Biological Interactions Flashcards
Ecology
The study of relationships between organisms and their environments.
Environment
The condition (biotic and abiotic) in which an organism lives.
Biosphere
The part of Earth the supports life.
Habitat
A specific location, with a particular set of abiotic and biotic conditions; where an organism normally lives.
Population
Number of individuals of a species living in a particular place at a particular time.
Community
All species that occupy a particular place at a given time.
Ecosystem
A biological community of interacting organisms and their physical environment.
Niche
A species’s role and position in its environment; a species’s interactions with the biotic and abiotic factors of its environment.
Abiotic
The non-living physical factors that affect an organism’s ability to survive.
Producer
(Autotrophic) organism forming the base of all food chains; converts simple inorganic chemicals into complex organic molecules (food).
Consumer
Organism that eats other living organisms (or part of an organism) for nutrition.
Heterotroph
An organism that eats other living organisms.
Herbivore
Plant-eating organism.
Carnivore
Meat-eating organism.
Omnivore
An organism that can utilise a range of nutrients; both herbivores and carnivores.
Detritivore
An organism that feeds on detritus.
Decomposer
An organism (eg. bacteria and fungi) that utilises dead organisms or waste matter for its nutrients, releasing simple inorganic molecules.
Optimal Range
The level of an abiotic factor at which an organism will best survive.
Physiological Stress
The inability of an organism to function at maximum efficiency as a result of some factor.
Tolerance Range
The range of a particular abiotic factor within which organisms can survive.
Cryptic Organism
An organism that has the ability to avoid observation or detection by using camouflage, nocturnally, underground habitat, mimicry or any other method of concealment.
Intraspecific
Within a species; between individuals of the same species.
Interspecific
Between different species.
Predator
An organism that captures, kills and feeds on another animal.
Competition
Rivalry between individuals, of the same or different species, for a specific resource.
Symbiosis
A relationship in which two organisms live in close association over a long period of time.
Mutualism
Necessary and positive association between two organisms.
Cooperation
Association between (or within) species that benefits both but is not essential for survival of either.
Commensalism
Relationship between two organisms in which one organism benefits and the other organism is not affected.
Amensalation
A relationship in which one species is inhibited by another.
Parasitism
Association between organisms in which one species (the parasite) is completely dependant upon the other (the host), which is usually harmed.
Distribution
Regions in which a species is found.
Abundance
Number (of a species) in a specific area at any time.
Holdridge Life Zone System
A system of classifying areas of land, encompassing climate and ecological types.
Plankton-Nekton Ecosystem
The ecosystem of the ocean surface consisting of nekton (free swimmers) and plankton (microscopic organisms).
Nekton
Free-swimming organisms of surface waters.
Benthic Ecosystem
The ecosystem at the lowest level of a body of water; includes the sediment surface and some subsurface layers.
Littoral Zone
The zone between water and land, which may be affected by tidal action.
Netric Zone
Shallow region of the ocean overlying the continental shelves.
Abyssal Zone
Deep-water-zone (depth 4000-6000)
Biome
The living organisms of a large area defined by its climate and dominant plant species (eg. a desert community).
Vertical Stratification
The vertical arrangement of vegetation into layers (or strata), providing a variety of niches.
Canopy
The upper layer or habitat zone, formed by mature tree crowns.
MIcrohabitat
A small habitat that may be different from the surrounding larger habitat.
Ecozone
A large area in which organisms have been evolving in relative isolation over long periods of time.
Ecoregion
A subdivision of an ecozone; a geographically distinct community based on geology, soils, climate and predominant vegetation.
Monoculture
A system that has very low diversity; in agriculture, it describes the practice of growing a single crop type.
Species Richness
A measure of the number of species present and the evenness of species in relation to one another.
Species Diversity
A measure of the number of species found in a community, compared with the number of individuals.
Simpson’s Index (D)
The probability that two individuals randomly selected from a sample will belong to the same species (or genus or family etc).
Simpson’s Diversity Index (SDI)
The probability that two individuals randomly selected from a sample will belong to different species (or groups).
Zonation
The breaking of the biome into a habitat zones.
Stratification
The division of the physical environment into smaller components for sampling.
Random Sampling
A method of selecting a sample from a total array in such a way that every possible sample could be selected has an equal chance of being selected.
Foliage Cover
An estimate of the area or percentage of a sample site occupied by the natural spread of plant foliage.
Plot
An area under investigation- generally a subset of a larger area.
Quadrat
A rectangular or square plot of known dimensions.
Quadrant
Each of four quarters of a circle.
Transect
A measured length or strip of terrain in an environment along which individual organisms or environmental parameters are measured and recorded.
Belt Transect
An elongated area of known length and with through a particular environment in which specific community parameters are measured and recorded.
Profile
A slope of the terrain, position and height of vegetation type, and canopy cover.
Plan Sketch
An aerial view showing position and canopy cover of a species.
Line Intercepts
A sampling technique used to estimate relative densities of a species by counting the number of individuals that lie on a straight line cutting through the community.
Strip Census
An estimate of the numbers of a wild animals in an area by counting individuals along a typical strip and assuming a uniform position.
Berlese-Tullgren Funnel
A device used to extract small animals from leaf litter.
Pit-Fall Trap
A device used to trap small animals that are active on the ground surface.
Capture-Recapture
A method of estimating population density of animals where animals are captured, marked and released; their proportion in subsequent trapping allows estimation of population size.
Lincoln Index (N)
A method used to estimate the size of closed populations in which random samples of the population are captured, marked and released to mingle with the general population for a period of time before subsequent trapping.
