Environmental Engineering Reference
In-Depth Information
(a)
(b)
30
25
20
15
10
5
0
60
50
40
30
20
10
0
2-6
7-10
11 -14 15 -18 19 - 22 23 - 26 27- 30 31-35
2299 -
2447
2448 -
2595
2596 -
2743
2744 -
2891
2892 -
3039
3040 -
3187
3188 -
3335
3336 -
3483
Slope (
°
)
Elevation (m)
(c)
(d)
60
50
40
30
20
10
0
100
80
60
40
20
0
N-NE
NE-E
E-SE
SE-S
S-SW SW-W W-NW NW-N
0-
200
401 -
600
801 -
1000
1201 -
1400
1601 -
1800
2001 -
2200
2401 -
2600
Aspect
Nearness to streams (m)
Fig. 2.6
Observed frequency distributions of 149 overwintering monarch butterfl y colonies in central Mexico in relation to
(a) slope, (b) elevation, (c) aspect and (d) proximity to a stream. (From Begon et al., 2006, after Bojorquez-Tapia et al.,
2003.)
(a)
(b)
(c)
Fig. 2.7
Optimal distribution in the mountains of central Mexico of overwintering monarch
butterfl y reserves (shaded areas) according to three scenarios: (a) area constraint of 4500 ha;
(b) area constraint of 16,000 ha; (c) no are a con st raint (area included is 21,727 ha). Black lines
are the boundaries between river catchment areas. Scenario (c) was accepted by the authorities
for the design of Mexico's 'Monarch Butterfl y Biosphere Reserve'. (From Begon et al., 2006, after
Bojorquez-Tapia et al., 2003.)
altitude, close to the coastal fringe or waterways, which do not receive direct sun-
light. A positive association with increasing habitat complexity also suggested a
preference for areas containing tree and shrub canopy as well as herbaceous ground
cover. Of the total study area, 16% was predicted as suitable habitat that needs to
be protected.
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