3.1. In situ conservation activities
3.2. Ex situ conservation activities
3.3. Selection and genetic improvement
3.4. National priority species
Protected areas and sacred forests
Forest genetic resources of this region are traditionally protected and conserved on farm lands within the scattered agroforestry enclaves of the people. The total land area under forest reserve for the region is put at 342, 158 Km². While the Sahel savanna covers an area of 31,468 Km² (CFAD, 1979). Within the region some of the species are protected in parks and fetish grooves arising from mythological reasons, which forbids the cutting of some species such as Adansonia digitata and Tamarindus indica, Acacia senegal and Faidherbia albida. In the central part of this region (Kano) there is Falgore Game Reserve, which harbours many of these trees including Isoberlinia doka, Khaya senegalensis, Vitex doniana, Anogeissus leiocarpus, Tamarindus indica, Detarium microcarpum and Pterocarpus erinaceus.
Table 2: Distribution pattern of threats to forest trees in the sub-Saharan zones
Ecological zone |
Item |
Percentage representation (%) |
Zone A (Zaria) southern. Guinea savanna zone
|
Illegal felling |
45-65 |
Demographic |
10-15 |
|
Industrial |
5 |
|
Plantation forestry |
15-20 |
|
Drought |
10-20 |
|
Others (insects) |
< 5 |
|
Northern Sudan zoneZone B (Kano-Jigawa) central.
|
Demographic |
10-15 |
lndustrial |
15-20 |
|
Plantation forestry |
25-35 |
|
Zone C (Sokoto-Bornu) Northern. Semi arid region. |
Illegal felling |
40-55 |
Drought |
10 |
|
Others (insects) |
<2 |
|
Demographic |
2-5 |
|
lndustrial |
5-10 |
|
Plantation forestry |
20-35 |
|
Illegal felling |
35-45 |
|
Drought |
20-35 |
|
Others (insects) |
>3 |
Table 3: Areas of forest reserves as at 1983
State |
Total land area (km²) |
Area of reserve (km²) |
% of Reserve forest to land area |
Kaduna (now Kaduna and Katsina) |
69,392.85 |
8,825.19 |
12.72 |
Kano |
43,743.94 |
1,979.79 |
4.52 |
Sokoto |
91,960.06 |
20,358.21 |
22.17 |
Borno |
199,132.17 |
1,823.50 |
4.00 |
Source: Onochie 1983Traditional agroforestry parklands systems
Most commonly observed agroforestry systems involve near pure stands of some of the following species especially Parkia sp. and Vitellaria sp. in south-central zone and Tamarindus-Anogeissus-Parkia in the northern zone. Most of these were derived from remnants of long time protective land use and manipulations of elements of the original vegetation in favour of the indigenous multipurpose trees in the farming systems.
Forest enrichment or plantation
Strict natural reserves or plantations for any of the indigenous tree species are rare across the region. However stands of these indigenous trees may be found within some of these plantations.
Seed banks
Most afforestation projects in the region are dominated by exotic species and seed supply and demand can be considered as relatively adequate. However seed supply for most of the indigenous tree species are grossly inadequate due to poorly managed seed orchards, intensive collections and utilization by farmers and in-adequate facilities for seed collections and storage by both the state and national forestry organizations. The interest of the farmers to plant indigenous trees is still low due to their slow growth, which had equally affected the replenishment of the old mother tress in the parklands. Most farmers prefer the cultivation of arable food crops to growing of indigenous fruit trees. In addition many of the woody species producing edible fruits are intensively harvested both for food and cash with very little quantity preserved for planting. In almost all parts of the region, supply of seedlings of indigenous woody trees are in limited supply. In recent times, following the report of Nigeria Environmental Study Action Team (NEST, 1990) and the advent of Federal Environmental Protection Agency (FEPA) and National Centre for Genetic Resources Conservation and Biotechnology (NACRAB), the trend is changing. In addition, a number of NGOs are now involved into ex situ and in situ conservation of the forest genetic resources. These organisations include the Nigeria Conservation Foundation (NCF), the Centre for Research and Development in Natural Resources and Environmental Development (CENRAD), and Plant Diversity Research Organization (PDRO).
