Populations and interactions Flashcards
Populations
- a group of individuals of one species
- defined by the number of individuals that compose it
Interactions
- influence of one population over another via a plethora of drivers
- defined by relative position within food webs and space-time
resource avaiblity
- drives population size
- but also acts as a determinant of individual life history
Semelparous and iteroparous
- two classes of possible reproductive strategies available to living organisms.
R selected
Semelparous
High fecundity, low body size, early maturity, wide dispersal
K selected
Iteroparous
Low fecundity, large body size, late maturity, long life expectancy
Fecundity
the ability to produce an abundance of offspring or new growth; fertility.
intraspecific competition
a group of organisms capable of interbreeding and producing fertile offspring
- similarity of morphology or ecological niche
interspecific (Competitive Exclusion Principle)
if 2 competing species co-exist in a stable environment then they so so as a result of niche differentiation
Predation
one species feeds on another: enhances fitness of predator but reduces fitness of prey
Parasitism
one species utilises another: enhances fitness of parasite but reduces fitness of host
Mutualism
two species provide resources or services to each other: enhances fitness of both species
Commensalism
one species receives a benefit from another species enhances fitness of one species: no effect of fitness of the other species
Interactions
- act across several trophic levels
- affect system productivity
Managing populations
- harvesting a species is an example of predation carries all the signs of predator-prey relationship
- output maximisation, keep population just below carrying capacity
- effect of thinning on forest productivity
