Autotroph
organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer
Biodiversity
the total of the variety of organisms in the biosphere; also called biological diversity
Biomass
total amount of living tissue within a given trophic level
Carnivore
organism that obtains energy by eating animals
Consumer
organism that relies on other organisms for its energy and food supply; also called a heterotroph
Decomposer
organism that breaks down and obtains energy from dead organic matter
Detritivores
organism that feeds on plant and animal remains and other dead matter
Energy Transfer
The conversion of one form of energy into another, or the movement of energy from one place to another
Environment
the surroundings or conditions in which a person, animal, or plant lives or operates
Food Chain
a series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
Food web
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
Herbivore
organism that obtains energy by eating only plants
Heterotroph
organism that obtains food by consuming other living things; also called a consumer
Invasive Species
non-native (or alien) to the ecosystem under consideration
Limiting Factors
factor that causes population growth to decrease
Nitrogen Fixation
process of converting nitrogen gas into nitrogen compounds that plants can absorb and use
Omnivore
organism that obtains energy by eating both plants and animals
Photosynthesis
process used by plants and other autotrophs to capture light energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches
Primary Producer
first producer of energy-rich compounds that are later used by other organism
Scavenger
animal that consumes the carcasses of other animals
Secondary Consumer
The ecological succession that occurs on a preexisting soil after the primary succession has been disrupted or destroyed due to a disturbance that reduced the population of the initial inhabitants
Primary Succession
succession that occurs in an area in which no trace of a previous community is present
Trophic level
each step in a food chain or food web
Carrying capacity
largest number of individuals of a particular species that a particular environment can support
Habitat
area where an organism lives including the biotic and abiotic factors that affect it
Niche
full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
Population growth
increase, over a specific period of time, in the number of individuals living in a country or region
Population density
number of individuals per unit area
Population
group of individuals of the same species that live in the same area
Competition
A symbiotic relationship between or among living things that compete for a limited resources, such as food, space, shelter, mate, ecological status, etc
Predation
interaction in which one organism (the predator) captures and feeds on another organism (the prey)
Benthic zone
a type of marine biome
Ecosystem
all the organisms that live in a place, together with their nonliving environment
Biotic
any living part of the environment with which an organism might interact
Abiotic
physical, or nonliving, factor that shapes an ecosystem
Biomagnification
increasing concentration of a substance, such as a toxic chemical, in the tissues of organisms at successively higher levels in a food chain
Community
assemblage of different populations that live together in a defined area
Species
a group of similar organisms that can breed and produce fertile offspring
Density-independent limiting factors
limiting factor that affects all populations in similar ways, regardless of the population density
Density-dependent limiting factors
limiting factor that depends on population density
Eutrophication
A choking of rivers, lakes and other waterways by excess algae growth which has been stimulated by fertilizers or sewage
Greenhouse effect
the process in which certain gases (carbon dioxide, methane, and water vapor) trap sunlight energy in Earth's atmosphere as heat
Ozone depletion
the wearing out (reduction) of the amount of ozone in the stratosphere
Secondary succession
type of succession that occurs in an area that was only partially destroyed by disturbances