Chapter 54 Community Ecology Flashcards
an assemblage of populations of various species living close enough for potential interaction
biological community
what kind of interaction is interspecific competition?
-/-
strong competition can lead to ______________, local elimination of a competing spevies
competitive exclusion
this states that two species competing for the same limiting resources cannot coexist in the same place
competitive exclusion principle
the total of a species use of biotic and abiotic resources is called the species…
ecological niche
can also be thought of an organisms ecological role
ecologically similar species can coexist in a community if there are one or more significant _________ in their niches
differences
differentiation of ecological niches, enabling similar species to coexist in a community
resource partitioning
the niche potentially occupied by that species
species fundamental niche
the niche actually occupied by that species
species’ realized niche
when both species are both normally nocturnal but one becomes diurnal
temporal partitioning
a tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species
ex: beak sizes
character displacement
effective chemical defense often exhibit bright warning coloration
aposematic coloration
ex: frogs
two or more unpalatable species resemble each other
ex: yellow jacket and bee
mullerian mimicry
palatable or harmless mimic resembles unpalatable mode or harmful model.
ex: coral snake and king snake
balesian mimicry
not part of a plant’s primary energy-generating metabolic pathway
secondary metabolites
ex: nicotine, morphine, caffeine
a relationship where two or more species live in direct and intimate contact with one another
what are the three types?
symbiosis
- parasitism
- mutualism
- commensalism
what are the two types of mutualism?
obligate- where one species cannot survive without the other
facultative- where both species can survive alone
one species benefits and the other is neither harmed nor helped
commensalism
is an interaction in which one species has positive effects on another species without direct and intimate contact +/+ or 0/+
ex: black rush makes the soil more hospitable for other plants species
facilitation
two fundamental features of community structure are species ______ and __________.
diversity, feeding relationships
species diversity depends on what two factors?
species richness- the number of different species in the community
relative abundance- the proportion each species represents of all individuals in the community
the ______ the value of Shannons index, the more diverse the community
higher
what are the benefits of a more diverse community?
- more productive
- more stable
- better able to withstand and recover from environmental stresses
- more resistant to invasive species
_________ link trophic levels from producers to top carnivores
food chains
-feeding relationships between organisms in a community
trophic structure
-a key factor in community dynamics
each food chain in a food web is usually only…
a few links long
what are the two hypotheses that attempt to explain food chain length?
- the energetic hypothesis
- dynamic stability hypothesis
the hypothesis that suggests that length is limited by inefficient energy transfer
-most data support this hypothesis
energetic hypothesis
the hypothesis that proposes that long food chains are less stable than short ones
dynamic stability hypothesis
- most abundant or have the highest biomass
- exert powerful control over the occurrence and distribution of other species
dominant species
-exert strong control on a community by their ecological roles, or niches
keystone species
- cause physical changes in the environment that affect community structure
ex: beavers
ecosystem engineers
describes communities as constantly changing after being buffeted by disturbances
nonequilibrium model
what type of disturbance can foster the greatest diversity
intermediate *intermediate disturbance hypothesis
disturbance that allows dominate species to exclude less competitive species
low level of disturbance
disturbance that excludes many slow-growing species
high level of disturbance
ealry-arriving species and later-arriving species may be linked in one of three processes…
- early arrivals may facilitate* the appearance of later species by making the environment favorable
- they may inhibit* the establishment of later species
- they may tolerate* later species but have no impact on their establishment
________ pathogens have been transferred from other animals to humans
zoonotic
many of today’s emerging human diseases are zoonotic
the transfer of pathogens can be direct or through an intermediate species called a…
vector
