list of figures - Terry Sunderland

Cameroon hinterland are well-known for their high levels of endemism and speciation
(Cheek et al., 1992; Thomas, 1994; Cable and Cheek, 1998) and these forests are
postulated to represent a Pleistocene refuge of some significance (Brenan, 1978;
Hamilton, 1981; Pannel and White, 1988; White, 1993; Maley, 1996; Robbrecht,
1996; Sosef, 1996; Morat and Lowry, 1997).
Table 6. Floristic similarity between the sample sites (all species)
Sorenson’s coefficient 8 Jaccard’s coefficient 9
Mokoko Campo Takamanda
Mokoko - 0.609 0.560
Campo 0.757 - 0.818
Takamanda 0.718 0.900 -
3.6.2 Rattan diversity and similarity
It is speculated that, to a certain degree, rattan diversity is positively correlated to
overall species diversity (Dransfield, 1979; Dransfield, 1992b). The results of this
study provide evidence to support this hypothesis. The Mokoko FR shows the greatest
diversity of rattan species (Shannon-Weaver index H = 1.09) followed by the
Takamanda FR (H = 1.01) and the Campo FR (H = 0.31). From these results, it is
clear that there is a strong positive correlation between overall floristic diversity and
rattan diversity (Pearsons correlation analysis r = 0.849, P < 0.01). In this respect, and
in the African context, preliminary study of the rattan diversity of an area may indeed
prove to be a reliable indicator of overall species diversity.
In terms of floristic similarity, however, the affinities between the rattan flora are
closer between Mokoko and Takamanda, and Mokoko and Campo, with very few
species shared between Takamanda and Campo. This is in contrast to the similarities
in the wider vegetation presented above. Although it is not clear why this might be the
case, the evolutionary history of the palm flora in Africa (as discussed in Chapter 1)
may account for these affinities. However, unlike the vegetation as a whole, the
7 Shannon-Weaver Diversity Index: H = -xpi 1n pi where p is the proportion of a particular species in
a sample which is multiplied by the natural logarithm of itself. H is derived by summing the product for
all the species in a sample (Hayak and Buzas, 1997).
8 Sorenson’s coefficient: CN = 2jN / (aN+bN), where aN is the number of individuals in site A, bN is the
number of individuals in site B and jN is the sum of the lower of the two abundances of species which
occur at the two sites (Hayak and Buzas, 1997).
9 Jaccard’s coefficient: Cj = j / (a=b-j), where j is the number of species common to both sites, a is the
number of species in site A, and b is the number of species in site B (Fowler et al., 1998).
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