Gaia Hypothesis

A theory in which the earth resembles a complex, living organism where the biotic and abiotic systems interact and are interdependent

Dynamic Equilibrium

The theoretical state of the earth in which change is continually occurring, but adjustments are being made to keep the system stable

Positive Feedback Loop

Enhances/magnifies the changes in a complex system

Negative Feedback Loop

Minimizes or brings to an equilibrium the changes in a complex system

Biosphere

All areas of the earth where life is found

Atmosphere

The envelope of gases surrounding earth, refers to the area above the ground

Lithosphere

The crust of the earth, the ground

Hydrosphere

The combined mass of water on earth, including precipitation and ice

Individual Organism

An individual plant, animal, or single-celled life form

Population

A group of a particular species of organisms living in a particular place at a specific time

Community

All of the populations that live in a specific area at a specific time

Ecosystem

Communities and their abiotic environments

Biodiversity

Describes the biological diversity, number, and variety of species that live in an ecosystem

Keystone Species

Species which can help to define an entire ecosystem due to its disproportionately large affect on its natural environment relative to its abundance

Indicator Species

Species of organisms that provide an early warning that an ecosystem’s biodiversity is compromised because it is very sensitive to changes of ecosystem conditions

Biomagnification

The concentration of toxins in an organism as a result of its ingesting other plants and animals in which the toxins are more widely dispersed

Trophic Level

A category of living things that is defined by how it gains its energy

Autotroph

An organism that creates its own energy

Heterotroph

An organism that obtains energy from other organisms

Food Chains

Describe trophic levels

Food Web

A representation of the feeding relationships amongst organisms in an ecosystem

1st Law of Thermodynamics

Energy cannot be created or destroyed, only transferred

2nd Law of Thermodynamics

During any energy transformation, some of the energy will be transformed into an unusable form (such as heat) and will therefore be lost to the system

10% Rule of Energy

Only around 10% of energy stored in a trophic level is available to be passed from one level to the next

Pyramid of Energy

A graphical representation of energy flow within an ecosystem; at each level the energy found within the bodies of organisms is graphed

Pyramid of Numbers

A tool used by scientists to represent the flow of energy in an ecosystem by using the number of organisms that exists at each level

Pyramid of Biomass

A tool used by scientists to represent the flow of energy in an ecosystem by using biomass of organisms that exist at each level

Organic Molecule

Any compound made by living things that contain carbon

Inorganic Molecule

Any compound that does not contain carbon

Cohesion

The phenomenon in which molecules stick to each other

Adhesion

The phenomenon in which molecules stick to other surfaces

Evapotranspiration

The general term for the process of water evaporating into the atmosphere

Condensation

The process in which water vapour is turned into liquid water

Precipitation

Water/snow falling to the earth

Surface Runoff

Unconfined water flowing over the surface of the ground

Percolation/Infiltration

The process of water moving downwards through the soil due to gravity

Leaching

The loss of water-soluble plant nutrients from the soil due to cohesion or adhesion

Water Table

Where pores/fracture of the ground are saturated with water

Recharge

Replenishment of an aquifer by absorption of water

Acid Deposition

Acid rain/snow from the burning of fossil fuel

Cyanobacteria

A single-celled photosynthesizing microbe that was first responsible for producing oxygen on Earth

Stromatolites

Layered mounds of sheet-like limestone rocks that were originally formed by the growth of cyanobacteria

Inorganic Carbon Compounds

Carbon compounds that are not made by living things

Inorganic Carbon Reservoirs

The atmosphere, the ocean, and the lithosphere

Organic Carbon Compound

A carbon compound derived from plants or animals that usually contains carbon and hydrogen

Organic Carbon Reservoirs

The bodies of living organisms; in peat, coal, crude oil, and natural gas stored in the ground

Human Enhanced Greenhouse Effect

The increase in concentrations of greenhouse gases due to the burning of fossil fuels, which is causing the atmosphere to absorb more heat and increase the rate of climate change

Nitrogen Fixation

The transformation of atmospheric nitrogen gas to a useable form of nitrogen by soil bacteria or legume roots

Assimilation

The incorporation of useable nitrogen into tissue

Ammonification

The transformation of organic nitrogen compounds to ammonia gas during decomposition

Nitrification

The transformation of ammonia into nitrites or nitrites into nitrate via nitrifying bacteria

Ammonia-nitrifying bacteria

Converts ammonia to nitrites

Nitrite-nitrifying bacteria

Converts nitrites to nitrates

Denitrification

The transformation of nitrites into nitrogen gas via denitrifying bacteria

Eutrophication

When the environment becomes enriched with nutrients from the accumulation of nitrates and phosphates, which results in prolific algae growth

Anoxic Water

Water that is low in oxygen