Cameroon: Trees, water, soil and endangered wildlife
Mount Bamboutos is part of the 'Western Cameroon Highlands volcanic line. It is north of the Equator at the border region between Nigeria and Cameroon. It is an area of global biodiversity importance that includes the endangered Cross River gorilla.
Though today a highly productive landscape for its people (with the use of external nutrients through fertilizers and even pesticides), what will Mount Bamboutos be like in 10 or 20 years under the current trend of increasing population, farming and forest loss?
The "Mount Bamboutos Initiative" (MBI), a project of the International Tree Foundation (ITF) with the Environment and Rural Development Foundation (ERuDeF), aims to support a more sustainable path in Mount Bamboutos over the next 15 years through reforestation. It will connect altogether community forests, riparian forests, sacred forests, protected areas, and agroforestry systems.
The area holds the possibility to plant 3 million trees across 150km(2) or the size of Denver airport in Colorado (USA), under the following land use categories:
Community Forests (1) and sacred forests (33% of the total project area). It represents the potential for planting 1,300,000 trees.
The land was proposed as an 'IUCN category 4-6 Biodiversity reserve' (40%). It represents the potential for planting 600,000 trees.
Riparian areas forests (outside those inside Community Forests and the reserve) (4%). It represents the potential for planting 300,000 trees.
Private small lands (23%). It represents the potential for planting 800,000 trees.
Treesisters has been partnering with ITF on MBI since 1st April 2018 in the southwest portion of Mount Bamboutos. The partnership aims to plant 600,000 trees over three years and 3,000 hectares ( equivalent to 4,000 soccer fields). The project will involve and benefit 1,000 households drawn from 3 villages.
Geography
Mount Bamboutos is a volcanic massif located in western Cameroon. It is a very rugged and varied landscape with several high peaks, steep slopes and deep valleys. One of its peaks is the 3rd highest in Cameroon, jutting up to 2,740 meters. An extinct caldera of sub-elliptical shape (16x8 km) sits at the heart of the massif, with rock blocks covering its floor.
Mount Bamboutos massif spans three administrative regions of Cameroon (southwest, west and northwest), five divisions (Bamboutos, Menoua, Mezam, Momo and Lebialem) and eight subdivisions. It is mainly inhabited by the Bamileke tribe. Southwest and northwest are primarily English-speaking, and western Bamboutos are primarily French-speaking.
(Photo: Mount Bamboutos mountain tooth ©ERuDeF.)
Mount Bamboutos include tropical wet montane forests above 1,700m of altitude, also called cloud forests, as well as tropical sub-montane forests in the lower slopes of the mountain range from 1,100 to 1,750 meters.
Climate and Soil
It is a place of high annual rainfall (2,000 to 3,000 mm) and humidity. The climate is characterised by the alternation between a wet and a dry season of variable intensity. At Dschang, a city at 1,380m high, the temperature is mild throughout the year with an average temperature of 18.9°C, with the highest monthly mean of 23.4°C between March and April and the lowest (14.3°C) in December (2).
Mount Bamboutos' forests sit on soils with andic characteristics (3), which means they hold considerable soil fertility but great vulnerability to land degradation. Tree removal and today's agricultural approach are certainly not the most appropriate. Heavy rainfall and steep slopes lead to significant soil erosion and landslides.
Photo by EruDef, Regent Chief of Formenji, pointing at the degraded community forest in Formenji Bamumbu to be restored.
History of the Mount Bamboutos forests
A map of Mount Bamboutos' massif created in 1957 by the French Geographic Institute (IGN) (4) shows that land cover at the highest altitudes included primarily tree and shrubby savannas, as well as grasslands. Forests were only found in the valleys and along streams as forest galleries and on very steep slopes. On the flat elevations, trees were associated with horticulture and crops, surrounded by grasslands/pasturelands and steppes for livestock grazing.
In the 1970s, the populations living in the densely populated piedmont (5), a gentle slope leading from the base of the mountain to a flat land region, suffered from declining crop yields and a lack of jobs. They started to expand upwards. Settlers found the necessary water, cool temperature, and highly fertile volcanic soils to grow marketable vegetables there. More people means firewood harvesting, livestock grazing, and more shifting cultivation and agriculture lands.
Consequently, today, the massif's piedmont and slopes support a polyculture of coffee and food crops (6) and are a densely populated area. 4,000 people settled inside the caldera to grow potatoes, cabbages, leeks, carrots and maize (7). Farmers of the southern flank of Mount Bamboutos raise pigs, goats and hens.
In the northwestern and western portions of the mountain, forests are much degraded and mostly found in deep valleys and along streams (8). Only southwest of Mount Bamboutos, where TreeSisters is involved, remains the most forested portion of Mount Bamboutos.
