Dry Forest Ecology | WWF

Dry Forest Ecology



The Lower Mekong Dry Forest Ecoregion is characterized by a mosaic of habitats. The main forest type is deciduous dipterocarp forest. On higher quality soils or at higher elevation, areas of mixed deciduous forest and semi-evergreen forest occur. This mosaic of forest types is one of the reasons why such a large quantity and diversity of species are home to this landscape – the diverse forest patches act as key resource areas and refugia for a lot of wildlife.
Deciduous dipterocarp forests typically have an open canopy combined with a grassy understorey. Members of the forest’s namesake family Dipterocarpaceae dominate the vegetation. While all other Dipterocarp-trees are evergreen, the six species in the dry forest are the only ones that lose their leaves during the dryer months of November to April. This is likely to be an adaptation to the region’s climate with its strong, extended wet and dry seasons – shedding the leaves decreases the trees’ surface area and reduces the amount of water that the trees lose due to transpiration.

Semi-evergreen forests have a taller and more multilayered forest structure than deciduous dipterocarp forests. While such forests are similar in structure to lowland evergreen rain forest, they grow in areas with lower and more seasonal rainfall and are characterized by lower species diversity. Bamboos are common in the semi-evergreen forests of Cambodia’s Eastern Plains Landscape, especially along seasonal waterways and after disturbance. Within the Dry Forests Ecoregion, semi-evergreen forest patches are essential in providing shelter to large mammals and key resources to many species.

Interspersed within these forests are seasonally inundated wetlands; natural clearings that provide sources of food and water for a wide variety of wildlife, especially during the latter stages of the dry season. These wetlands, along with scattered permanent pools along seasonal river beds, form a crucial resource network throughout the Dry Forests ecoregion, especially in the Eastern Plains and help to maintain many of its ecological processes.
 
	© Arnulf Koehncke / WWF-Cambodia
Seasonal waterholes, so-called trapeang, are an essential feature of dry forest ecology in Cambodia's Eastern Plains Landscape
© Arnulf Koehncke / WWF-Cambodia
 
	© Arnulf Koehncke / WWF-Cambodia
Open dry deciduous forest in Mondulkiri Protected Forest within Cambodia's Eastern Plains Landscape
© Arnulf Koehncke / WWF-Cambodia
 
	© Phan Channa / WWF-Cambodia
Denser semi-evergreen forest in Phnom Prich Wildlife Sanctuary within Cambodia's Eastern Plains Landscape
© Phan Channa / WWF-Cambodia