In Guinea, there are six main types of terrestrial ecosystems, which are:

• dense humid forest ecosystems;
• dense dry forest ecosystems;
• Sudano-Guinean savannah ecosystems;
• mountain ecosystems;
• agricultural ecosystems;
• island ecosystems;
• forest plantations.

Dense humid forest ecosystems

They are located in south-east Guinea and are of the Liberian-Ivorian type. Once covering 14 million hectares, they are now only 700,000 ha (Guillard 1989) spread over the Prefectures of Guéckédou, Lola, Macenta, Macenta, N'zérékoré and Yomou.

These ecosystems have experienced a marked decline in recent years as a result of bushfires, extensive livestock farming, uncontrolled logging, artisanal and industrial mining and cultural clearings. They are currently in a very fragmented state.

The plant species characteristic of these types of ecosystem are: Picnantus angolensis, Piptadenia africana, Alstonia congolensis, Antiaris spp, Khaya grandifolia etc.

Dense dry forest ecosystems

They cover the northern half of Guinea except for the central Fouta-Djallon plateau. These forests are crisscrossed by bushfires almost annually. They cover about 800,000 ha with beautiful populations in Mafou, N'Dama, Kissidougou and in the extreme north of Macenta.

The most characteristic species of these forests are: Melicia excelsa, Antiaris africana, Antiaris africana, Khaya senegalensis, Afzelia africana, Sterculia tragacanta, Cola cordifolia, Daniellia oliverii, Daniellia oliverii, Parkia biglobosa, Parkia biglobosa, Pterocarpus erinaceus, Terminalia spp, Combretum spp etc.

These ecosystems contain a rich and varied fauna, the most encountered species of which are: Harnessed Guib (Tragelaphus scriptus), Potamocherus porcus, Lion (Panthera leo), Lion (Panthera leo), Guinea baboon, Guinea baboon (Papio papio), Sitatunga (Tragelaphus s).

The ecosystems of the Sudano-Guinean savannas

They cover most of the national territory and are subject to bush fires every dry season. They are subdivided according to the state of the tree stratum into wooded savannah, tree savannah, shrub savannah, and grassy savannah.

• Wooded savannah: it is characterized by the presence of trees and shrubs forming an open afforestation. This type is found almost everywhere in Guinea and particularly in Upper Guinea with the following characteristic species: Isoberlinia doka, Cacia sieberiana, Parkia biglobosa and Daniellia oliverii.
• Wooded savannah: it is characterized by the presence of scattered trees and shrubs. This type is encountered on plateaus and hill slopes. Species such as Pterocarpus erynaceus, Erythrophleum guineense, Parkia biglobosa, Cuissonia angolensis are characteristic of this type of vegetation.
• Shrub savannah: it is distinguished by the presence of shrubs and a continuous herbaceous carpet and the absence of trees. We especially notice Hymenocardia acida, Andropogon gayanus. This type of savannah is found especially in Foutah Djallon.
• The grassy savannah: it is characterized by the absence of trees and shrubs. This type of vegetation is mainly located in the bowé, which is covered in rainy seasons by Poacae and Pennisetum. This savannah occupies considerable areas in the Prefectures of Boké, Gaoual, Tougué, Koundara, Lélouma and Koubia.

Mountain ecosystems

Middle Guinea and Forest Guinea are the two mainly mountainous natural regions with heights varying between 500 and 1752 m. These ecosystems are important reservoirs of water and Middle Guinea is rightly considered to be the “water tower” of West Africa.

Agricultural ecosystems

They are made up of a mosaic of types of environments reserved for agriculture and livestock in all ecosystems. These areas are occupied on a permanent or temporary basis. There are intensive production systems in the country in which the excessive use of fertilizers is a source of pollution. Moreover, following certain agricultural activities, the accidental and/or intentional introduction of foreign plant species constitutes a threat to local varieties.

Island ecosystems

Guinea has very few islands. The main ones are: Alcatraz Island, Shipwreck Island, Shipwreck Island, Tristao Islands, Tristao Islands, Loos Islands (Kassa, Tamara, Room, Korail and Banche), Moteba Island (Rio Pongo).

Forest plantations

Some were carried out during the colonial period and others during the various economic development plans of Guinea from 1963 to 1979.

Other plantations were continued until 1994. These plantations are found almost everywhere in the country and particularly in Middle Guinea and Forest Guinea. These include:

• pine plantations from Sebhory to Dalaba,
• from Gmélina and from Teck to Kindia
• From Teck to Gaoual, to Bérékéna to Kankan and to Pensély in Mamou

from Terminalia sp to Ziama in Macenta.