Competition 2 Flashcards
what are the steps of lotka and volterra?
- begin with logistic model for pop growth
- assign subscripts to model parameters for each species –> 2 species
- apply the brake on exponential pop growth with intraspecific competition at k/2
what is the additional break and what does it signify
what is it called
alpha, it signifies interspecific competition
the competitive coefficent
what does it mean when alpha of a species is equal to 0?
same effect as intraspecific competition
what does it mean when alpha > 1
it means is has a greater effect than intraspecific competition
what does it mean when alpha < 1
it mean it has smaller effect that intraspecific competition
competetive coefficeint definition
magnitude of negative effects of individuals of one species on individuals of a second species (unitless, per capita metric)
the competetive coefficient,
the 2 sides
alpha 12 indicates the effect of one individual of species 2 has on the growth rate of species 1
alpha 21 indicates effect of one individual of species 1 has on the growth rate of species 2
N2 is always on the ZNGI
y axis
N1 always on the ZNGI
X-axis
changes in species 1 pop size (N1) indicated by: ZNGI
left-right arrow movements
where is N1 y-intercept? ZNGI
K1/alpha 12
Where is N1 x intercept ZNGI
K1
when is pop growing for N1?
on left side of line
when is pop decreasing for N1
right side of line
when is pop decreasing for N2
pop for N2 will increase
when is pop growing for N2?
below isocline
pop increase and decrease for N2 indicated by?
horizontal or vertical arrows
where is the y-intercept for N2?
K2
where is x-intercept for N2?
K2/alpha21
in order to tell if the 2 species coexist we need to?
combine the space state graphs of the 2 species
who wins the space state graph?,
whoever is on top wins, because they will eventually reach their carry capacity, and the other species will continue to decline
who wins if the pop sizes are in the state between the isoclines??
the dudee on the top wins, because their carrying capacity will be reached while other’s pop declines, leading to competitive exclusion
how does coexistance occur in the space state (ZNGI)
if lines cross
how to know if coexitance is stable or unstable?
carrying capacities(K1,K2) have to be smaller than k/alpha ratios
what is it called when one species outcompetes a mf
competitive exclusion
