Madagascar belongs to the
Afrotropical realm. With its neighboring
Indian Ocean islands, it has been classified by
botanist Armen Takhtajan as
Madagascan Region, and in
phytogeography it is the floristic
phytochorion Madagascan Subkingdom in the
Paleotropical Kingdom. Madagascar features very contrasting topography, climate, and geology. A mountain range on the east, rising to at its highest point, captures most rainfall brought in by
trade winds from the Indian Ocean. Consequently, the eastern belt harbours most of the humid forests, while precipitation decreases to the west. The
rain shadow region in the southwest has a
sub-arid climate. Temperatures are highest on the west coast, with annual means of up to , while the high massifs have a cool climate, with a annual mean locally. Geology features mainly
igneous and
metamorphic basement rocks, with some
lava and
quartzite in the central and eastern plateaus, while the western part has belts of
sandstone,
limestone (including the
tsingy formations), and unconsolidated sand. ==Terrestrial ecoregions==