Database Reference
In-Depth Information
7.2 Questions and Tasks
1. Could residual benefits occur from the large mast event that carried over because
the tick burden carrying capacities were not limiting?
2. What would happen if mice and/or deer were excluded from the model forest?
3. What would happen if the deer population density changed in response to disease,
predation, and harvesting?
4. What would happen if mice were allowed to emigrate / immigrate into the model?
5. The tick burdens on mice for the model of this chapter are based on Illinois data,
and mouse tick burdens are higher on the East Coast. What if the model employed
higher daily tick burdens on mice?
LYME DISEASE
Deer Movement
DEER(t)
=
DEER(t
−
dt)
INIT DEER
=
35
{
deer per 10 ha
}
ACORNS AVA I L A B L E
=
ABS(SINWAVE(ACORN MAST STORE NUMBER,(38
−
25)*2))*2
DEER FOREST
DEER*DEER PERCENT HABITAT USE/100
DEER MODEL FOREST
=
=
IF PROB IN MODEL Ha
<
0 THEN 0 ELSE
DEER FOREST * PROB IN MODEL Ha
PROB IN MODEL Ha
1 sq. km, 6 ha nonforested,
4 ha forested. Model is in 1 of the 4 forested hectares, so there is a 1 in 4 (25%)
probability of being in the model forest.
=
0.25
{
Deer are in 10 ha
=
}
DEER PERCENT HABITAT USE
GRAPH(ACORNS AVAILABLE)
(0.00, 7.00), (10.0, 12.5), (20.0, 18.0), (30.0, 24.0), (40.0, 30.5), (50.0, 37.0),
(60.0, 44.0), (70.0, 50.5), (80.0, 57.5), (90.0, 64.0), (100, 70.5)
=
Mouse Population Dynamics
MOUSE K SUMMER CAP(t)
=
MOUSE K SUMMER CAP(t
−
dt)
+
(MOUSE S TO S SUMMER CAP
−
MOUSE CHANGE S TO S CAP) * dt
INIT MOUSE K SUMMER CAP
=
20
INFLOWS:
MOUSE S TO S SUMMER CAP
=
MOUSE NEXT SUMMER POP DENSITY
OUTFLOWS:
MOUSE CHANGE S TO S CAP
25) THEN 0 ELSE IF
(WEEK COUNTER=25) THEN MOUSE K SUMMER CAP ELSE 0
=
IF (TIME
<
N(t)
=
N(t
−
dt)
+
(dN) * dt
INIT N
2
INFLOWS:
dN
=
=
R*N*(1-(N/K))
{
Individuals per Week
}