The caldera floor is quite deforested, and that was probably true even in the 1980s, as shown by a study that assessed forest loss by 5.8% between 1980 and 2016 (9).
The very small 'Mount Bamboutos Forest Reserve' of just 215 hectares created in 1900 by the Germans ‒reconfirmed successively by the French in 1947 and by the Government of Cameroon in 1972, has since been wiped out. In 1957, the forest no longer existed in reserve; it was already covered in trees and shrubby savannas, as shown by the map created by IGN.
Trees still form parts of the farming systems at the piedmont, but this is not the case on the horticulture farms located up the mountain where space is limited. Historically, the upper parts of the mountain have been used for grazing by the pastoralist community. Additionally, horticulture requires irrigation and can only take place near a stream.
The forests of Mount Bamboutos have also suffered from overexploitation. African stinkwood (Prunus Africanus) was completely decimated by the early 1990s due to overexploitation by the French pharmaceutical company Plantecam Medicam and the local people for its bark, known to treat prostate cancer in men.
Land cover/land use change in the MBI project area. Map produced by ERuDeF.
Note: CTE refers to the large private commercial tea plantation. Sparse vegetation refers to the remaining areas of partial forest cover.
Plant, Tree Variety and Wildlife
In spite of the catastrophic loss of montane forest and loss of exclusive birds ‒as it was described as the richest biodiversity hotspot for birds in all of west and central Africa, Mount Bamboutos still harbours incredible biodiversity, especially in its southwestern portion where TreeSisters is involved. This is no longer true for the slopes of the mountain in West and Northwest Mount Bamboutos.
Mount Bamboutos forms part of the Cameroon Highlands ecoregion (10), one of the world's 200 ecoregions of primary importance. A survey conducted in 2010/2011 found that 100 plant species belonging to 82 genera were identified at sub-montane and montane altitudes, with the genera Cola and Psychotria being the most represented (11). Some plant species are under the IUCN's Red List, such as Ternstroemia spp and Allanblackia gabonensis.
Southwest of Mount Bamboutos still harbours a high diversity of mammals, including the endangered forest elephant, the endangered Preuss' guenon (Cercopithecus preussi), the critically endangered Cross River gorilla (Gorilla gorilla diehli), and the most endangered Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti).
Only 300 individuals of Cross River Gorillas remain in the wild, scattered across 11 isolated, tiny remaining sub-populations found in the remaining montane forests. Unable to adapt and cope with diseases and vulnerable to inbreeding, their reproduction is difficult. They are labelled as critically endangered (12). Three protected areas were created in the past ten years for the conservation of Cross River Gorilla, within which one sits in our project area, namely the Tofala Hill Wildlife Sanctuary.
Mount Bamboutos still harbours today birds that are endemic to Cameroon such as the Bannerman's Turaco (Tauraco bannermani), which is critically endangered, the endangered Banded Wattle-eye or Bamenda Pririt (Platysteira laticindra), which is only known in Mount Bamboutos and nowhere else on Earth. But for how long in small isolated fragments of the forest below unsustainable population levels?
Water Catchment
Mount Bamboutos is the 2nd most important water tower in the country, but it is already losing its function as a water catchment. Streams dry up in the dry season (13). Horticulturalists need to tap into streams to irrigate their crops in the dry season. Due to ever-shrinking forest cover, the watershed does not recharge sufficiently during the rainy season.
Water extraction is having an impact on 81,257 people living downstream (14). It puts at risk the functioning of the country's two major hydroelectric plants fed by streams generated by the Mount Bamboutos water catchment. Moreover, communities are fighting, and pastoralists are blaming the horticulturalists.
One of the big problems is that irrigated horticulture is being practised on the mountain's upper slopes, so water extraction is taking place at the very top of the catchments. And that is often where the springs emerge.
"It seems that what has been most important was to build pipes for water distribution, but no one had ever thought before of where that water was coming from ..." - Louis Nkembi, ERuDeF's CEO.
Soils
Without tree cover, soils dry out fast during the dry season. Cultivated soils on the slopes are exposed to erosion. Frequent hazards of meteorological origin coupled with the geological and geographical context of the mountain ranges do cause landslides, and rock falls (11). This is exacerbated by bushfires set up by local people and deforestation.
Population and Health Risks
Today, high yields in horticulture are supported by costly and polluting external chemical inputs. Community members use significant quantities of agricultural chemicals on horticultural crops. Fungicides are applied on potatoes using knapsack sprayers, with little or no personal protection. Chemicals are sprayed right at the top of the catchments, causing water pollution downwards. There is a widespread concern amongst the community about the potential health risks resulting from the contamination of water sources with chemicals. There are reports of high cancer rates