Travel Reference
In-Depth Information
temperatures slow down decomposition, creating waterlogged peaty soils in valleys. Ter-
mites cannot live at these altitudes, so large earthworms and beetles take their place as de-
tritivores. The canopy can be as low as 10m, and in places the understorey gives way to
a thicket of shrubs. Mosses, lichens and ferns inhabit every branch and stone, and cover
theflooralongwithforestsucculentsand
Bulbophyllum
orchids.
Goodexamples:Marojejy
and Andringitra
.
DRY DECIDUOUS FOREST
The magnificent dry forests of the west once covered the
vast lowland plain west of the
hauts plateaux
. Now only a few patches remain, sharing the
coast with the mangroves, bordering the largest rivers of the south and dotted about the
plainsnearIsaloandinlandfromMahajanga.Theforestsupportsfarfewerspeciesthanthe
eastern rainforests but has higher levels of endemism. The trees are less densely arranged
and the canopy is typically 12-20m high.
The canopy leaves are shed during the seven or eight months of the dry season and a
carpet of leaves begins to accumulate on the forest floor shortly after the rains stop in May.
These decompose creating a thick humus layer in the soil. During this dry period much of
the wildlife goes to ground, quite literally: amphibians and insects bury themselves in the
soil to await the return of the rains.
Sifakas,sportivelemurs,brownlemursandtheubiquitousmouselemursareparticularly
in evidence. Vangas live in the canopy and tuneful vasa parrots make territories in the un-
derstorey. The deep litter layer is home to tenrecs, tortoises, boas and hog-nosed snakes.
Fossasandmongoosesregularlyrunalongtheirpatroltrails,sometimespursuingtheirprey
up into the canopy.
Good examples: Kirindy, Ankarafantsika and Berenty
.
INSELBERG AND
TSINGY
COMMUNITIES
In the west, where the underlying rocks
are exposed, localised communities of specialised plants and animals develop. Since rain
simply drains off, or through, the rocks, all the residents must be tolerant of desiccation.
Magnificent
Euphorbias, Aloes, Kalanchoes
and
Pachypodiums
grip on to tiny crevices,
bringing foliage and flowers to the rock face. The insects, birds and lemurs rely on these
for sustenance, only retreating in the heat of the day to rest beneath the trees in nearby
canyons.
Plants and animals are also to be found among the knife-edge pinnacles of the spectac-
ular limestone karst massifs known as
tsingy
(see
Click Here
)
. These bizarre eroded land-
scapes enable a complex mosaic of communities to live side-by-side. The towering pin-
nacles which sport the succulents are in fact the ornate roofs of extensive cave systems be-
low. These caves are inhabited by bats and rodents, with millions of insects and arachnids
feeding on the bat guano and each other. Blind cave fish share these dark subterranean
rivers with lurking cave crocodiles.
