Madagascar succulent forests and Madagascar spiny thickets to the southwest and south. In four areas above elevation, the subhumid forests transition to the montane Madagascar ericoid thickets. Montagne d'Ambre near the northern tip of the island, contains a significant pocket of subhumid forest, surrounded at lower elevations by dry deciduous forest, as do Ankaratra, upland near Tsaratanana, Andringitra Massif, Ambohitantely Reserve, and the Ambohijanahary area. The subhumid forests ecoregion also includes the disjunct Analavelona and Isalo massifs to the southwest, surrounded by succulent forests at lower elevations. Flora The ecoregion is home to several distinct plant communities, which differ with elevation, rainfall, and soils. These include moist montane forest, sclerophyllous montane forest, tapia forest, rupicolous shrubland, and grassland. The original flora of ecoregion has been much altered by human use; extensive areas have been cleared for agriculture, grazing, and rice cultivation, and some exotic species such as Acacia and Eucalyptus have been introduced. Moist evergreen forests are less susceptible to fire than the sclerophyll forests and ericoid thickets. Frequent human-set fires have transformed some of the ecoregion's former forests into savannas and grasslands. Grassland now coves much of the highlands, but the extent to which the grasslands are the result of human intervention is still subject to debate. Moist montane forest occurs between 600–800 and 1300 meters elevation, and occasionally as high as 1800 m in sheltered locales. The mature tree canopy is generally closed, and 20 to 25 meters high. Trees are typically evergreen, and species of Tambourissa, Pterophylla (aka Weinmannia), Symphonia, Dombeya, Dilobeia, Dalbergia, Canarium, Diospyros, Eugenia, Protorhus, Grewia, Brachylaena, Schefflera, Polyscias, and Vernonia are most common. The conifer Podocarpus madagascariensis is also present. Trees of the genus Ephippiandra are largely confined to moist montane forest and some higher-altitude plant communities. There is a plentiful understory of shrubs and herbaceous plants. Epiphytes grow in large numbers on the canopy trees, including mosses, lichens, ferns, orchids (particularly species of Bulbophyllum), and species of Medinilla, Kalanchoe, Rhipsalis, and Peperomia. Sclerophyllous montane forest is low sclerophyllous (hard-leaved) forests and open-canopied woodlands from 1300 to 2000 meters elevation, dominated by small-leaved trees. The canopy is generally no higher than 10 to 13 meters, and can resemble a thicket. Common canopy trees include Dicoryphe viticoides, Tina isoneura, Razafimandimbisonia minor, and Baronia taratana. Gymnosperms, including species of Podocarpus, and bamboo can form pure stands. The trees and the ground are covered in mosses and