3RD LE Flashcards
evolution of two interacting species, each in response to selection pressure imposed by the other
coevolution
parasite that lives on the surface of another organism
ectoparasite
parasite that lives inside the body of its host organism
endoparasite
organism on or within which an herbivore, parasite, or mutualist lives and feeds
host
relatively large parasite species, such as arthropods and worms
macroparasite
parasite species too small to be seen with the naked eye, such as bacteria, protists, and fungi
microparasite
organism that lives in or on a host organism and feeds on its tissues or body fluids
parasite
insect that lays on or a few eggs on or in a host organism (itself usually an insect), which the resulting larvae remain with, eat, and almost always kill
parasitoid
parasite that causes disease
pathogen
organism that lives in or on an organism of another species, referred to as its host; a symbiont is the smaller member of a symbiosis
symbiont
minimum number of individuals susceptible to a disease that must be present in a population for the disease to become established and spread
threshold density
In a mutualism, an individual that increases its production of offspring by overexploiting its mutualistic partner
cheater
species interaction in which individuals of one species benefit while individuals of the other species do not benefit and are not harmed (+/0 relationship).
commensalism
mutualism in which one partner provides the other with shelter, a place to live, or favorable habitat
habitat mutualism
mutually beneficial interaction between individuals of two or more species (+/+ relationship)
mutualism
trophic or non-trophic species interaction in which one or both species benefit and neither is harmed
positive interaction
relationship in which two species live in close physical and/or physiological contact with each other
symbiosis
mutualism in which one or both of the mutualists receives energy or nutrients from its partner
trophic mutualism
diversity of important ecological entities that span multiple spatial scales, from genes to species to communities
biodiversity
group of interacting species that occur together at the same place and time
community
set of characteristics that shape a community, including the number, composition, and abundance of species
community structure
interaction that occurs between two species, such as predation, competition, or a positive interaction
direct interaction
species that influences its community by creating, modifying, or maintaining physical habitat for itself and other species
ecosystem engineer
diagram showing the connections between organisms and the food they consume
food web
species that has large, community-wide effects on the habitat or food of other species by virtue of its size or abundance
foundation species
subset of a community that includes species that function in similar ways, but do not necessarily use the same resources
functional group
subset of a community that includes species that use the same resources, whether or not they are taxonomically related
guild
non-trophic interactions, such as competition and some positive interactions, that occur within a trophic level
horizontal interactions
interaction in which the relationship between two species is mediated by a third (or more) species
indirect interaction
measure of the effect on one species (the interactor) on the abundance of another species (the target species)
interaction strength
concept that describes both the trophic (vertical) and non-trophic (horizontal) interactions among the species in a traditional food web
interaction web
strong interactor species that has an effect on energy flow and community structure that is disproportionate to its small size, abundance, or biomass
keystone species
graph that plots the proportional abundance of each species in a community relative to the others in rank order, from most abundant to least abundant
rank abundance curve
having the same function in a community as other species in that community within a larger functional group
redundant species
index most commonly used to describe species diversity quantitatively
shannon index
graph that plots species richness as a function of the total number of individuals that are present with each additional sample
species accumulation curve
identity of the species present in a community
species composition
measure that combines the number of species (species richness) in a community and their relative abundances compared with one another (species evenness)
species diversity
relative abundances of different species compared to one another in a community
species evenness
number of species in a community
species richness
change in the rate of consumption at one trophic level that results in a series of changes in species abundance or composition at lower trophic levels
trophic cascade
interaction in which a consumer is directly facilitated by a positive interaction between its prey or food plant and another species
trophic facilitation
group of species that obtain energy in similar ways, classified by the number of feeding steps by which the group is removed from primary producers, which are the first trophic level
trophic level
different community development scenarios, or community states, that are possible at the same location under similar environmental conditions
alternative stable states
last stage of succession that is thought to be stable until disturbances or stresses shift the community back to earlier successional stages
climax stage
abiotic event that kills or damages some individuals and thereby creates opportunities for other individuals to grow and reproduce
disturbance
inability of a community that has undergone change to shift back to the original community type, even when the original conditions are restored
hysteresis
first stage of primary succession
pioneer stage
succession that involves the colonization of habitats devoid of life
primary succession
succession that involves the reestablishment of a community in which some, but not all, of the organisms have been destroyed
secondary succession
when a community retains, or returns to, its original structure and function after some perturbation
stability
process of change in the species composition of a community over time as a result of abiotic and biotic agents of change
succession
