ENVIRONMENT






 




















 




The rainforests of West Africa have been earmarked as one of the world's hotspots for biodiversity. These forests extend from Senegal to Togo, and are referred to as the Upper Guinean forests. These are separated from the rest of the African rainforests by the Dahomey gap: an extension of the woodland savanna from the Sahel to the Gulf of Guinea. As a result of its isolated position, the Upper Guinea forest zone harbours a large number of endemic animal and plant species. Tacugama's 100 acres of protected area boasts a plethora of wildlife and plant biodiversity. Walking around the sanctuary you can very easily stumble upon hundreds of rare species of plants and animals.

Environment

Sierra Leone is located on the Atlantic coast of West Africa, and lies at the western end of the upper Guinean Forest Block. It is one of the most severely deforested countries in the region. At the beginning of the century about 70% of Sierra Leone was covered by mature closed forest, but by 1976 this number had been reduced to 5%. Another 3.5% was under secondary forest.

Logging, mineral exploitation and slash-and-burn agriculture have all taken a toll on the country’s rich biodiversity (biological life). With nearly 28 categories of protected areas in representative ecosystems, the total mature forest coverage is still less than 4% of the land area, with nearly all of these protected regions suffering from inadequate protection due to lack of manpower, technical support and financial resources. Sierra Leone has also gone through a costly civil unrest, with severe impact on its human life and biodiversity. The most important remaining forest areas are the highlands of the southern and eastern provinces, and on the axial mountain chain of the Western Area Forest (WAF).

  
Map of Africa with the distribution of the tropical rain forest in West and Central Africa 

Western Area Forest Reserve

The Western Area Forest covers the hills of the Freetown Peninsula and is the westernmost area of closed-canopy forest remaining in Sierra Leone. It is separated by about 160 km from the nearest area of the closed canopy forest at Bo.
In order to conserve the forest, soil and water the first part of the Western Area Forest Reserve was designated in 1916. Subsequent additions between 1916 and 1973 have brought the total area of protected land to 17482 ha. Since the Wildlife Conservation Act 1972, the area has been designated a non-hunting forest reserve. However, as shown in the figure, the area is steadily shrinking due to increased pressures from human encroachment. In 2014 the forest reserve was upgraded to a national park, and is now called; Western Area Peninsula National Park.

The whole area lies under Western Area administration, while the responsibility for the Forest Reserve lies with the Forestry Division of the Ministry of Agriculture, Forestry and Food Security. Land in Western Area outside the National Park is privately owned, in contrast to the situation elsewhere in Sierra Leone, where most areas outside reserves are under chiefdom control.

Furthermore UNESCO has accepted the Western Area Peninsula National Park's application as tentative site as UNESCO World Heritage together with Tiwai Island and Gola Forest National Park.

Vegetation

Most of the Western Area Forest is classified as Guineo-Congolian rainforest of the hygrophilous coastal evergreen type. It has a closed canopy at about 30m with emergent trees rising above this canopy. The drier rocky slopes and summits support low scrub forest. The laterite pans are covered by natural grassland, since the soil there is too poor to support scrub or high forest. As a result of past human activities very little of the original rainforest remains in an undisturbed state.

The areas inland of the Peninsula are a mixture of farmbush and scattered grassland with small remnants of Lophira savannah. Neighbouring coastal areas support mangroves. Tacugama Forest Reserve was covered with primary and/or mature forests in the past. However, most of this area is now covered with secondary forest and farm bush, as a result of heavy deforestation by and shifting cultivation, charcoal burning and lumber extraction for building. More than 100 different species of birds have been identified in and around the Tacugama Forest Reserve.

More than 2000 species of plants occur in Sierra Leone, of which about 74 species and one genus are endemic.


Wildlife



614 bird species have been recorded in Sierra Leone, of which six are threatened. The white-breasted guinea fowl (Agelastesmeleagrides) was recently rediscovered in Sierra Leone and is considered as one of the most threatened birds in continental Africa.

