

carbon cycle

Cyclic movement of carbon in different chemical forms from the environment to organisms and then back to the environment

decomposer

Organism that digests parts of dead organisms, and cast–off fragments and wastes of living organisms by breaking down the complex organic molecules in those materials into simpler inorganic compounds and then absorbing the soluble nutrients. Producers return most of these chemicals to the soil and water for reuse. Decomposers consist of various bacteria and fungi. Compare consumer, detritivore, producer.

detritivore

Consumer organism that feeds on detritus, parts of dead organisms, and castoff fragments and wastes of living organisms. Examples include earthworms, termites, and crabs. Compare decomposer.

ecosystem

One or more communities of different species interacting with one another and with the chemical and physical factors making up their nonliving environment.

food chain

Series of organisms in which each eats or decomposes the preceding one. Compare food web.

food web

Complex network of many interconnected food chains and feeding relationships. Compare food chain.

gross primary productivity (GPP)

Rate at which an ecosystem’s producers capture and store a given amount of chemical energy as biomass in a given length of time. Compare net primary productivity.

hydrologic cycle

Biogeochemical cycle that collects, purifies, and distributes the earth’s fixed supply of water from the environment to living organisms and then back to the environment.

hydrosphere

Earth’s liquid water (oceans, lakes, other bodies of surface water, and underground water), frozen water (polar ice caps, floating ice caps, and ice in soil, known as permafrost), and water vapor in the atmosphere. See also hydrologic cycle. Compare atmosphere, biosphere, geosphere.

sink

A natural reservoir that can receive energy or materials without undergoing change. For example, a carbon sink is a reservoir where carbon may be stored.

infiltration

Downward movement of water through soil.

net primary productivity (NPP)

Rate at which all the plants in an ecosystem produce net useful chemical energy; equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (gross primary productivity) and the rate at which they use some of that energy through cellular respiration. Compare gross primary productivity.

nitrogen cycle

Cyclic movement of nitrogen in different chemical forms from the environment to organisms and then back to the environment

nitrogen fixation

Conversion of atmospheric nitrogen gas, by lightning, bacteria, and cyanobacteria, into forms useful to plants; it is part of the nitrogen cycle.

phosphorus cycle

Cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment.

photosynthesis

Complex process that takes place in cells of green plants. Radiant energy from the sun is used to combine carbon dioxide (CO2) and water (H2O) to produce oxygen (O2), carbohydrates (such as glucose, C6H12O6), and other nutrient molecules. Compare aerobic respiration, chemosynthesis.

precipitation

Water in the form of rain, sleet, hail, and snow that falls from the atmosphere onto land and bodies of water.

primary consumer

Organism that feeds on some or all parts of plants (herbivore) or on other producers. Compare detritivore, omnivore, secondary consumer

producer

Organism that uses solar energy (green plants) or chemical energy (some bacteria) to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment. Compare consumer, decomposer.

pyramid of energy flow

Diagram representing the flow of energy through each trophic level in a food chain or food web. With each energy transfer, only a small part (typically 10%) of the usable energy entering one trophic level is transferred to the organisms at the next trophic level.

respiration

See aerobic respiration.

secondary consumer

Organism that feeds only on primary consumers. Compare detritivore, omnivore, primary consumer.

sulfur cycle

Cyclic movement of sulfur in various chemical forms from the environment to organisms and then back to the environment.

10% Rule

The 10% rule states that between one trophic level to the next only 10% of the energy is passed on to the next. So if producers have 10,000 J of energy stored through photosynthesis, then only 1000 J is passed on to primary consumers.

tertiary consumers

Animals that feed on animal–eating animals. They feed at high trophic levels in food chains and webs. Examples include hawks, lions, bass, and sharks. Compare detritivore, primary consumer, secondary consumer.

transpiration

Process in which water is absorbed by the root systems of plants, moves up through the plants, passes through pores (stomata) in their leaves or other parts, and evaporates into the atmosphere as water vapor

trophic level

All organisms that are the same number of energy transfers away from the original source of energy (for example, sunlight) that enters an ecosystem. For example, all producers belong to the first trophic level and all
herbivores belong to the second trophic level in a food chain or a food web.

commensalism

An interaction between organisms of different species in which one type of organism benefits and the other type is neither helped nor harmed to any great degree. Compare mutualism.

competition

Two or more individual organisms of a single species (intraspecific competition) or two or more individuals of different species (interspecific competition) attempting to use the same scarce resources in the same ecosystem.

host

Plant or animal on which a parasite feeds.

mutualism

Type of species interaction in which both participating species generally benefit. Compare commensalism.

parasitism

Interaction between species in which one organism, called the parasite, preys on another organism, called the host, by living on or in the host. See host, parasite.

predation

Interaction in which an organism of one species (the predator) captures and feeds on some or all parts of an organism of another species (the prey).

predator–prey relationship

Relationship that has evolved between two organisms, in which one organism has become the prey for the other, the latter called the predator. See predator, prey.

resource partitioning

Process of dividing up resources in an ecosystem so that species with similar needs (overlapping ecological niches) use the same scarce resources at different times, in different ways, or in different places. See ecological niche