Oheneba Poku Foundation is in partnership with the Asantehene Otumfuo Osei Tutu ll to undertake the landscape restoration of the lake Bosomtwe which has been declared a biosphere by The United Nations Educational, Scientific and Cultural Organization (UNESCO). The project seeks to plant 2.5million trees and enforce conservation agricultural practices throughout the Bosomtwe Biosphere enclave amongst all farmers.
We believe that adopting the no-till practice will improve tree cover around the lake as a means of restoring ecosystem integrity, improving biodiversity and enhancing ecosystem service provision such as carbon sequestration, prevention of soil erosion, and protection of watersheds.
About Lake Bosomtwe
Lake Bosomtwe is the only natural lake in Ghana. It is situated within an ancient impact crater that is about 10.5 kilometres in diameter. It is about 30 km south-east of Kumasi the capital of Ashanti and is a popular recreational area. There are about 30 villages near crater lake Lake Bosomtwi, with a combined population of about 110,000 people.
Lake Bosomtwe is an important national, cultural and natural site of relevance for international conservation. The lake catchment spans two districts, Bosomtwe and Bosome-Freho, and consists of a mixture of three unique types of ecosystems – forests, wetlands and mountains – which contribute to the conservation of vital biodiversity.
Lake Bosomtwe, Ghana’s only natural lake, has been designated a biosphere reserve site by the United Nations Educational, Scientific and Cultural Organization (UNESCO) to promote healthy balance between biodiversity conservation and its sustainable use.
A tripartite agreement has been signed between UNESCO; the Ministry of Water Resources, Works and Housing of the Republic of Ghana; and Otumfuo Osei Tutu II, Asantehene, the Custodian of Lake Bosomtwe to implement a sustainable management plan for the entire Lake Bosomtwe Biosphere Reserve.
Latitude: 6°24’35”N – 6°35’33”N
Longitude: 1°19’22”W – 1°29’30”W
Midpoint: 6°30’16”N – 1°24’31”W
Surface area (terrestrial and marine): 28,699 ha
Core area(s): 1,159 ha
Buffer zone(s): 10,741.5 ha
Transition area(s): 16,798.5 ha
The paradigm for ecological design within the Lake Bosomtwe biosphere will help create a system that is
- Ecologically functional
- Naturally maintainable
- Environmentally sound
- Visually pleasing
Riparian buffer strip restoration
A riparian buffer strip will be maintained along the sides of the lake to protect the shoreline and water quality from agricultural runoff. Wider vegetative strips are more effective than narrow ones at reducing flood impact and slowing stream bank erosion so a buffer strip of not less than 50 meters will be created. It is expected that in the long term, there will be no human interference within the buffer strip. However, during the early years, two human induced activities will be carried out through the Community Managed Natural Regeneration (CMNR) processes.
These activities are
1. Enrichment planting
2. Full re-vegetation
This will be done in areas that have a fair amount of the natural vegetation still in existence. Community members will be trained on the processes of natural resource regeneration. Existing tree species, shrubs, vines etc. will be managed to ensure that they enjoy the best conditions to grow. Empty spots will be planted with trees, shrubs and other species that will enhance the build-up of an ecological niche resemblance of the existing ecology.
Thus, as we design and implement fresh patterns on the landscape, we augment what is already there and implement an integral and sound ecology within the biosphere.
There are areas within the biosphere that have been more seriously degraded with very little or no vegetation. Such areas requires complete re- vegetation bearing in mind the requisite plant species to ensure adequate ground and above ground cover within the shortest possible time.
In order to ensure community commitment and active participation in the above activities, a biannual ecological stewardship assessment will be conducted within the biosphere and the best five communities rewarded at a biannual Lake Bosomtwe Ecology Day. This will create some sort of competition among the 23 communities which in turn will help to accelerate the creation of ecological sanity within the entire biosphere.
In addition to fishing in the Lake, crop farming is a major livelihood activity of people living around the Lake. Clean field land preparation resulting from slashing and burning as well as loosening the soil with the hoe continue to
be the major land preparation practice for farmers in the area. These methods of land preparation predispose the soil to erosion with huge volumes of soil moving down into the Lake.
The high intensity of siltation has the potential of reducing the effective surface area and depth of the Lake thus continuously reducing the water volume in the Lake. The other side of the problem is the pollution of the Lake resulting from extensive use of agro-chemicals by people farming uphill.
A reversal of the above situation with a consequent positive effect on the Bosomtwe biosphere is what we urgently need. This can to a greater extent, be attained through the adoption of environmentally friendly and sustainable agricultural production systems such as one can find in Conservation Agriculture (CA). CA systems are those that utilize soils and crops with the aim of reducing mixing-up of the soil and maintaining the crop residues on the surface in order to minimize damage to the environment. CA is based on certain principles notably,
- Minimal soil disturbance over the long term
- Maintaining permanent organic cover by leaving the previous year’s residue on the field and the integration of cover crops
- Crop diversification through rotation and/or intercropping to improve soil fertility and to control pests and diseases
- Increased profits, in some cases from the first year and in all cases after a few years
Oheneba Poku Foundation seeks to train farmers in all the 23 communities around the Lake in conservation agriculture. This will be followed up with the establishment of one learning plot in each community where farmers
will have hands-on experience to be transferred to their individual fields.
Where appropriate and more especially on the slopes, contours will be delineated and stabilized with living barriers especially using lemon grass which will have an economic value in addition to reducing soil and water movement down the slope. The emphasis will be on conservation agriculture with trees where every farmer will be required to maintain a certain number of trees per unit area without undue disadvantage to the commercial or food crops.