Gabon is located on the Atlantic coast of Central Africa, on the equator and shares its borders with the Gulf of Guinea, Equatorial Guinea, Cameroon and the . The Crystal Mountains National Park is located between the Provinces of Estuaire and the Woleu-Ntem. Crystal Mountains National Park is a twin park and one of Gabon's 13 national parks. It lies in the Monts de Crystal on the western edge of the Woleu-Ntem Plateau between Equatorial Guinea and the Ogoou River. The twin parks Mbe National Park and Mt Sene National Park were established on September 4, 2002 for their exceptionally high plant diversity and are part of a former Pleistocene rainforest retreat.

The park is home to many species of animals such as elephants or monkeys and hundreds of species of butterflies, some of which are very rare such as Euphaedra brevis, Cymothoe or Graphium Angrier can be found here. Part of the area is preserved in Gabon as the Crystal Mountains National Park. Mont Mbilan is the highest point about 925meters in the park. Seni Mont 611meters receives the highest rainfall in all of Gabon (350 cm/year)

Ten villages are located around the Crystal Mountains National Park, with a total population of 1100 inhabitants and relatively low human density of 2 inhabitants. This Park is covered by dense forest and includes some of the highest areas of Gabon, with summits above 900 m above sea level. The botanical diversity is one of the richest of Africa, with numerous endemics. The Crystal Mountains harbour a rich mid-altitude herpetofauna, including regional endemics. The area was classified as a National Park in 2002 due to its global conservation importance, shortly after the World Summit on Sustainable Development held in Johannesburg, South Africa. The area was also classified by Central African Regional Program for the Environment as one of twelve priority landscapes for monitoring biodiversity, deforestation and other disturbances.

Vegetation

The dominant vegetation is terra firma forest of which 15-18%, in Gabon at least, has been modified by agriculture. Near the estuaries of the Rio Muni and the Komo, there are stretches of swamp forest. The dominant tree families are Burseraceae, Euphorbiaceae and Leguminosae-Caesalpinioideae. Above 650 meters, the forest formations show submontane influences and, on high peaks or slopes exposed to the clouds of the Atlantic, there are cloud forests recognizable by their abundant epiphytes.

The inselbergs also have very particular vegetation, with meadows of Afrotrilepis pilosa and thickets very rich in epiphytes. , there are some species with a very limited distribution, particularly Bikinia durandii, a Caesalpinioideae, and Marquesia excelsa, the only Dipterocarpaceae in Africa, which is endemic to Gabon. Crystal Mountains constitute the richest forest formations in Central Africa, from the point of view of both alpha and beta diversity, and the second richest in the world following a site in Ecuador.

Biodiversity

This area is characterized by complex biodiversity: it is a home to 8,000 plant species, almost 200 mammal species and 600 bird species. This endemic richness in flora and fauna places the country in the top forest complexes in Africa. The mean minimum and maximum annual temperatures are 23ºc and 26ºc and the mean annual rainfall is 3, 500 mm in the northern part of the National Park and 2000 mm in the eastern part of the NP. The climate ranges from tropical to humid. Subsistence farming, fishing and hunting is most practiced around the park.

The products mainly cultivated are plantain, cassava (these are done at a subsistence level) and cacao, coffee, palm nuts, sugar cane, different types of fish. In addition, the community makes use of fuel wood as a source of energy and cooking. A watershed is situated in the National Park, and is a center of tourist attraction. The area was considered small enough and accessible for the study, data gathered can be interpreted evocatively and possibly used for further studies in national parks or at a larger scale. Hunting for bush meat represents the main threat to biodiversity.

Landscape

The Landscape occupies a rugged area of plateaus and mountain chains mainly situated at an altitude of 300 meters to 650 meters to the northeast of the coastal sedimentary basin of . The relief forms alignments running from the northeast to the southwest. The highest point is Mont Mbilan 800 meters. The vast majority of rocks in the Landscape are Archean. In Gabon, the 3.2 billion years old non-differentiated gneisses are dominant, but there are also formations of amphibolites, aged 2.9 to 3.2 billion years, and ultramafic intrusions, 2.7 to 2.8 billion years old. The Landscape is drained by four watercourses that fl ow towards the southeast. The Mbé and the Komo form part of the basin of the Gabon Estuary. The Adouré and the Noya turn west and then northwest before ending in the Muni Estuary.

Climate

Across the Landscape, annual rainfall varies between 2,000 milimeters in the east to 2,800 milimeters in the west. There is a dry season of three months that runs from July to September, but its effects are considerably attenuated by the fact that a good part of the Landscape is then shrouded in low clouds. Not only does the whole region have high rainfall, but the humid winds from the Atlantic and the clouds that drift into the western flank of the mountains maintain a high level of humidity, especially in the dry season when the clouds are very low. These special conditions existed during the glacial eras. They were perhaps even more marked at that time due to the fact that the surface temperatures in the Gulf of Guinea were lower and stratiform clouds were more frequent. The mountains in this Landscape have thus been able to maintain large forest formations and represent a forest refuge.

Wildlife

The forests in the park contains most of the mammals typically found in the forests of western Central Africa, notably the forest elephant, the buffalo, the giant pangolin, the water chevrotain, six species of duiker, the lowland gorilla, the chimpanzee, the mandrill, the black colobus, the Ogooué talapoin monkey, the leopard and the golden cat. The aardvark has also been reported. In the lower parts of Equatorial Guinea, the white-collared mangabey and the hippopotamus have been found. It is important to mention that on the fringe of the Landscape but still within the same forest block manatees live in the Komo river and Abanga river.

The park is home to an estimated 48 reptile species. The reptiles are still poorly known, but their fauna appears rich and representative of the forests of the region. It includes the forest crocodile, the false gavial, the forest tortoise, the ornate monitor and the African python. In the crystal mountains national park, 48 species have been counted so far, but the total number of species is probably around 65. Amphibians species have been found that are associated with forest waterfalls; several of these species were only known from western Cameroon and one is a new species for science.