The Guinean forest-savanna, also known as the Guinean forest-savanna transition, is a distinctive ecological region located in West Africa. It stretches across several countries including Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Togo, Benin, Nigeria, and Cameroon. This region is characterized by a unique blend of forested areas and savannas, creating a diverse and dynamic landscape. It is an ecoregion of West Africa, a band of interlaced forest, savanna, and grassland running east to west and dividing the tropical moist forests near the coast from the West Sudanian savanna of the interior.

Setting

The Guinean forest–savanna mosaic covers an area of 673,600 km2, extending from western Senegal to eastern Nigeria, and including portions of Gambia, Guinea Bissau, Guinea, Sierra Leone, Côte d'Ivoire, Ghana, Togo, Benin and Cameroon. The Cameroon Highlands of eastern Nigeria and Cameroon separate the Guinean forest–savanna mosaic from the Northern Congolian forest–savanna mosaic, which lies to the east. The Dahomey Gap is a region of Togo and Benin where the forest-savanna mosaic extends to the coast, and separates the Upper Guinean forests of Guinea, Sierra Leone, Liberia, Côte d'Ivoire, and Ghana from the Lower Guinean forests of Nigeria and Cameroon.

Climate

The climate in this region varies depending on the specific location, but it generally experiences a tropical climate with distinct wet and dry seasons. The wet season brings heavy rainfall, while the dry season is characterized by lower precipitation and drier conditions. This ecoregion is situated in the humid tropical savanna zone, where the average yearly high temperatures range from 30 to 33°C and the lows range from 14 to 21°C. The annual rainfall typically falls between 1,600 and 2,000 mm, although there are areas in the Dahomey Gap that receive 1,000 mm or less annually. The Guinean savanna mosaic represents a critical ecological transition zone between the dense, evergreen rainforests to the south and the more open, tree-dotted savannas to the north. This transition creates a unique mix of plant and animal species adapted to varying ecological conditions. Like many ecosystems worldwide, the Guinean forest-savanna mosaic is susceptible to the impacts of climate change. Altered rainfall patterns, increased temperatures, and more frequent extreme weather events have affected the health and composition of this biome.

Biodiversity

The Guinean forest–savanna mosaic is known for its high biological diversity. It is home to a wide range of plant and animal species, including many endemic species that are found nowhere else in the world. Some iconic species found here include chimpanzees, pygmy hippos, forest elephants, and various species of primates and birds. They also include several species of primates, reptiles, amphibians, and plants that have evolved in isolation within this region.

Vegetation

Flora

This biome is characterized by a mix of forested areas and open savannas. It is often referred to as a mosaic because it consists of a patchwork of different vegetation types. In the forested areas, you can find a mix of evergreen and deciduous trees, while the savanna regions feature grasslands and scattered trees. In terms of plant life, it contains a mix of tree species such as mahogany, iroko, and various species of acacia, alongside grasses and shrubs common to savannas. The region is mainly grassland crossed with trees growing alongside streams and on hillsides, with the constantly occurring fires keeping back the growth of trees in open country. Lophira lanceolata is one of the tree species found that is more resistant to fire than many others.

Fauna

The mixture of forest and grassland provide habitat for a range of species from large mammals such as African leopard, forest elephants, hippopotamus and antelopes such as the red-flanked duiker to the common tortoise as well as more localised species including patas monkeys and Ghana worm lizards (Amphisbaenia). The wetlands in the region are rich in birdlife, including iris glossy starling and black crowned crane.

Human settlement

The ecoregion covers large areas of many West African nations including:

Threats and Conservation

Like many tropical ecosystems, this mosaic is under threat from various human activities. Deforestation due to logging, agriculture expansion, and mining operations pose significant challenges to its conservation. Additionally, infrastructure development and road construction can fragment habitats, making it difficult for wildlife to move between different areas.

Conservation Initiatives

Conservation organizations and governments in the region have recognized the importance of preserving the Guinean forest-savanna mosaic. Efforts have been made to establish protected areas and national parks, such as Taï National Park in Ivory Coast and Gola Rainforest National Park in Sierra Leone and Liberia.

Protected areas

The Guinean forest-savanna mosaic is a biologically diverse and ecologically significant region in West Africa. Its unique blend of forest and savanna habitats, along with its endemic species, make it an area of global importance for conservation efforts. A 2017 assessment found that 107,116 km2, or 16%, of the ecoregion is in protected areas. Protected areas include Upper Niger National Park in Guinea, Dulombi-Boe National Park in Guinea-Bissau, Outamba-Kilimi National Park in Sierra Leone, Mont Sangbé National Park in Ivory Coast, Bui National Park and Digya National Park in Ghana, and Old Oyo National Park and Gashaka-Gumti National Park in Nigeria.

Research and Monitoring

Scientists and researchers are actively studying this region to better understand its ecological dynamics, species distribution, and responses to environmental changes. Some key aspects of this research and monitoring initiative includes: