Fruit-frugivore interactions in a Malagasy littoral forest - Universiteit ...

Conservation
fragments, including both inland and coastal littoral forest. S9 has been subject to
numerous research projects since 1989 (Vincelette pers. comm.). This fragment contains
some recent tavy in its northern and north-eastern section (Bollen and Donati pers. obs.).
Logging has increased during the last years but ‘intact’ primary forest with important
lemur populations is still present. S17 is a long and narrow forest fragment located on a
dune system very close to the coast. The southern part is very degraded (Bollen and
Donati pers. obs.) but the northern part can still be considered very pristine, which is
probably due to its remote position as it is separated from the villages by a lake and an
estuarine system (Fig. 1). The extreme northern part (ca. 60ha) is owned by Mr. De
Heaulme and theoretically supervised by local guards. Both fragments, S9 and S17 are
very different in appearance and floral composition and include much of the biodiversity
present in the littoral forest. The conservation zones proposed by QMM involve 190ha of
S9 and almost complete S17. This will be enforced once the dina gets accepted by all
involved parties. Additionally we believe S6 is of extreme importance due to the presence
of the roost site of a colony of flying foxes, which are irreplaceable long distance seed
dispersers for numerous plant species. The forest fragment itself is extremely degraded
and victim to numerous unregulated forestry activities. All these fragments together
comprise about 1000ha of littoral forest. They lie within close proximity to one another
and comprise inland and coastal littoral forest, mangroves, dunes and marshes, sandy
beaches, a lake and an estuary providing important refuges for a wide variety of plant and
animal species (Fig. 1).
Several studies in Madagascar have demonstrated that it is better to protect a few
large fragments as opposed to several small ones. Ramanamanjato (2000) found that a
series of small littoral forest fragments does not provide the biodiversity of reptiles and
amphibians found in one or a few large fragments. The species number declines
substantially in fragments smaller than 200-300ha. As for birds, Raherilalao (2001)
showed that the number of bird species also decreases proportionally with the size of
forests blocks in Ranomafana. In addition, Ganzhorn et al. (2000) found that the number
of lemur species present in a fragment is related to its overall size. At the moment, Sainte
Luce still provides an important refuge for E. f. collaris (S9 density 0.38ind/ha, Banks
2002), which occurs only in the south-eastern region of Madagascar. Protection of the
remaining primary forest is of crucial importance in general because Ganzhorn and
Schmid (1998) found that even 40 year old secondary dry forests in western Madagascar
are unlikely to provide a suitable habitat even for the smallest seemingly least threatened
of all lemur species. As for protection measure all logging, hunting and slash and burn
practices should be banned from these fragments, so that ecosystems can recover. In
theory, the regional division of the Ministry of Water and Forests should control the
presence of these activities in the forest but there is a shortage of staff, finances and
means and the remoteness of Sainte Luce further contributes to the lack of an accurate
control system. The final management plan should clearly indicate what land could still be
used for these traditional activities allowing buffer zones close to the main population
centres. Ideally slash and burn practices should be replaced by more sustainable land
use practices in the zones adjacent to protected areas. Involvement of local people in
decision-making for conservation action plans is indispensable. Resource management
should be urgently improved and control systems should at least partially come from
within the villages.
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