Madagascar lowland forests
The ecoregion constitutes a narrow strip of lowland forests between Madagascar's east coast and the mountainous central highlands, from sea level to 800 meters elevation. It covers an area of approximately 112,600 square kilometers. The ecoregion is under the direct influence of the moist southeast trade winds, which maintain a warm, humid climate.
The lowland forests extend from Marojejy in the north to the southeast corner of the island. At the northern edge of ecoregion around Vohemar, the moist forests transition to the drier Madagascar dry deciduous forests ecoregion. To the east, at approximately 800 meters elevation, the lowland forests transition gradually to the Madagascar subhumid forests ecoregion. The southern end of the ecoregion lies at the crest of the Anosyennes Mountains, where a narrow belt of dry transitional forest marks the transition to the xeric Madagascar spiny thickets ecoregion in the mountains' rain shadow.
The lowland forests are characterized by dense evergreen forests, with a canopy exceeding 30 meters. Typical canopy species include Dalbergia, Diospyros, Ocotea, Symphonia, and Tambourissa; emergents of Canarium, Albizia, and Brochoneura acuminata rise above the canopy. The lowland forests have a rich diversity of Pandanus, bamboo, and epiphytic orchid species.
Madagascar's lowland rainforests have been preserved generally better than the high central plateau, presumably due to historically less population density and longer distance to the capital city via marginal highway. There has been widespread slash-and-burn activity in the lowland rainforests, reducing certain forest habitat and applying pressure to some endangered species. Slash-and-burn is a method sometimes used by shifting cultivators to create short term yields from marginal soils. When practiced repeatedly, or without intervening fallow periods, the nutrient-poor soils may be exhausted or eroded to an unproductive state. These habitat loss impacts are especially significant because of the inherent biodiversity and high endemism of these rainforests. An interesting feature of these rainforests is the presence of Pachypodium habitats, often associated with xeric islands created by locally efficient drainage.
The lowland forests represent a great reservoir of diversity and endemism. nearly all of Madagascar's endemic mammal genera are represented there, including all five families of lemurs. 15 species and subspecies of lemurs are endemic and near-endemic to the ecoregion, including the Aye-aye (Daubentonia madagascariensis), the Hairy-eared Dwarf Lemur (Allocebus trichotis), both species of ruffed lemurs (Varecia variegata, V. rubra), the Indri (Indri indri), the Eastern Woolly Lemur (Avahi laniger), the Diademed Sifaka (Propithecus diadema), Milne-Edwards' Sifaka (P. edwardsi), the Golden Bamboo Lemur (Hapalemur aureus), the Greater Bamboo Lemur (Prolemur simus), the Gray-headed Lemur (Eulemur cinereiceps), the Collared Brown Lemur (E. collaris), and the Red-bellied Lemur (E. rubriventer).
It is estimated that only a third of the original lowland forest remains intact. Seven percent of the lowland forests that remain are protected in national parks and reserves, including Masoala National Park, Mananara Biosphere Reserve (including Verezanantsoro National Park), Ambatovaky Special Reserve, and Zahamena Integral Nature Reserve and National Park.