Some orchards exist in state and federal Department of Forestry and Forestry Research stations in the region along with ex-situ conservation for some of the indigenous trees for seed collections and progeny trials. Species including Parkia biglobosa, Vitellaria paradoxa, Adansonia digitata, Tamarindus indica, Entada africana, Moringa oleifera and Diospyros mespiliformis. Acacia senegal and Acacia nilotica are receiving attention. Periodically, seeds collected are processed and distributed to the seed sections of the Agricultural Development Projects, which maintain direct contact with farmers (stakeholders). The National Agricultural Research Project (NARP, World Bank Assisted) of which the Forestry Research Institute of Nigeria (FRIN) is a part has recently embarked on 1 million seedlings production for afforestation and agroforestry projects and some indigenous trees are included to meet up this region seedlings supply.
Table 4: Seedlings production in the semi-arid region year 1992
State |
Seedlings production in 1992 |
Borno |
649,400 |
Kaduna |
2,078,100 |
Kano |
2,800,000 |
Sokoto |
2,020,000 |
Katsina |
3,478,940 |
Source: The Green light magazine 1992Ex-situ conservation work started for Parkia biglobosa in 1993 and ninety four accessions have been collected and conserved in the seed gene bank in FRIN with fifty four accessions belonging to the rest of West Africa (Sarumi et al., 1995).
The major problem in conservation work has been funding and under-maintenance of storage facilities. Currently the country has two properly equipped seed centres with professional and trained support staff. These centres are the main sources of seed collection, storage and handling for all user groups. More sophisticated equipment are required for seed harvesting, cleaning, handling, processing, sorting, drying and storage. Information documentation is inadequate, old-fashioned, cumbersome and often not standardized. Gene bank management, exploration methodologies and computer skills are also the priorities.
Forest plantation
Except for Acacia senegal commercially exploited for gum arabic with plantations existing in Yobe and Domo states, other plantations are mainly for afforestation and shelterbelts planted up with exotics including Pinus spp, Eucalyptus spp., Gmelina arborea, Azadirachta indica and Senna siamea.
Few trial plots exist for Parkia biglobosa, Vitellaria paradoxa and Tamarindus indica in both the southern (Zaria) and northern (Katsina and Sokoto) zones. The Savanna Forestry Research Station of FRIN established these plots. In the northern zone (Katsina and Sokoto) trial plots are in place for Moringa oleifera, Parkia biglobosa, Acacia nilotica, Tamarindus indica, and Vitex doniana. They were established through the EEC/Katsina state Arid Zone Project. Some form of deliberate plantings exist for a number of these species by both the farmers (seedlings supplied by local and state Forestry Departments) and direct planting by the State Forestry as demonstration plots or woodlots while the local governments have established small afforestation projects and enrichment plantings either as monoculture on the farmers plots or around homesteads. Instances of some of these trees forming a component of avenues along the major roads are also in practice. Most of the forestry sector, pre World Bank assisted NARP Project were not adequately funded by the national government. However, since the onset of NARP, many areas have been cultivated with indigenous fruit trees, including the establishment and evaluation of provenance trials. Small-scale seedlings establishment are also in existence. The impact of NARP as it relates to indigenous fruits trees in the Northern Sub-Saharan region is however yet to be fully felt.
All stakeholders showed consistent preference for the following species: Adansonia digitata, Acacia seyal, Acacia nilotica, Acacia Senegal, Anogeissus leiocarpus, Azadirachta indica, Anacardium occidentale, Balanites aegyptiaca, Borassus aethiopum, Ceiba pentandra, Combretum microcarpum, Eucalyptus camaldulensis, Diospyros mespiliformis, Faidherbia albida, Guiera senegalensis, Gmelina arborea, Hyphaene thebaica, Lawsonia inermis, Lannea acida, Khaya senegalensis, Moringa oleifera, Mangifera indica, Parkia biglobosa, Piliostigma thonningii, Pterocarpus erinaceus, Pinus spp., Salvadora perica, Senna siamea, Tamarindus indica, Vitellaria paradoxa, Vitex doniana. Highly valued naturalised exotic fruits trees including Mangifera indica, Psidium guajava, Anacardium occidentals, Azadirachta indica and Citrus spp., were however not included in the list.