b50 midterm 2 Flashcards
a non-trophic interaction between individuals, in which each is negatively affected by their shared use of a resource that limits their growth, survival, and/or reproduction
competition
competition between individuals of the same species
intraspecific competition
competition between members of different species
interspecific competition
occurs when one species directly interferes with its competitor’s ability to access a limited resource
interference competition
occurs when one species reduces the availability of a limiting resource to another species, simply by using it (indirect competition)
exploitation competition/resource competition
the study of ecological interactions between individuals of two or more species
Community ecology
interactions among multiple species
community ecology
what are the two types of interspecific competition
resource/exploitative and interference competition
competition between two species for a shared resource; by consuming or exploiting that resource, individuals of each species make it less available for individuals of other species
resource/exploitative competition
the full range of conditions (biotic and abiotic) and resources within which individuals of a species can survive and reproduce
fundamental niche
in the context of interspecific competition, the niche space that individuals of a species can access in the presence of their competitors
realized niche
an alteration in the way individuals of a species use resources in the presence of a competitor species
niche shift
the splitting of limited resources among individuals of two competing species
resource partitioning
the situation where no more individuals of a population or species are present in a location or on Earth; a possible long-term outcome of competition or predation
Extinction
the idea that past competition between two or more species may have altered resource use and interaction sufficiently that the species no longer compete; the only lingering signs of their previous competition are non-overlapping but similar resource use
Ghost of competition past
the restriction or removal of individuals of one species from a location by another species; a possible long-term outcome of competition or predation
Exclusion
a change in gene frequency in a population in which two coevolved species respond to each other’s adaptations over time
Evolution
the coexistence of individuals of two species in the same spatial location
sympatry
the spatially disjunct existence of two or more groups- that is, the existence of groups in separate and unconnected locations
allopatry
interspecific competition requires what
a limited resource
the study of multispecies interactions
community ecology
where are there more predator-prey relationships?
in the arctic because there is less biodiversity
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically. species
keystone species
most food chains are how many trophics high
4-5 (textbook says 6 but prof says its rare)
compared to lower trophic level organisms, top predators occur at higher densities or lower densities?
lower densities due to limits in energy transfer efficiency
where can we find humans on the food chain?
at the top
produced from within a system
endogenous
produced from outside a system
exogenous
Control of the energy flow in a food web by organisms at the basic tropic level (autotrophs). The abundance of autotrophs limits the amount of energy that is available to, and thus, the abundance of, species at higher trophic levels.
Bottom up control
Control of the energy flow in a food web by organisms at the upper trophic levels. By eating organisms at the lower trophic levels, the species at the upper trophic levels control the biomass and abundance of lower levels.
top down control
few primary producers, low biomass
oligotrophic
many primary producers, high biomass
eutrophic
adding phosphorous into the water, leads to algae production, why is this bad?
because algae deplete the water of oxygen, and fish die
what was the example of bottom up control used in lec 9
algae production in water, killing the fish because fertilizers use phosphorous and increase algae production but too much algae depletes the water of oxygen, so it is bottom up in the way that the lower levels (trophic level 1= algae) are affecting and limiting upper levels (ex. fish)
why do we need top predators such as wolves in an ecosystem?
because they keep herbivores and lower level consumers in check (brown world without wolves and green world with wolves)
food chains with odd numbers of trophic levels have _____ densities of primary producers
high (a green world)
food chains with even numbers of trophic levels have _____ densities of primary producers
low (a brown world)
something that feeds on dead organic material
detritivore
how can you determine a species diet
direct observation, gut content, and fecal analyses
variants of chemical elements that have differing numbers of neutrons in the atomic nucleus that do not decay radioactively over time
stable isotopes
ecologists use what to measure the ratio of different isotopes in tissue samples
mass spectrometer
species that have a disproportionally large effect on community structure, function, and/or diversity, relative to their own biomass and/or abundance
keystone species, occur in small numbers but have a large effect
species with a large effect on community structure, function, and/or diversity that is proportional to its biomass and/or abundance
foundation species, occur in large numbers and have a large effect
what is an example of a keystone species
mosquitos, you kill mosquitos, you kill a lot of other things as swell
bees, butterflies, a brick lol
species that create, modify, maintain, or destroy physical habitat
ecosystem engineer
both keystone and foundation species can be
ecosystem engineers
the overall effect of one species on a second species when both species interact with a third species or with a shared resource; the third species or shared resource mediates the interaction in such a way that the effect may even change in sign or direction.
indirect effect
an interaction between species in which the individuals of one species eat the individuals of the other.
trophic interaction
a feeding or eating level within a food chain or food web
trophic level
the direction in which nutrients and resources are moving up or down a food chain.
energy flow
a hierarchical linear set of interacting species depicting tropic interactions.
food chain