The Kingdom of Cambodia is in the southern part of the Indochinese Peninsula in the larger Southeast Asian region. The country covers a total area of 181,035 square kilometers, and is bordered by Thailand, Laos, Vietnam, and the Gulf of Thailand. Cambodia also has 443 kilometers of coastline along the Gulf of Thailand. The landscape of Cambodia is characterized by low-lying plains that are surrounded by lowland and upland mountains. The country is dominated by monsoon climate known for tropical wet and dry. The rainy season runs from May to October why the dry season lasts from November to April. Cambodia is divided into four ecological regions, each of which are looked at below.
Annamite Range Moist Forests
The Annamite Range Moist Forests ecoregion covers parts of Laos, Vietnam, and the northeastern edges of Cambodia. The ecoregion is characterized by abrupt changes in climatic conditions, especially along the mountain crest. The forest canopy heights reach around 15 to 25 meters, and are dominated by such plant life elements including Myrtaceae, Lauraceae, Elaeocarpaceae, and Fagaceae. The large canopies do not allow light penetration to the ground level leading to little or no undergrowth vegetation. The Annamite Range Moist Forests are home to 134 species of both endemic and near-endemic mammals, 525 species of birds, several species of reptiles, and other birds. More than 50% of this ecoregion has been cleared with logging and firewood harvesting being the major threats.
Cardamom Mountains Moist Forests
The Cardamom Mountains Moist Forests cover both the Cardamom Mountains and the Elephant Range in the southwestern parts of Cambodia. The region receives a mean annual rainfall of 5000 millimeters in areas around the ranges and 2,000 millimeters along the coast. Cardamom Mountains Moist Forests is considered to be one of the species-rich ecoregions of Cambodia. In terms of flora, the composition of the plant life of this ecoregion is composed of evergreen forest plant species including Hopea pierrei, Shorea hypochra, and Dipterocarpus costatus. The ecoregion is home to over 100 mammals with elephants being the most important mammals in the area. 450 species of birds and several reptiles are also found in this ecological region. The ecoregion is underutilized and unexplored, and much of the area remains intact. Much of the area is protected and with effective management and workforce. However, cases of illegal logging are being reported.
Central Indochina Dry Forests
The Central Indochina Dry Forests are widespread in the arid plains of Cambodia. The ecoregion forms a woodland community of forests called forest Claire, which is dominated by deciduous trees. The dominant species of deciduous trees is the Dipterocarpaceae. The ecoregion has 167 species of mammals with the majority being threatened large vertebrates. There are also over 500 species of birds and other plants found in this region. The ecoregion is threatened by human activities such as land clearing for settlement.
The Mekong River flows through six countries, including China, Vietnam, Thailand, Myanmar, Laos, and Cambodia. The Mekong River is the world’s 12th longest river. The Mekong enters Cambodia with 95% of the flow already joined the river. The ecoregion is characterized by a high diversity of habitats including deciduous forests, grasslands, wetlands, and riparian environments. The habitats are home to 20,000 species of plants, 1,200 species of birds, 800 species of reptiles, and 430 species of mammals. The series of hydroelectric dams constructed along the river has impacted the ecosystem negatively. Sand mining and over-fishing are also common threats to this ecosystem.
The ecological regions of Cambodia are classified under one of two Biomes, namely the terrestrial Tropical and Subtropical Moist Broadleaf Forest biome and the Freshwater biome in the case of the Mekong River.