Database Reference
In-Depth Information
extrema solutions for B exist. Run a series of sensitivity tests on KS and Q to
explore their impact on the system's dynamics.
2. (a) Change the initial conditions for the spruce-budworm dynamics model in a
series of sensitivity runs. Explain the results.
(b) Introduce an exogenous shock into your model that (at a random time) re-sets
the budworm population to its initial condition. What are the impacts on the
overall results? Explain your findings.
SPRUCE BUDWORM DYNAMICS
B(t)
=
B(t
−
dt)
+
(
∆
B) * dt
INIT B
=
3
{
Spruce Budworm per Unit Area
}
INFLOWS:
∆
C*B
∧
2/((K1 * S)ˆ2
B
∧
2)
B
=
GR*B*(1
−
B/K/S)
−
+
{
Spruce Budworm
per Unit Area per Time Period
}
E(t)
=
E(t
−
dt)
+
(
∆
E) * dt
INIT E
=
.95
{
Percentage of Foliage Cover
}
INFLOWS:
∆
E
=
RE*E*(1
−
E)
−
P*B*Eˆ2/S
{
Change in Percentage of Foliage Cover
per Time Period
}
S(t)
=
S(t
−
dt)
+
(
∆
S) * dt
INIT S
=
2.5
{
Habitat Density
}
INFLOWS:
∆
S
=
RS*S*(1
−
S/KS/E)
{
Habitat Density Change per Time Period
}
C
=
1
R
*(1
F
=
−
X/Q)
X
∧
2)
G
=
X/(1
+
GR
Spruce Budworm per Unit Area per Spruce Budworm per Unit Area per
Time Period
=
2
{
}
K
=
1
K1
=
.1
KS
=
2.5
P
=
.01
Q
=
K/K1
R
=
GR * K1 * S/C
R
=
GR*K1*KS/C
RE
Change in Percentage of Foliage Cover per Percentage Foliage Cover
Time Period
=
2
{
}
RS
=
3
{
Habitat Density Change per Habitat Density Change per Time Period
}
X
=
TIME
