chapter 54- comunity ecology Flashcards
What is a community
a group of populations of diff. species living in close proximity and interact
What are interspecific reactions
community interactions that are classified by whether they harm, help or have no effect on the particiaptants
6 interspecific reactions
- competition
- predation
- herbivory
- parasitism
- mutualism
- commensalism
describe 1. competition
(-/-)
an interaction that occurs when ind. of different species each use a resource that limits survival and reproduction of both ind.
example of 1. competition
weeds growing in garden compete w/ garden plants for soil and water
what is competitive exclusion
- when ind of two similar species compete for a resource and one pop. will use the resource leading to elimination of the other pop.
describe 2. predation
(+/-)- when predator of one species kills and eats an ind. of another species ( prey).
adaptations for both prey and predator
prey- ability to camouflage
predator- mimicry
what are two types of mimicry
bastian mimicry- harmless species pretends/mimics harmful species
- moth puffs head to mimic a venomous snake
mullerian mimicry- two harmful species resemble each other
hoverfly resembles wasp
( convergent evolution)
describe 3. herbivory
(+/-) when an ind. herbivore consumes part of plant that harms the plant but not enough to kill it
adaptations for plants and herbivore
plant- develops spine and thorns
- chemicals so that plant tastes bad
herbivore- special digestive enzyme to consume chemicals
describe 4. parasitism
(+/-) when a parasite derives it’s nourishment from another organism (a host)
two types of parasite
endoparasite- parasite lives inside host
ectoparasite- feed on the external surface of host ( ticks and lice)
describe 5. Mutualism
(+/+) interaction that benefits ind of both interacting species
- example squirrel eating fruits of a tree and spreading seeds, this helps trees grow.
commensalism (+/-)
one ind. benefits from an interaction and the other is not harmed or helped
what is symbiosis
when ind of 2 species live in direct close association
2 types of species diversity
- species richness
- relative abundance
what is species richness
number of species in a community
what is relative abundance
a species is abundant in one part of a habitat but absent in another part marked by an ecological disturbance, it is likely that a wildfire, flood, damaging wind event, or other disturbance limited the species’ abundance in the latter part.
Primary vs Secondary succession
soil not present after disturbance, and soil is present
what is a A foundation species
usually the most abundant
what is a keystone species
exerts the most influence on maintaining biodiversity.
two types of mutualism
obligate and facultative
what is facultative mutualism
is when they do not depend each other for surival
