A Feasibility Study for the Establishment of Xuan Lien Nature ...

Section 3 - Evaluation
has certainly been under-recorded. Therefore, it is not apparent at this stage whether or not low levels of known
biodiversity reflect a lower underlying level of biodiversity. However, it is clear that, with further study, the
known conservation value of the proposed nature reserve is likely to increase.
Xuan Lien proposed nature reserve contains 57% of the orders, 58% of the families and 16% of the species of
herpetile known for Vietnam. The herpetile diversity of Xuan Lien proposed nature reserve is comparable to that
of several other protected areas in northern and central Vietnam (Table 16). Only at Tam Dao National Park is
the number of herpetile species significantly greater than at Xuan Lien. Once again, this probably reflects the
greater amount of survey effort expended at Tam Dao.
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Table 16: Comparison of Herpetile Diversity of Xuan Lien Proposed Nature Reserve with other Areas in
Northern and Central Vietnam (Ranked)
Area Area (ha) Orders Families Species
1. Tam Dao National Park 19,000 6 21 103
2. Vu Quang Nature Reserve 55,630 4 19 62
3. Ba Vi National Park 7,000 4 16 62
4. Ben En National Park 16,643 4 20 60
5. Western Nghe An Province — 4 19 56
6. Xuan Lien Proposed Nature Reserve 23,610 4 19 53
7. Cuc Phuong National Park 25,000 4 17 53
The autumn butterfly fauna in northern and central Vietnam is characteristically diverse. The species diversity of
some families, such as the Pieridae, Papilionidae and Amathusiidae, varies between spring and autumn. For
example, observations at Ba Be National Park have shown a similar number of species in spring (April) and
autumn (November): 193 and 196, respectively. However, fluctuations in species diversity occurred within individual
families. For example, 22 Papilionidae species were recorded in spring and only nine species were recorded
in autumn. In contrast, more species of Nymphalidae were recorded in November (Monastyrskii et al. 1998).
Therefore, Cwhen =
comparing butterfly communities at different sites, only data for the autumn period (Septem-
s
ber to November) was used. The degree of similarity of between sites was measured using Sorenson’s Similarity
Index (Magurran 1988). The index, C , is given by the formula:
S
__2j__ Where: j = The shared species of two areas
(a + b) a = Number of species in area A
b = Number of species in area B
High values of C S indicate a high degree of similarity between the assemblages at a pair of sites. Comparisons
between different protected areas in northern and central Vietnam have been completed under each family and
for all butterfly communities (Table 17).
Table 17: Sorenson’s Similarity Index (CS) comparing Butterfly Species Composition in Xuan
Lien Proposed Nature Reserve with those in other Protected Areas in Northern and Central
Vietnam
Xuan Lien Vu Quang Pu Mat Ben En Cuc Phuong Ba Be Hoang Lien
All Species 0.544 0.500 0.484 0.463 0.439 0.264
Papilionidae 0.687 0.636 0.667 0.488 0.500 0.228
Pieridae 0.583 0.438 0.352 0.387 0.432 0.275
Danaidae 0.571 0.640 0.667 0.571 0.608 0.666
Nymphalidae 0.579 0.515 0.560 0.523 0.423 0.363
Satyridae 0.558 0.626 0.353 0.512 0.533 0.117
Amathusiidae 0.769 0.750 0.200 0.833 0.715 0.200
Riodinidae 0.800 0.545 0.400 0.600 0.444 0.545
Lycaenidae 0.509 0.358 0.235 0.343 0.400 0.250
Hesperiidae 0.286 0.353 0.400 0.395 0.319 0.038