handout 5 Flashcards
A parasite that feeds on the external surface of a host.
ecotparasite
The relative number of individuals of each age in a population.
age structure
The bright warning coloration of many animals with effective physical
or chemical defences
aposematic colouration
A type of mimicry in which a harmless species looks like a species that is
poisonous or otherwise harmful to predators
Batesian mimicry
Community organization in which mineral nutrients influence
community organization by controlling plant or phytoplankton
numbers, which in turn control herbivore numbers, which in turn
control predator numbers.
bottom-up model
he maximum population size that can be supported by the available
resources, symbolized as K.
carrying capacity
The tendency for characteristics to be more divergent in sympatric
populations of two species than in allopatric populations of the same
two species.
character displacement
The concept that when populations of two similar species contest for
the same limited resources, one population will use the resources more
efficiently and have a reproductive advantage that will eventually lead
to the elimination of the other population.
competitive exclusion
Camouflage that makes a potential prey difficult to spot against its
background.
cryptic colouration
In a stable population, a shift from high birth and death rates to low
birth and death rates
demographic transition
The number of individuals per unit area or volume
density
Referring to any characteristic that varies with population density.
density dependent
Referring to any characteristic that is not affected by population
density
density independent
Pattern of spacing among individuals within the boundaries of a
population.
dispersion
The concept that long food chains are less stable than short chains.
dynamic stability
hypothesis
The aggregate land and water area required by a person, city, or nation
to produce all of the resources it consumes and to absorb all of the
wastes it generates.
ecological footprint
The sum of a species’ use of the biotic and abiotic resources in its
environment
ecological niche
An organism that influences community structure by causing physical
changes in the environment.
ecosystem engineer
A parasite that lives within a host
endoparasite
The concept that the length of a food chain is limited by the inefficiency
of energy transfer along the chain
energetic hypothesis
The total evaporation of water from an ecosystem, including water
transpired by plants and evaporated from a landscape, usually
measured in millimetres and estimated for a year
evapotranspiration
Growth of a population in an ideal, unlimited environment, represented
by a J-shaped curve when population size is plotted over time
exponential population growth
The pathway along which food energy is transferred from trophic level
to trophic level, beginning with producers.
food chain
The interconnected feeding relationships in an ecosystem.
food web
The concept that moderate levels of disturbance can foster greater
species diversity than low or high levels of disturbance.
intermediate disturbance hypothesis
A relationship between individuals of two or more species in a
community
interspecific interaction
A species, often introduced by humans, that takes hold outside its
native range
invasive species
Reproduction in which adults produce offspring over many years; also
known as repeated reproduction
iteroparity
Selection for life history traits that are sensitive to population density;
also called density-dependent selection
k-selection
A species that is not necessarily abundant in a community yet exerts
strong control on community structure by the nature of its ecological
role or niche.
keystone species
An age-specific summary of the survival pattern of a population
life table
Population growth that levels off as population size approaches carrying
capacity.
logistic population growth
A group of spatially separated populations of one species that interact
through immigration and emigration
metapopulation
Reciprocal mimicry by two unpalatable species
mullerian mimicry
Maintains that communities change constantly after being buffeted by
disturbances
non-equilibrium
Occurs in an area where there were originally no organisms present and
where soil has not yet formed.
primary succession
Selection for life history traits that maximize reproductive success in
uncrowded environments; also called density-independent selection.
r-selection
The proportional abundance of different species in a community.
relative abundance
An age-specific summary of the reproductive rates in a population
reproductive table
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 co-existing species.
resource partitioning
A type of succession that occurs where an existing community has been
cleared by some disturbance that leaves the soil or substrate intact
secondart succession