The Northern Thailand–Laos moist deciduous forests ecoregion (WWF ID:IM0139) follows the upper course of the Nan River in northern Thailand and the Mekong River in Laos. This area has the highest proportion of tree cover in Thailand, with many forests dominated by Teak (Tectona grandis). The river valleys have been under pressure from human use: agriculture, teak plantations, and hunting have reduce plant and animal presence. Location and description The valleys in northern Thailand run north–south between a series a mountain ranges; this ecoregion's middle section covers the easternmost of these. The extensions to the west follow a west–east bend in the mountains, and the extension in the north follows the west–east course of the Mekong River in Laos. The valley floors are at 200–400 meters above sea level, and the transition to a montane ecosystem occurs around 800–1,000 meters. the highest point in the ecoregion is . The long, thin ridges of the ecoregion form a transition zone between the Luang Prabang montane rain forests to the south, the Northern Indochina subtropical forests to the north, and the Central Indochina dry forests to the west. Climate The climate of the ecoregion is Tropical savanna climate - dry winter (Köppen climate classification (Aw)). This climate is characterized by relatively even temperatures throughout the year, and a pronounced dry season. The driest month has less than 60 mm of precipitation, and is drier than the average month. Mean annual precipitation in the region is 1,000-1,200 mm. Flora and fauna About 75% of the region is closed forest, a mixture of deciduous broadleaf and evergreen types on the steep slopes. Another 10% is open forest. The forest has been degraded by human pressures, with selective logging taking much of the largest trees. The flat river valleys are mostly under cultivation. A study of a representative area of forest in Mae Yom National Park recorded 27% of the trees as Teak (Tectona grandis), 11% as Mai daeng (Xylia xylocarpa), 10% as Burma padauk (Pterocarpus macrocarpus), and 7% as Millettia (Millettia brandisiana). Bamboo is common in disturbed areas. Large mammals had been mostly eliminated in the wild by the early 1970s, and riverine habitats were disturbed by the construction of the Bhumibol Dam in the 1960s. Still, the ecoregion has one of the highest forest coverage rates in Southeast Asia, and the protected areas may support rare species. Protected areas Officially protected areas cover