Ecology Vocab

aerobic respiration
Complex process that occurs in the cells of most living organisms, in which nutrient organic molecules such as glucose (C6H12O6) combine with oxygen (O2) and produce carbon dioxide (CO2), water (H2O), and energy.
anaerobic respiration
Form of cellular respiration in which some decomposers get the energy they need through the breakdown of glucose (or other nutrients) in the absence of oxygen
autotroph
Organism that uses solar energy (green plant) or chemical energy (some bacteria) to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment
biodiversity
Variety of different species (species diversity), genetic variability among individuals within each species (genetic diversity), variety of ecosystems (ecological diversity), and functions such as energy flow and matter cycling needed for the survival of species and biological communities (functional diversity).
biomass
Organic matter produced by plants and other photosynthetic producers; total dry weight of all living organisms that can be supported at each trophic level in a food chain or web; dry weight of all organic matter in plants and animals in an ecosystem; plant materials and animal wastes used as fuel.
biotic
Living organisms.
carnivore
Animal that feeds on other animals.
chemosynthesis
Process in which certain organisms (mostly specialized bacteria) extract inorganic compounds from their environment and convert them into organic nutrient compounds without the presence of sunlight.
community
Populations of all species living and interacting in an area at a particular time.
decomposer
Organism that digests parts of dead organisms and cast-off fragments and wastes of living organisms by breaking down the complex organic molecules in those materials into simpler inorganic compounds and then absorbing the soluble nutrients. Producers return most of these chemicals to the soil and water for reuse. Decomposers consist of various bacteria and fungi.
detritivore
Consumer organism that feeds on detritus, parts of dead organisms, and cast-off fragments and wastes of living organisms. The two principal types are detritus feeders and decomposers.
detritus
Parts of dead organisms and cast-off fragments and wastes of living organisms.
detritus feeder
Organism that extracts nutrients from fragments of dead organisms and their cast-off parts and organic wastes. Examples are earthworms, termites, and crabs.
dissolved oxygen (DO) content
Amount of oxygen gas (O2) dissolved in a given volume of water at a particular temperature and pressure, often expressed as a concentration in parts of oxygen per million parts of water.
distribution
Area over which we can find a species.
ecological diversity
The variety of forests, deserts, grasslands, oceans, streams, lakes, and other biological communities interacting with one another and with their nonliving environment.
ecological efficiency
Percentage of energy transferred from one trophic level to another in a food chain or web.
ecology
Study of the interactions of living organisms with one another and with their nonliving environment of matter and energy; study of the structure and functions of nature.
ecosystem
Community of different species interacting with one another and with the chemical and physical factors making up its nonliving environment.
fermentation
Form of cellular respiration in which some decomposers get the energy they need through the breakdown of glucose (or other nutrients) in the absence of oxygen.
food chain
Series of organisms in which each eats or decomposes the preceding one.
food web
Complex network of many interconnected food chains and feeding relationships.
functional diversity
Biological and chemical processes or functions such as energy flow and matter cycling needed for the survival of species and biological communities.
genetic diversity
Variability in the genetic makeup among individuals within a single species.
gross primary productivity (GPP)
The rate at which an ecosystem’s producers capture and store a given amount of chemical energy as biomass in a given length of time.
habitat
Place or type of place where an organism or population of organisms lives.
herbivore
Plant-eating organism. Examples are deer, sheep, grasshoppers, and zooplankton.
HIPPO
Acronym for habitat destruction and fragmentation, invasive species, population growth, pollution, and overharvesting.
hydrologic cycle
Biogeochemical cycle that collects, purifies, and distributes the earth’s fixed supply of water from the environment to living organisms and then back to the environment.
kilocalorie (kcal)
Unit of energy equal to 1,000 calories.
limiting factor
Single factor that limits the growth, abundance, or distribution of the population of a species in an ecosystem.
limiting factor principle
Too much or too little of any abiotic factor can limit or prevent growth of a population of a species in an ecosystem, even if all other factors are at or near the optimum range of tolerance for the species.
net primary productivity (NPP)
Rate at which all the plants in an ecosystem produce net useful chemical energy; equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (gross primary productivity) and the rate at which they use some of that energy through cellular respiration.
nitrogen cycle
Cyclic movement of nitrogen in different chemical forms from the environment to organisms and then back to the environment.
nitrogen fixation
Conversion of atmospheric nitrogen gas into forms useful to plants by lightning, bacteria, and cyanobacteria; it is part of the nitrogen cycle.
nutrient
Any food or element an organism must take in to live, grow, or reproduce.
nutrient cycle
Natural processes that recycle nutrients in various chemical forms from the nonliving environment to living organisms and then back to the nonliving environment. Examples are the carbon, oxygen, nitrogen, phosphorus, sulfur, and hydrologic cycles.
omnivore
Animal that can use both plants and other animals as food sources. Examples are pigs, rats, cockroaches, and people.
phosphorus cycle
Cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment.
photosynthesis
Complex process that takes place in cells of green plants. Radiant energy from the sun is used to combine carbon dioxide (CO2) and water (H2O) to produce oxygen (O2) and carbohydrates (such as glucose, C6H12O6) and other nutrient molecules.
population
Group of individual organisms of the same species living in a particular area.
primary consumer
Organism that feeds on all or part of plants (herbivore) or on other producers.
primary productivity
The rate at which an ecosystem’s producers capture and store a given amount of chemical energy as biomass in a given length of time.
producer
Organism that uses solar energy (green plant) or chemical energy (some bacteria) to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment.
pyramid of energy flow
Diagram representing the flow of energy through each trophic level in a food chain or food web. With each energy transfer, only a small part (typically 10%) of the usable energy entering one trophic level is transferred to the organisms at the next trophic level.
range
Area over which we can find a species.
range of tolerance
Range of chemical and physical conditions that must be maintained for populations of a particular species to stay alive and grow, develop, and function normally.
scavenger
Organism that feeds on dead organisms that were killed by other organisms or died naturally. Examples are vultures, flies, and crows.
secondary consumer
Organism that feeds only on primary consumers.
species
Group of organisms that resemble one another in appearance, behavior, chemical makeup and processes, and genetic structure. Organisms that reproduce sexually are classified as members of the same species only if they can actually or potentially interbreed with one another and produce fertile offspring.
species diversity
Number of different species and their relative abundances in a given area.
sulfur cycle
Cyclic movement of sulfur in different chemical forms from the environment to organisms and then back to the environment.
tertiary (higher level) consumers
Animals that feed on animal-eating animals. They feed at high trophic levels in food chains and webs. Examples are hawks, lions, bass, and sharks.
transpiration
Process in which water is absorbed by the root systems of plants, moves up through the plants, passes through pores (stomata) in their leaves or other parts, and evaporates into the atmosphere as water vapor.
trophic level
All organisms that are the same number of energy transfers away from the original source of energy (for example, sunlight) that enters an ecosystem. For example, all producers belong to the first trophic level, and all herbivores belong to the second trophic level in a food chain or a food web.
water cycle
Biogeochemical cycle that collects, purifies, and distributes the earth’s fixed supply of water from the environment to living organisms and then back to the environment.