Interactions Flashcards
involves direct interaction between individuals
Interference Competition
is a condition where there is a limited supply of
resource
Resource limitation
takes place when
members of the same species compete
Intraspecific competition
happens between
individuals of two species that reduces the
fitness of both
Interspecific competition
A competition involving the use of limited
resources
Resource
They involved growing of Sorghasum nutans at low
density and high density
Those grown at low density grew to a larger
size at all nitrogen concentrations
Tilman and Cowan
As the stand of trees develops, more and more
biomass is composed of fewer and fewer
individuals
Self-thinning
studied interactions among planthoppers (Homoptera,
Delphacidae)
Denno and Roderick (1992)
Scientific name of Plamthopper
Prokelisia marginata
showed reduced survivorship, decreased body
length, and increased developmental time
P. marginata
used a field experiment to study the effects of a wide range of biotic interactions on the population biology of the terrestrial isopod Porcellio scaber
Grosholz (1992)
whose principal interest was interspecific competition, helped ensure a prominent place for the niche concept in modern ecology
G. F. Gause (1934)
states that two species with identical niches cannot coexist indefinitely.
Competitive exclusion principle
who linked differences in beak size and form among Darwin’s finches to differences in their feeding niches
David Lack (1946)
represented the feeding niches of Darwin’s finches by their beak morphology
Peter Grant (1986)
large ground finch scientific name
Geospiza magnirostris
medium ground finch SN
G. fortis
small ground finch SN
G. fuliginosa
can have significant ecological
and evolutionary influences on the niches of
species.
Competition
can have short -term ecological
effects on the niches of species by restricting
them to realized niches
Competition
the circumstance in
which two species differ more from each other
in geographic areas where they occur together
than where their distributions do not overlap
Character displacement
who list six
criteria that must be met to build a definitive
case for character displacement
Mark Taper and Ted Case (1992)
six criteria that must be met to build a definitive
case for character displacement
Morphological differences, genetic basis, different founder, known effect, demonstrated competition, and differences in the resources available.
enhances the fitness of one individual while reducing the fitness of the exploited individual.
Exploitative Interactions
consume live plant material but do not usually kill plants.
Herbivores
kill and consume other organisms
Predators
live on the tissues of their host, often reducing the fitness of the host, but not generally killing it.
Parasites
an insect whose larva consumes its host and kills it in the process
Parasitoid
induce disease, a debilitating condition, in their hosts
Pathogens
when one organism makes its living at the expense of another
Exploitation
who estimated that the approximately 500 known species occupying Lake Okeechobee, Florida, are linkedbyabout25,000 exploitative interactions.
K. E. Havens (1994)
spiny-headed worms
Acanthocephalans
small aquatic crutaceans
amiphods
Uninfected amphipods avoid the light shows
negative phototaxis
Infected amphipods swim toward light shows
positive phototaxis
Amphipod behavior remains unaltered until the acanthocephalan has reached a life stage
Cystacanth