There are 15 species of primates in the country, of which 11 are forest species. Six of the pimate species are considered threatened. These include the western Chimpanzee (Pantroglodytes verus), the Black and White Colobus Monkey (Procolobuspolykomus), the Red Colobus Monkey (Colobusbadiuspolykomos), the Diana Monkey (Cercopithecusdiana),  and the Olive Colobus Monkey.  

There are 18 species of antelopes, of which 9 species are threatened and 16 endangered. These include the Jentink (Cephalophusjentinki) and Zebra duikers (Cephalophus zebra). Other threatened mammal species include one species of forest elephants (Loxodontaafricanacyclotis), which is believed to have almost gone extinct, the West African Manatee (Trichechussenegalensis), the pigmy hippopotamus (Hexaprotodonliberiensis) and the leopard (Panterapardus).

There are 9 species of fruit bats and 3 species of crocodiles (Nile, Slender-snouted, and Dwarf). There are 130 species of fresh water fish, 108 species of butterflies and 5 species of marine turtles.

Relatively few endemic invertebrates are known to exist and these include two dragonfly species, (Argiagrionleoninum and Allohizuchacampioni), the rare giant swallow-tail butterfly, (Papilioantimachus), which reaches its western limit in Sierra Leone.

Most of the wildlife populations have been severely depleted outside of protected areas as a result of over-hunting and habitat destruction.

Fauna of the Lowland Rainforest Ecosystem of Sierra Leone:

  • Jentink's duiker (Cephalophus jentinki)
  • Zebra duiker (Cephalophus zebra)
  • Pygmy hippopotamus (Hexaprotodon liberiensis)
  • Royal antelope (Neotragus pygmaeus)
  • Black duiker (Cephalophus niger)
  • Ogilbys duiker (Cephalophus ogilbyi brookei)

Fauna of the Montane ecosystems:

  • Maxwells duiker (cephalophus maxwelli)
  • Hippopotamus (Hyemoschus aquaticus)
Fauna of the Savanna Ecosystem:
  • Aardvark (Orycteropus afer)
  • Western dassie (Procavia capensis)
  • Common hippopotamus (hippopotamus amphibus amphibus)
  • Red river hog (potamochoerus porcus)
  • Giant forest hog (Hylochoerus meinertzhageni ivoriensis)
  • Warthog (Phacochoerus aethiopicus)
  • Water chevrotain (Hyemoschus aquaticus)
  • Red flanked duiker (Cephalophus rufilatus)
  • Blue duiker (cephalophus monticola)
  • Yellow backed duiker (cephalophus sylvicultor)
  • Bushbuck (tragelaphus scriptus)
  • Waterbuck (Kobus ellipsiprymnus defassa)
  • Forest buffalo (Syncerus caffer)
  • African elephant (Loxodonta cyclotis africana)
  • Cape clawless otter (Aonyx capensis)
  • Spotted neck otter (Lutra maculicollis)
  • Ratel (Mellivora capensis)
  • African civet (Viverra civetta)
  • Palm civet (Nandinia binotata)
  • Genet (Genetta spp)
  • Dwarf mongoose (Helogale parvula)
  • Marsh mongoose (Herpestes paludinosus)
  • Egyptian mongoose (Herpestes ichneumon)
  • Cusimanse mongoose (Crossarchus obscurus)
  • Serval (Leptailurus serval)
  • African wild cat (Felis sylvestris)
  • Leopard (Panthera pardus)

Fauna of the Wetland ecosystem:

  • West african manatee (Trichechus senegalensis)

Climate

The climate is tropical with relatively constant temperatures. The maximum and minimum temperatures varying between 30 °C and 25 °C in April, and 27 °C and 23 °C in August.

The rainy season lasts from May to October, over half of the rain falling in July and August. Average annual rainfall varies between 3000 mm on the inland side of the Peninsula and 6000mm on the western side, with up to 7000 mm falling on some of the peaks.

Between December and February the cool, dry Harmattan wind sometimes blows from the north, reducing visibility.

Humidity is high. Relative humidity at 15:00 hours varies between 69% in January and February to 82% in August.