Mount Oku, or Kilum Mountain, is the largest volcano in the Oku Massif, in the Cameroon Volcanic Line, located in the Oku

Oku

Oku is Sub Division in the Northwest Cameroon. The term Oku also refers to the people who live in this region and the primary language that they speak . Oku is a rural area containing about thirty-six villages...

 region of the Western High Plateau

Western High Plateau

The Western High Plateau, Western Highlands, or Bamenda Grassfields is a region of Cameroon characterised by high relief, cool temperatures, heavy rainfall, and savanna vegetation. The region lies along the Cameroon line and consists of mountain ranges and volcanoes made of crystalline and igneous...

 of Cameroon

Cameroon

Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...

.
It is the second highest mountain in mainland West Africa

West Africa

West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...

.
The stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 rises to 3,011 m above sea level, and is cut by a large caldera

Caldera

A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

.

Geology

Some of the rocks have ages starting from 24.9 to 22.1 million years ago, but much more recent activity has occurred.
The mountain is built of basaltic and hawaiitic lavas, succeeded by trachytes

Trachytes

Trachytes is a genus of mites in the family Trachytidae.-Species:* Trachytes adrianaea Hutu, 2000 * Trachytes aegrota * Trachytes aegrotasimilis Hutu, 2001 * Trachytes aokii Hiramatsu, 1979...

, and then by large volumes of trachytic and rhyolitic ignimbrite

Ignimbrite

An ignimbrite is the deposit of a pyroclastic density current, or pyroclastic flow, a hot suspension of particles and gases that flows rapidly from a volcano, driven by a greater density than the surrounding atmosphere....

s with a thickness of up to 1,000 m.
Further trachytic lavas, tuff

Tuff

Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...

s and breccia

Breccia

Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....

s were produced, and the most recent phase produced pyroclastic cones and explosion craters.
One of these craters holds Lake Oku

Lake Oku

Lake Oku is a crater lake on the Bamenda Plateau in the Northwest Region of Cameroon. It is located at on Mount Oku, and is completely surrounded by cloud forest....

, from which flows of basalt issued in the north, and of rhyolitic and phonolitic lavas in the south.

Ecology

A small sphagnum

Sphagnum

Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...

 community with associated wetland plant species was discovered at 2,900 m in 1997, near the summit of the volcano, the highest sphagnum bog in West Africa. This site includes several plant species endemic to the Kilum-Ijim area, and is of extremely high conservation importance.
The 200 km² of forests of the Kilum-Ijim area around the mountain form the largest remaining patch of montane forest in West Africa

West Africa

West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...

, an important habitat for endemic species of animals and plants.
The forest is at risk, since it is surrounded by a high density of human settlements.
BirdLife International

BirdLife International

BirdLife International is a global Partnership of conservation organisations that strives to conserve birds, their habitats and global biodiversity, working with people towards sustainability in the use of natural resources...

and the Ministry of the Environment and Forestry are jointly operating the Kilum-Ijim Forest Project, which aims to conserve the forest biome, maintain biodiversity and ensure sustainable reuse.

Most of the area within the Kilum-Ijim boundary is above 2000 metres in height, and consists of montane forest mixed with montane grassland and subalpine communities. At lower elevations, most of the submontane forest has been cleared for agriculture. Based on satellite images, between 1958 and 1988 about half of the forest was lost, although regeneration began soon after the conservation project was started in 1987. Since then there has been steady recovery of the forest reserve, which is under the direct management of the Kilum-Ijim communities.