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BBOP Pilot Project Case Study – Ambatovy Project
Appendix 5: Vulnerability Index
VULNERABILITY
can be expressed based on:
Geographical range (largely, more restricted),
Level of habitat types dependence (more ubiquiste to stenocene species etc.), and
Abundance indices (rare to common) (Kattan 1992; Rabinowitz
et al.
1986).
The approach used allows the offset planner to attribute an index score in each cell of the matrix in order to
represent the vulnerability level of each species based on above parameters. For a community, the
percentage of species constituting its total number could be included in a cell in order to indicate how
vulnerable a community is. The original concept of the vulnerability matrix following (Rabinowitz
et al
. 1986) is
presented below, where Vi is the vulnerability index.
Range (geographical distribution)
Large
Restricted
Habitat type
dependence level
Ubiquiste
Stenocene
Ubiquiste
Stenocene
Common
Vi=8
Vi=6
Vi=4
Vi=2
Abundance
Rare
Vi=7
Vi=5
Vi=3
Vi=1
In order to ensure that the matrix is properly used as part of the calculation of loss and gain of biodiversity, the
following points must be taken into consideration:
Since the
BENCHMARK
approach is based on the principle that higher values are better in the habitat
hectares calculations, higher index values should be given with increased vulnerability (e.g. Vi= 1 becomes
Vi = 8 etc…).
The BBOP ‘
Key Biodiversity Component Matrix (KBCM) ‘Irreplaceability’ level (Widespread, Localised,
SITE
ENDEMIC
) will be used instead of ‘
Range’ (geographical distribution
); and
The KBCM ‘
Significance level
’
Global
column will consider (CR, EN, VU, NT) instead of using ‘
habitat type
dependence level’
.
Thus the Vulnerability matrix concept proposed for BBOP is:
Irreplaceability :
Widespread
Localised
Site endemic
Abundance level:
Common Rare
Common Rare
Common Rare
LC
1
4
11
16
21
26
NT
2
5
12
17
22
27
VU
3
6
13
18
23
28
EN
7
8
14
19
24
29
IUCN Status
CR
9
10
15
20
25
30
