chapter 54 Flashcards
what is a community?
an assemblage of populations of various species living close enough for potential interactions
what is an ecological niche/role?
the sum of a species use of a/biotic resources
what is a niche?
everything a species use
what is a fundemental niche?
all factors that a species lives in
what is a realized niche?
where it really lives
what are interspecific interactions?
relationships between species in a community; competition, herbivory, symbiosis
what is predation?
refers to an interaction in which 1 species kills and eats the prey
what are some feeding adaptations?
claws, fangs, poison
what are some defensive adaptations?
behavioral: camouflage
chemical defenses: skunk smell
mechanical: spikes
what is crypsis?
blending in
what is aposomatism?
warning colors
what is homotypy?
prey resembles something that a predator thinks is inedible (leaf, dirt,etc)
what is mimicry?
mimics another species for protection
what is batesian mimicry?
harmless species mimics a harmful animal
what is mullerian mimicry?
two or more inedible species resemble each other ->predator wont go for anything that looks like them
how can mimicry be used by predators?
octopus can mimic the movement and appearance of marine animals
what is symbiosis?
relationship where two or more species live in direct and intimate contact with one another
what is parasitism?
the parasite derives nourishment from the host, who is harmed
what are some examples of microparasites?
viruses, protists; smaller than hosts
what are some examples of macroparasites?
leeches, fleas, mosquitos
what are endoparasites?
inside
what are ectoparasites?
outside
what are some human features that deal with ectoparasites?
hairlessness, standing upright, possible thumbs
what is mutualism?
interspecific interaction that benefits both species
what is obligate mutualism?
cannot live on their own
what is facultative mutualism?
both can live on their own
what is competitive exclusion?
local elimination of a competing species
what is resource partitioning?
differentiation of ecological niches, enabling similar species to coexist in a community
what is character displacement?
tendency for characteristics to be more divergent in sympatric (same area) populations of two species than in allopatric (different areas) populations of the same two species
what is commensalism?
one species benefits and the other is neither harmed nor helped
what is facilitation?
a plant interaction in which one species has positive effects on another species without direct and intimate contact.
what is species diversity?
the variety of organisms that make up the community
species diversity is made up of?
species richness and relative abundance
what is species richness?
number of species in a community
what is relative abundance?
proportion of each species
how can diversity be compared?
using the shannon diversity index
what is the equation of the shannon diversity index?
H=-(PalnPa + PblnPb + etc…)
p is the abundance of each species (probability)
higher h=more diversity
communities with ______ diversity are better
higher
what is biomass?
the total mass of all organisms
what are invasive species?
organisms that become established outside their native range
why are communities with higher diversity better?
more productive, more biomass
more stable in their productivity
better at withstanding environmental stresses
more resistant to invasive species
what is a trophic structure?
feeding relationships between organisms in a community
producers are _____
autotrophs
consumers are ______
heterotrophs
can you have a secondary producer?
no because producers dont have to eat others
what is energetic hypothesis?
food chain lengths are limited by inefficient energy transfer, only 10% of energy is transferred to the next level
why is is only 10% energy transferred?
consumer use that energy for other purposes so when others eat them they only get 10%
what are detritivores?
they eat dead material
why are detritvores important?
ultimate recyclers; plants are able to use nutrients over and over again
what are some examples of detritivores?
bacteria, fungi, mice, insects, worms
what are dominant species?
those that are the most abundant or have the highest biomass; usually the most competitive at exploiting resources or most successful at avoiding predators
why are invasive species bad?
usually become dominant very quick because theres no competition
what are keystone species?
exert strong control on a community by their ecological niches; alter biotic factors; affect environment just by being there
what are ecosystem engineers? (foundation species)
cause physical changes in the environment that affect community structure (beavers)
what is the bottom-up model?
proposes an unidirectional influence from lower to higher trophic levels
nutrients->plants->herbivores->predators
what is a top down model (trophic cascade) ?
predators->herbivores->plants->nutrients
what is a disturbance?
event that changes community, removes species+resources, flood, fire, earthquake
what is a nonequilibrium model?
communities constantly changing because of disturbances
a high level of disturbance _____ diversity because of stress
reduces
a low level of disturbance _____ diversity because of competition
reduces
what is the intermediate disturbance hypothesis?
moderate levels of disturbance can foster greater diversity than either high or low levels of disturbance
what is ecological succession?
predictable change in community after disturbance
what is primary succession?
starting over again from rock
what is secondary succession?
some soil left after disturbance
what is cyclical succession?
disturbance happens over and over again; depends on the disturbances
what is heterotrophic succession?
energy is greatest at the beginning, biomass and diversity DECREASE over time
what are the three stages of decomposition?
autolysis, putrefaction, and dry decay
what is autolysis?
fermentation changes; release of gases
what is putrefaction?
body becomes liquidy
what is dry decay?
all fluid is gone, bones and fur are left
what is moraine?
glacier debris that allows for growth
what are some ways to spot fake news?
based on peer reviewed work?
is the data cherry picked?
is denying climate change all they write about?
where was the news published?
