Chapter 52 (exam 4) Flashcards
commensalism
when one species benifits but other is unaffected
competition
indviduals compete for the same resources, so both lower each others fitness
consumption
one organisms eats or absorbs nutrietns from another, increases consumers fitness but decreases victims fitness
mutualism
when two species interact that benefits both species fitness
intraspecific competition
competition that occurs between members of same species
- factor in density dependent growth
interspecific competition
when individuals from different species compete for or use the same resources
- direct or indirect
niche
range of resources that species is able to use or range of conditions it can tolerate
what happens when niches of two species overlap
interspecific competition occurs
what is the competitive exclusion principle
idea that two species cannot coexist in the same ecological niche in the same area cause one species will outcompete the other species
what happens when niches partially overlap?
individuals who use joint resources have the disadvantage relative to those that use other resources
fundamental niche
total theoretical range of environmental conditions a species can tolerate
realized niche
portion of fundamental niche that species actually occupies given limiting factors
niche differentiation
evolutionary change in resource use caused by competition
what is the difference between endoparasite and ectoparasite
an endoparasite consumes nutrients from inside its host, while an ectoparasite consumes nutrients outside its host
how does a parasitoid act as a consumption
it lays its eggs inside or on the body of its host where the eggs will hatch and kill the host
what is a coevolutionary arms race
series of adapatations observed in species that interact closely over time and affect each other’s fitness
constitutive defenses
defensive trait that is present even in the absence of consumers
what are they types of constitutive defenses
- cryptic coloration
- escape behavior
- toxins
- schooling/flocking
- armor/weapons
what is it called when a species has evolved to look or sound like another species
mimicry
what is the difference between Batesian and Mullerian mimicry
Batesian look dangerous but are not dangerous, Mullerian look dangerous and are dangerous
what are inducible defenses and why do they need to be used?
These are the physical, chemical, or behavioral defensive traits that are induced in response to a predator.
- have to be used cause constitutive defenses take a lot of energy to use
what type of defense is favored by natural selection
inducible
what is the main thing parasites have to able to do in order to thrive due to their small size
be transmitted to new hosts
what are the four key attributes of a community structure
- total number of species
- relative abundance and distribution of those species
- sum of interactions among all species
- physical attributes of the community
what are the two main methods of quantifying number of species in a community
- species richness: count how many species present in a given community
- species diversity: measure that incorporates both number of species and relative abundance
how do trophic levels work of a food web
producers are on “bottom” and consumers are on “top”
keystone species
species that has a very large impact on the other species in its ecosystem relative to its abundance
bottom-up influences on community structure
- when the amount of nutrients, sunlight, water, and other abiotic factors determine abundance of primary producers
- presence of species at “bottom” of food web
top-down influences on community structure
- when consumer limits a prey population
how does a trophic cascade occur
when changes in top-down control cause conspicuous effects two or three links away in a food web
- example= overfishing of sharks
what is a climax community
the stable, final community that develops from ecological succession and does not change over time
disturbance
any strong, short lived disruption to a community that changes the distribution of living and nonliving resources
what are the three factors of the function of disturbance
- type
- frequency
- severity
what is a community’s disturbance called
disturbance regime
what is the difference between resistance and resilience
Resistance is how much a community experiences an amount of change while resilience is how a community recovers after a disturbance
what are the two types of succession (recovery after organism are removed from a disturbance)
- primary: disturbance removes soil and its organisms along with the organisms above soil
- secondary: removes some/all organisms but leaves soil intact
which type of succession is more rapid
secondary because the soil is already present. In primary, the soil has been ripped away so it must be rebuilt.
what factors determine the pattern and rate of species replacement during succession?
- particular traits involved
- how species interact
- historical and environmental circumstances
During succession, existing species can have one of three effects on other species which are?
- facilitation: presence of early species makes conditions more favorable for arrival of later species
- tolerance: existing species do not affect probability that other species will become established
- inhibition: presence of one species inhibits the establishment or regrowth of another
how does weather have an effect on succession
variation in weather and climate causes different successional pathways to occur in sample place at different times
where should the most species-rich reserves be located
- relatively large areas
- located close to other relatively large habitat areas
what animals species diversity decline as latitude increases
birds, mammals, fish, reptiles, many aquatic and terrestrial invertebrates, and trees
what are the four broad categories for the hypothesis to explain the latitude diversity gradient
- abiotic: spatial hypotheses
- abiotic: energy hypotheses
- biotic: ecological interactions hypotheses
- biotic: evolutionary history hypotheses
