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Pg. 188 -193 very important, especially part on 1998 Harmful Algal Bloom and Hypoxia Research and Control Act.

Convergent plate boundary

A region where plates are pushing together and where a mountain range, island arc, and/or trench will eventually form; often a site of much seismic and volcanic activity.


The solid, outer layer of the earth that consists of the crust and the rigid upper part of the mantle


In ecology a low concentration of dissolved oxygen in the bottom waters of a lake or ocean.


Liquid magma that reaches the surface; also the rock formed when liquid lava hardens.

positive feedback loop

Situation in which a change in a certain direction provides information that causes a system to change further in the same direction. For example erosion and population growth.

feedback loop

Occurs when an output of matter, energy, or information is fed back into the system as an input and leads to changes in that system.

negative feedback loop

Situation in which a change in a certain direction provides information that causes a system to change less in that direction.

Dynamic equilibrium

A state of balance in which opposing processes occur at the same rate


A tendency to maintain a balanced or constant internal state.

Emergent properties

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases.


The buildup over time of nutrients in freshwater lakes and ponds that leads to an increase in the growth of algae, usually due to an excess of nitrogen or phosphate.


The whole mass of air surrounding the earth


The watery areas of the earth, including oceans, lakes, rivers, and other bodies of water

Arthur Tansley

British ecologist who counted the term "ecosystem", particular portion of the world which forms a home for the organisms which inhabit it

Gross Primary Production

The total amount of energy fixed by all the autotrophs in an ecosystem

Net Primary Production

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

Secondary production

The amount of chemical energy in consumers' food that is converted to their own new biomass during a given time period

net primary productivity

The gross primary productivity minus the energy used by the producers for cellular respiration; represents the storage of chemical energy in an ecosystem available to consumers.


All the chemical substances that an organism needs to sustain life


The limiting nutrient of freshwater systems.


The limiting nutrient go marine systems.

Landscape Ecology

The application of ecological principles to the study of land-use patterns; the scientific study of the biodiversity of interacting ecosystems


An area of habitat that differs from its surroundings and has sufficient resources to allow a population to persist


The transition from one type of habitat or ecosystem to another, such as the transition from a forest to a grassland.


A collection of populations that have regular or intermittent gene flow between geographically separate units.


Geographic Information Systems, collection and display of data in an interactive and collaborative way to help organize for scientists to analyze and notice trends.

Nutrient cycle

The cyclic movement of a nutrient between organisms and the physical environment.

residence time

The average time a given particle will stay in a given system


The movement of nutrients between different reservoirs.


Pools(Reservoirs) that release more nutrients than they accept.


A pool(Reservoir) that accepts more nutrients than it releases

Carbon cycle

The process in an ecosystem in which producers take in carbon dioxide from the atmosphere during photosynthesis and consumers, having eaten producers, release carbon into the atmosphere as carbon dioxide

Phosphorous cycle

The movement of phosphorus from the nonliving environment into living things and then back into the nonliving environment

Nitrogen Cycle

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

Nitrogen fixation

The assimilation of atmospheric nitrogen by soil bacteria and its release for plant use on the death of the bacteria

nitrogen fixing bacteria

Bacteria that convert nitrogen in the air into forms that can be used by plants and animals.


The oxidation of ammonium compounds in dead organic material into nitrates and nitrites by soil bacteria (making nitrogen available to plants)

Haber-Bosch process

A process to synthesize ammonia on an industrial scale. The process has enabled humans to double the natural rate of nitrogen fixation on Earth and thereby increase agricultural productivity, but also altered the nitrogen cycle.

Fritz Haber

German Chemist. He won the 1918 Nobel Prize in chemistry for the development of the process used for synthesizing ammonia from its elements.

denitrifying bacteria

Bacteria which often live in damp soil, and which convert nitrates into nitrogen gas

Hydrological Cycle

The paths water take through its various states-vapor, liquid, solid- as it moves throughout the oceans, atmosphere, groundwater, streams, etc...


The process by which water changes from liquid form to an atmospheric gas


The emission of water vapor from the leaves of plants


Subterranean, porous, water-holding rocks that provide millions of wells with steady flows of water.

water table

The upper surface of underground water in an aquifer; the upper boundary of the zone of saturation

ground water

The part of the subsurface water that is in the zone of saturation, including underground streams.


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


The falling to earth of any form of water (rain or snow or hail or sleet or mist)


The process that converts sediments into solid rock by compaction or cementation.

sedimentary rock

A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together


A molten mixture of rock-forming substances, gases, and water from the mantle

igneous rock

A type of rock that forms from the cooling of molten rock at or below the surface.


A type of ingneous rock that generally contains large crystals and forms when magma cools slowly beneath Earth's surface. Best example is Granite


Fine-grained igneous rock that forms when magma cools quickly at or near Earth's surface. Best example is Basalt.

Metamorphic rock

A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reactions

Plate tectonics

The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle


The layer of hot, solid material between Earth's crust and core


The outer layer of the Earth


The central part of Earth below the mantle

Divergent plate boundaries

Situation with tectonic plates spreading apart, new crust being formed (ex. mid-ocean ridges, rift valleys).

transform plate boundary

Places where crustal plates shear laterally past one another. Crust is neither produced nor destroyed at this type of junction.

Moho discontinuity

Boundary between the crust and the mantle where seismic waves speed up


A geological process in which one edge of a crustal plate is forced sideways and downward into the mantle below another plate

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