Unit One: The Living World - Ecosystems

nutrient cycling

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

nitrogen cycle

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

Water Cycle (Hydrologic Cycle)

The continuous movement of water on, above, and below the surface of the Earth.

phosphorus cycle

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

carbon cycle

the movement of carbon from the nonliving environment into living things and back

limiting factor

Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.

Decomposition

A chemical reaction that breaks down compounds into simpler products.

Detritivore

organism that feeds on plant and animal remains and other dead matter

Water Treatment

The process of purifying water to make it suitable for consumption and utilization

waste water treatment

the process of improving the quality of waste water (sewage) to the point that it can be released into a body of water without seriously disrupting the aquatic environment, causing health problems in humans, or causing nuisance conditions

food web

a system of interlocking and interdependent food chains.

water quality

used to describe the health of a water system

Temperature

A measure of how hot or cold something is.

pH

hydrogen ion concentration

Dissolved Oxygen (DO)

the amount of oxygen in the water

Nitrates

NO3-

Nitrites

NO2-

Ammonia

NH3

soil quality

soil profile

soil fertility

A measure of how well soil supports plant growth.

NPK

nitrogen, phosphorus, potassium

soil structure

the arrangement of soil particles

Leaching

removal of dissolved materials from soil by water moving downwards

tannins（tannin）

Tannins are fermented organic materials that are created by the breakdown of vegetation

drainage

Removal of groundwater or surface water, or of water from structures, by gravity or pumping.

Eutrophication

A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.

Biological Oxygen Demand (BOD)

The amount of oxygen needed by microorganisms to decompose biological wastes into carbon dioxide, water, and minerals.

pollutants（pollutant）

a substance that pollutes something, especially water or the atmosphere.

germinate

to begin to grow, come into being

Legumes

plants of the bean and pea family, with seeds that are rich in protein compared with other plant-derived foods

nitrogen fixation

Process of converting nitrogen gas into ammonia

silt

A mixture of rich soil and tiny rocks

Turbidity

A measure of how clear water is.

mitigate

to make less severe

Ecology

The study of how living things interact with each other and their environment

Species

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

Speciation

Formation of new species

Producer

An organism that can make its own food.

Photosynthesis

Conversion of light energy from the sun into chemical energy.

cellular respiration

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

Consumer

An organism that obtains energy by feeding on other organisms

Population

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

individual

a single organism

community

All the different populations that live together in an area

Ecosystem

A biological community of interacting organisms and their physical environment.

habitat

Place where an organism lives

Niche

An organism's particular role in an ecosystem, or how it makes its living.

Abiotic

Non-living

Biotic

living

scavenger

A carnivore that feeds on the bodies of dead organisms

energy pyramid

A diagram that shows the amount of energy that moves from one feeding level to another in a food web

2nd law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

Biomimicry

the design and production of materials, structures, and systems that are modeled on biological entities and processes.

Heterotroph

An organism that cannot make its own food.

Herbivore

A consumer that eats only plants.

ecological efficiency

the proportion of consumed energy that can be passed from one trophic level to another

Carnivore

A consumer that eats only animals.

Omnivore

An animal that eats both plants and animals

1st law of thermodynamics

Energy cannot be created or destroyed

Decomposer

An organism that breaks down wastes and dead organisms

10% Rule

Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.

competition

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

interspecific competition

competition between members of different species

intraspecific competition

competition between members of the same species

competitive exclusion

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

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

Predation

An interaction in which one organism kills another for food.

Symbiosis

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

Parasitism

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

Commensalism

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

Mutualism

A relationship between two species in which both species benefit

Amensalism

a relationship in which one organism is harmed and the other is unaffected

invasive species

plants and animals that have migrated to places where they are not native

Biomes

a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.

Latitude

Distance north or south of the equator

altitude

Elevation above sea level

Ecotone

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

edge effect

the condition in which, at ecosystem boundaries, there is greater species diversity and biological density than there is in the heart of ecological communities.

desert

An extremely dry area with little water and few plants

Grassland

A biome where grasses are the main plant life

Savannah

a flat grassland in tropical or subtropical regions

Chapparal

A scrubland biome of dense, spiny evergreen shrubs found at midlatitudes along coasts where cold ocean currents circulate offshore; characterized by mild, rainy winters and long, hot, dry summers.

Tundra

An extremely cold, dry biome.

tropical rainforest

a broadleaf evergreen forest found in wet and hot regions near the equator.

temperate rainforest

a coastal biome typified by moderate temperatures and high precipitation

temperate deciduous forest

forest in a temperate region, characterized by trees that drop their leaves annually

Taiga

Biome in which the winters are cold but summers are mild enough to allow the ground to thaw

Permafrost

Ground that is permanently frozen

Ecoregion

A relatively large area that is characterized by distinctive plant and animal communities, climate, and ecological features.

endemic

confined to a particular country or area

Lentic

still water

Lotic

flowing water

littoral zone

a shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants

limnetic zone

a zone of open water in lakes and ponds

profundal zone

a region of water where sunlight does not reach, below the limnetic zone in very deep lakes

benthic zone

the muddy bottom of a lake, pond, or ocean

Floodplain

The area subject to flooding during a given number of years according to historical trends.

marsh

a wetland typically covered with grasses

swamp

A wetland ecosystem in which shrubs and trees grow

Estuaries

A bay or drowned valley where a river empties into the sea