topic 10 Flashcards
mutualism
where both orgs benefit from an interaction
commensalism
where one org benefits but the other is unaffected
exploitation
where one org benefits but the other is harmed.
parasites, predation, herbivory
neutralism
both orgs are unaffected
amensalism
where one org is unaffected but the other is harmed
competition
where both orgs are negatively effected
Commonly occurs when orgs use the same limited resource.
why types of competition are there
inter: among members of diff spices
intra: among members of the same species
interference: the direct aggressive interaction between indivs
exploitative competition: to secure resources first: avoivd direct interactions
what is interference comp relate to
intrasecula competion
the fight for mates between males
what is an example of exploitative competition
the self thinning of a tree population
the reduction of plant density do to the increase in plant biomass
powered by intraspecific comp
what results due to the competition of niches
often the niche will shrink/ narrow for the 2 competing species. This may alter distributions and drive speciation
this is coherent with the competitive exclusion principle: no 2 species can coexists in the same niche indefinitely
is what ways can the competitive exclusion principle be violated
in some cases species are able to co-exists via
spatial heterogeneity in the strength of competition
variation in competitive abilities of indives
competitive equavialence (on avg the outcome is unpredicatableO
what is herbivory
the consumption of living plants for energy
plant may recover or die
what is predation
the kill and consumption of organisms by a predator
what is the effect herbivores have on plants
reduced growth rate and reproduction of plant
this is often due to the large amount they need to eat to match their C:N ratio requirements (plants have the lowest nitrogen stores)
why did plants eveolve defense mechanisms
from the selective pressures exterted from herbivours.
what are the three mech for plant defence
increased growth (tolerance)- to outgrow the range and return rate of the herbivore
chemical defense (resistance)- poison production
morphological defense (resistance)- thors or hair to repel orgs
what are chemical plant defenses
toxins - to kill, impair or repel herbivores
digestions reducing substances - inhibit the breakdown of plant proteins by digestive enzymes
may be: constitutive: cont productions independent of the environment
induced: inc rapidly in response to plant damage by herbivore
what are morphological defenses
used to increase the time it takes to eat or digest plant, making them unappealing or unfit to the optimal foraging theory
what are trichomes
fine hairs that grow on the epidermis of plants
a morphological defense
the predator prey relationship
each population will mimic the abundance of the other. Large populations of prey will allow the predator population to increase until prey populations decline. and vice versa.
during times of predator reduction, the vigilance of the prey decreases which:
increases foraging time
increase E for report
allows for the aggregation of prey species
what is the landscape of fear
the noncomsumptive effects that predators have on prey for the perceived risk of being killed (which changes prey response)
behavioral effect (change in foraging and reprod)
physiological effect (stress lvls)
morphological effects (appearance (phenotypic plasticity))
what are some morphological effects of the landscape of fear
camouflage: blending into the environ by evolving particular color patterns
standing out : the use of conspicuous aposematic coloration (warning) to communicate unpalatability
what is basian mimicry
when a nontoxic speices will have coloration similar to that of a nontoxic species living in the same area
what is mullerian mimicry
when 2 or more distasteful or dangerous spepices resemble each other
what is the co-evolutionary race
the constant cycle of prey and predators adapting to evolve better defences or foraging strategies
what is an ecosystem?
a biological community and its associated physical and chemical envrion
may have discrete boundaries but in many cases will change in response to a environmental gradient
this is most due to the abiotic factors influencing the types of vegetation or organisms that are able to survive in an area
what factors influence a community
temp, precip lvl, and land surface
species diversity vs richness
diversit: number of seices and thier relative abundance
richness: the number od species in. community.
what is one of the most fundamental aspects to a community structure?
species richenss
alpha diversity
the meassure of local diveristy (small area)
beta diversity
the measure in diff among communities in a region or landscape (how patches are diff from each other)
gamma diversity
the measure of regional or landscape diversity (total diversity in an entire area (all habitats))
guild
a group of orgs that live in a similar way
eating seeds
life form
a body or growth pattern that characterizes a kind of organism
algae, vertebrate, vasc plants
functional group
collection of orgs wth similar ecological, morph, physiological, or behavioral features or trophic characteristics
where is species diversity highest
in complex environments . this is beciase more complex nechies are available for more species to occupy
ex. taller forests can host a wider variety fo birds
what does the shannon wiener index look to achieve
a method used to capture a screenshot of a communities diversity.
looks at the number and evenness of species
the smallest value is 0 and the value forever increases with increasing richness and evenness
what is an island
an ecosystem that is drastically different from its surroundings
keystone species
have disproportionate influence on the organization of a biological community
very few indivs or biomass
many examples focuses on top predators
what are ecosystem engineers
a keystone species that have the abilty, to creat, destroy or alter existing habitats
