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GAP Analysis
RHII = 100 * (proportion of nonhabitat in state) * (proportion of nonhabitat
in status 1, 2, 3)
* (proportion
of nonhabitat in other status)
proportion of nonhabitat in state = (116216 – Total Potential Area) / 116216
proportion of nonhabitat in status 1, 2, 3 = (17218.43 – (Total [area] in
Status-1 + Status-2 + Status 3))
/ 17218.43
proportion of nonhabitat in other status = (98997.57 – (Total [area] in
Status-4 + Misc. status 4))
/ 98997.57
Sample Calculation:
proportion of nonhabitat in state = (116216 – 113982.1) / 116216 = 0.019
proportion of nonhabitat in status 1, 2, 3 = (17218.43 – (814.18 + 14004
+ 2187.9)) / 17218.43 = 0.012
proportion of nonhabitat in other status = (98997.57 – (274.28 + 96701.5))
/ 98997.57 = 0.020
RHII = 100 * (0.019) * (0.012) * (0.020) =
0.000046
very little conservation concern
Sample Calculation: northern water shrew
proportion of nonhabitat in state = (116216 – 1600.1) / 116216 = 0.986
proportion of nonhabitat in status 1, 2, 3 = (17218.43 – (28.21 + 408.3 +
82.67)) / 17218.43 = 0.970
proportion of nonhabitat in other status = (98997.57 – (2.16 + 1078.8)) /
98997.57 = 0.989
RHII = 100 * (0.986) * (0.970) * (0.989) =
94.59
very high conservation concern
gap analysis
A. goal—conserve things while still common
B. national
1. determine species distributions
2. determine conservation area distributions
3. look for overlap or gaps
C. PA
1. land cover and disturbance (urbanization) most important
2. GAP status lands
a) 1
(1) human disturbance prohibited and non-human disturbance not controlled
(2) wilderness areas, natural areas, wild areas, conservancies
(3) 1% of land
b) 2
(1) additional development prohibited
(2) state parks, state forests, state gamelands, national wildlife refuges
(3) 12% of land (much previously degraded)
c) 3
(1) additional development restricted
(2) national forest, national parks, national recreation areas
(3) 2% of land
d) 4—no specific provisions
3. high GAP
a) restricted species in unprotected habitat
b) wide-ranging species
4. regional habitat importance index (RHII)
a) overall habitat scarcity
b) scarcity of conserved habitat
c) scarcity of conservable habitat
d) sum for an index of landscape importance
e) leading landscape—important for multiple groups