Slideshow 7 Flashcards
CONSUMER-RESOURCE LINK
A SPECIES eats RESOURCES (CONSUMER) and is itself eaten by other species
CONSUMER-RESOURCE INTERACTION NETWORKS
Fundamental building block from which increasingly complex food chains/
food webs can be constructed
is a food chain a CONSUMER-RESOURCE INTERACTION NETWORKS or CONSUMER-RESOURCE LINK
CONSUMER-RESOURCE LINK
is a food web a CONSUMER-RESOURCE INTERACTION NETWORKS or CONSUMER-RESOURCE LINK
CONSUMER-RESOURCE INTERACTION NETWORKS
What is the LOTKA-VOLTERRA MODEL
FORMED OF TWO KEY COMPONENTS (EQUATIONS)
1. RATE OF CHANGE OF PREY POPULATION
2. RATE OF CHANGE OF PREDATOR POPULATION
What is the rate of change of prey population
dN/d=rN-aNP
N = number of individuals
in prey population
R = prey’s per capita growth rate
aNP = the predators’ per capita attack rate
UNITS: The number of prey eaten per predator
per unit time
SO = SLOPE of the TYPE 1 response
What is the formula for the absence of prey, the predator population is assumed to decline exponentially:
dN/dt= -qp
qP is the predator’s per capita mortality rate (which is density independent)
UNITS: the number of deaths per predator per unit time
What are the 2 factors that PREDATOR POPULATION depends on
A| The number of PREY consumed with time = aNP
B| And on the efficiency of the PREDATOR of turning consumed prey in to NEW PREDATORS
This is assumed to equal a constant: f
What is the formula for the rate of change of the PREDATOR population
dN/dt = faNP-qp
THUS the birth rate of the PREDATOR population = faNP
what is an isocline
a line on a diagram or map connecting points of equal gradient or inclination
What is a zero growth isocline
define conditions when a population is
neither growing nor declining (rate of growth is ZERO):
what does dN/dt=0 when rN =aNP mean
prey population is in equilibrium
Does Predator or Prey population lag behind
Predator population always lags behind
prey population (one fourth)
How do we add density dependent effects to the lotka volterra model
ADD LOGISTIC GROWTH to model prey population
add (1-N/K)
New dN/dt=rN(1-N/K) - aNP
What happens when you add logistic growth to the prey population
The zero prey growth isocline
rotates clockwise
What is the ROSENZWEIG-MACARTHUR MODEL:
includes both (i)
Self limitation in prey or predator population (e.g. limited resources for prey)
(ii) A realistic predator functional response
ROSENZWEIG-MACARTHUR MODEL Rate of change of prey population
dN/dt= rN( 1- N/K) - aNP/1+ ahN
ROSENZWEIG-MACARTHUR MODEL Rate of change of predator population
dN/dt = (faNp/1+ahN) -qP
What changes in the prey isocline in ROSENZWEIG-MACARTHUR MODEL
Changes to hump shape
TYPE II functional response.
Prey per capita death rate declines with increase in prey density
When considering SINGLE predator and prey
