APES Midterm

Primary productivity

Rate at which organic matter is created by producers in an ecosystem.

Phytoplankton

Microscopic, free-floating, autotrophic organisms that function as producers in aquatic ecosystems.

GPP (gross primary productivity)

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

NPP

Net Primary Productivity: the energy captured by producers in an ecosystem minus the energy producers respire.

Trophic levels

The hierarchical levels of the food chain through which energy flows from primary producers to primary consumers, secondary consumers and so on.

Conservation of matter

The principle stating that matter is not created or destroyed during a chemical reaction.

Omnivore

A consumer that eats both plants and animals.

Carnivore

A consumer that eats only animals.

Herbivore

A consumer that eats only plants.

First law of thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed.

Second law of thermodynamics

When energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat).

Energy pyramid

Shows the amount of energy that moves from one feeding level to another in a food web.

10% rule

Only 10% of the total energy produced at each trophic level is available to the next level.

Food chain

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

Food web

A system of interlocking and interdependent food chains.

Producers (autotrophs)

Organisms that make their own food.

Ecological pyramids

Illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web.

Primary consumers

Animals that feed on producers; ex. herbivores.

Secondary consumers

Carnivores that eat herbivores.

Tertiary consumers

Carnivores that eat secondary consumers.

Heterotrophs

An organism that obtains organic food molecules by eating other organisms or their by-products.

Reservoir

A large store of (water, carbon).

Organic

Of, relating to, or derived from living matter; contains carbon.

Inorganic

Not formed from living things or the remains of living things.

Carbon cycle

The organic circulation of carbon from the atmosphere into organisms and back again.

Carbon sinks

Places such as forests, ocean sediments, and soil, where accumulated carbon does not readily reenter the carbon cycle.

Photosynthesis

Plants use the sun's energy to convert water and carbon dioxide into sugars and oxygen.

Cyanobacteria

Bacteria that can carry out photosynthesis.

Cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen, releases CO2.

Decomposition

A chemical reaction that breaks down compounds into simpler products.

Decomposer

An organism that breaks down wastes and dead organisms.

Leaf litter

Decomposing but recognizable leaves and other debris forming a layer on top of the soil, especially in forests.

Detritivore

Organism that feeds on plant and animal remains and other dead matter.

Nitrogen

N 7.

Nitrogen cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere.

Nitrification

Conversion of ammonia (NH4+) into nitrite (NO2-) and then into nitrite (NO3-).

Nitrogen fixation

Process of converting nitrogen gas (N2) in the atmosphere into nitrogen compounds that plants can absorb and use.

Ammonification

Fungal and bacterial decomposers use nitrogen-containing wastes and dead bodies as a food source and excrete ammonium (NH4+).

Denitrification

Process by which bacteria convert nitrates (NO3-) into nitrogen gas (N2).

Impervious surfaces

Surfaces that don't absorb water; e.g. roads, sidewalks, houses/buildings.

Leaching

Removal of dissolved materials from soil by water moving downwards.

Assimilation

The process by which producers incorporate elements into their tissues.

Phosphorus

P 15.

Phosphorus cycle

The movement of phosphorus atoms from rocks through the biosphere and hydrosphere and back to rocks.

Phosphorus sinks

Rocks and minerals, long-lived vegetation, dissolved PO4 ions, absorbed PO4 into particles, single-celled organisms.

Hydrologic cycle

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

Hydrology

The study of water and its effects on and in the earth and in the atmosphere.

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans.

Groundwater

Water held underground in the soil or in pores and crevices in rock.

Condensation

The change of state from a gas to a liquid (forms clouds).

Precipitation

Any form of water that falls from clouds and reaches Earth's surface.

Runoff

Water that flows over the ground surface rather than soaking into the ground.

Evaporation

The change of a substance from a liquid to a gas.

Infiltration

The process by which water on the surface enters the soil.

Transpiration

Evaporation of water from the leaves of a plant.

Percolation

The downward movement of water through soil and rock due to gravity.

Sublimation

A change directly from the solid to the gaseous state without becoming liquid.

Symbiosis

A relationship in which two different organisms live in close association with each other.

Ecosystem

A biological community of interacting organisms and their physical environment.

Mutualism

A relationship between two species in which both species benefit.

Parasitism

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

Interspecific competition

Competition between members of different species.

Competition

A common demand by two or more organisms upon a limited supply of a resource, for example, food, water, light, space, mates, nesting sites.

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.

Limiting factors

Conditions in the environment that put limits on where an organism can live.

Ecological niches

The role an organism plays in its environment.

Fundamental niche

The niche species could potentially occupy.

Realized niche

The niche species actually occupies.

Coevolution

Process by which two species evolve in response to changes in each other.

Competitive exclusion

Strong competition can lead to local elimination of one of the species.

Population

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

Community

All the different populations that live together in an area.

Biome

A group of ecosystems that share similar climates and typical organisms.

Terrestrial

Relating to the land.

Weather

The condition of Earth's atmosphere at a particular time and place.

Climate

The average weather conditions in an area over a long period of time.

Taiga

Biome with long cold winters and a few months of warm weather; dominated by coniferous evergreens.

Tundra

A vast, flat, treeless Arctic region where the subsoil is permanently frozen.

Temperate

Mild, moderate.

Temperate rainforest

The cool, dense, rainy forests of the northern Pacific coast.

Tropical

Warm, moist climate zone near the equator.

Tropic of Capricorn

A line of latitude about 23 degrees South of the equator.

Tropical rainforests

Biomes near the equator with warm weather and high precipitation.

Shrubland (chaparral)

Found along the California coast; characterized by hot summers and mild, rainy winters.

Temperate grasslands

Dominated by grasses with hot summers and cold winters, less rain than savannas.

Savanna

A grassy plain in tropical and subtropical regions, with few trees.

Desert

An extremely dry area with little water and few plants.

Latitude

Distance north or south of the Equator, measured in degrees.

Altitude

Elevation above sea level.

Longitude

Distance east or west of the prime meridian, measured in degrees.

Permafrost

Permanently frozen layer of soil beneath the surface.

Climatograms

Charts used to better understand climate by looking at average temperature and precipitation.

Biosphere

Part of Earth in which life exists including land, water, and air.

Aquatic

Relating to water.

Biotic

Describes living factors in the environment.

Abiotic

Describes non-living factors in the environment.

Streams

A small, narrow river.

Rivers

A large natural stream of water flowing in a channel.

Ponds

Bodies of fresh water that allow sunlight to go all the way through.

Lakes

A body of water surrounded by land.