AP Environmental Science Unit 1: The Living World: Ecosystems Vocabulary

competition

the struggle between organisms to survive in a habitat with limited resources

10% Rule (2nd Law of Thermodynamics)

When energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed on.

Abiotic

A nonliving condition or thing, as climate or habitat, that influences or affects an ecosystem and the organisms in it

Ammonia

A colorless gas with a characteristic pungent smell. It dissolves in water to give a strongly alkaline solution. (NH3)

Biogeochemical cycle

Process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another

Biome

A group of ecosystems that share similar climates and typical organisms

Biotic

Describes living factors in the environment.

Cellular Respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Community

CoA group of interdependent organisms inhabiting the same region and interacting with each other

Ecology

Scientific study of interactions among organisms and between organisms and their environment

Ecosystem

A biological community of interacting organisms and their physical environment.

food chain

A series of steps in which organisms transfer energy by eating and being eaten

food web

A community of organisms where there are several interrelated food chains

GPP (gross primary production)

The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time

Groundwater

water that fills the cracks and spaces in underground soil and rock layers

hydrologic cycle

The cycle through which water in the hydrosphere moves; includes such processes as evaporation, precipitation, and surface and groundwater runoff

Laws of Thermodynamics

The physical laws that define the basic properties and behavior of energy

Mutualism

A relationship between two species in which both species benefit

nitrogen fixation

process of changing nitrogen gas to nitrates that is carried out by nitrogen-fixing bacteria in the soil or in the roots of legumes

NPP (net primary production)

the gross primary production of an ecosystem minus the energy used by the producers for respiration.

nutrient

Compounds in food that the body requires for proper growth, maintenance, and functioning

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Photosynthesis

process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches

Population

A group of individuals that belong to the same species and live in the same area

primary productivity

the rate at which organic material is produced by photosynthetic organisms in an ecosystem

Producer

An organism that can make its own food.

reservoir

a large natural or artificial lake used as a source of water supply.

resource partitioning

The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species

sink

A reservoir that takes up a chemical element or compound from another part of its natural cycle

Source

Any process or activity through which a greenhouse gas is released into the atmosphere

Symbiosis

A close relationship between two species that benefits at least one of the species.

trophic level

each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.

uptake

The transfer of substances from the environment to plants, animals, and humans.

nitrogen fixation

process of converting nitrogen gas into nitrogen compounds that plants can absorb and use

Nitrification

the process by which nitrites and nitrates are produced by bacteria in the soil

Ammonification

The process by which fungal and bacterial decomposers break down the organic nitrogen found in dead bodies and waste products and convert it into inorganic ammonium

Denitrification

process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere

Carbon Cycle Steps

1. Carbon enters the atmosphere as carbon dioxide from respiration and combustion.
2. Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis.
3. Animals feed on the plant passing the carbon compounds along the food chain. Most of the carbon they consume is exhaled as carbon dioxide formed during respiration. The animals and plants eventually die.
4. The dead organisms are eaten by decomposers and the carbon in their bodies is returned to the atmosphere as carbon dioxide. In some conditions decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion.

nitrogen cycle steps

1. Nitrogen fixation
2. Nitrification
3. Assimilation
4. Ammonification
5. Denitrification

interspecific competition

competition between members of different species

intraspecific competition

competition between members of the same species

exploitation competition

Competing species have roughly equal access to a specific resource but differ in how fast or efficiently they exploit it. The species that can use the resource more quickly gets more of the resource and hampers the growth, reproduction, or survival of the other species

interference competition

when competitors do not immediately consume resources but defend them

Mutualism

A relationship between two species in which both species benefit

Omnivore

An animal that eats both plants and animals

scavenger

animal that consumes the carcasses of other animals that were killed by other predators

Detritivore

an animal that feeds on dead organic material, especially plant detritus.

Decomposer

an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material.

primary consumer

consumer that feeds directly on producers

secondary consumer

An organism that eats primary consumers

tertiary consumer

a carnivore at the topmost level in a food chain that feeds on other carnivores; an animal that feeds only on secondary consumers.

phosphorus cycle

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

cellular respiration

Process that releases energy (ATP) by breaking down glucose and other food molecules in the presence of oxygen

Transpiration

Evaporation of water from the leaves of a plant

Condensation

The change of state from a gas to a liquid, how clouds form

character displacement

Species evolve non-overlapping traits to avoid competition

competitive exclusion principle

Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time

Species

A group of similar organisms that can breed and produce fertile offspring.

Territoriality

the defense of a bounded physical space against encroachment by other animals, reduces competition

mimicry

Ability of an animal to look like another more harmful animal

trophic cascade

A series of changes in the population sizes of organisms at different trophic levels in a food chain, occurring when predators at high trophic levels indirectly promote populations of organisms at low trophic levels by keeping species at intermediate trophic levels in check. Trophic cascades may become apparent when a top predator is eliminated from a system.