Medicinal plant species collected from the survey area with their medicinal values.
The loss of biodiversity in Nigeria is intensifying distressingly, which happened to be more prominent in some states across northwestern as well as north eastern geopolitical regions of Nigeria and was threatened by the confrontational effect of desertification. The Sahel region and some part of the savannah region bordered which faced the menace of drought and desertification which lead to so many factors like soil erosion, distraction of the ecosystem entirely. Moreover, the plants destroyed were mostly aromatic plants which served as medicines in curing many ailments and diseases contributed to the economic status of the communities found in the Sahel. The plants species became threatened to the human practices by noticing their effects for their well-being. Consequently, among the species that were threatened include: Neocarea macrophylla Prance ex F.White (Gawasa), Sclerocarya birrea (A. Rich) Hochst. (Danya), Detarium microcarpum Harms. (Taura), Prosopis africana, (Kirya), Acacia africana, Acacia nilotica and Azadirachta indica. Hence, the major concern of this chapter is to assess some of the threatened species found in the Sahel region, Nigeria and to highlight the valuable medicinal plants at risk of extinction according to the guidelines of the International Union for the Conservation of Nature (IUCN).
- dessert plants
- medicinal plants
The loss of biodiversity in Nigeria is intensifying distressingly (“Assessment of the threats to biodiversity” Convention on Biological Diversity [CBD]), which happened to be more prominent in some states across northwestern as well as north eastern geopolitical regions of Nigeria and was threatened by the confrontational effect of desertification, posing a substantial threat to the well-being of the populace . The Sahel region and some part of the savannah region bordered with Niger Republic faced the menace of drought and desertification that leads to soil erosion and distraction of the ecosystem entirely (Figure 1). The confrontational effect is caused by the rampant cutting of trees, loss of ground cover and continuous overgrazing by livestock of the Fulani herdsmen. Moreover, the plants destroyed were mostly aromatic and medicinal plants gathered, traded and used by communities in Sahel as source of livelihood. Consequently, among the species that were threatened include
1.1 Loss of biodiversity
Evidences showed that the biodiversity has been unprecedentedly lost at a higher rate in many parts of Nigeria, which are mostly human related factors such as industrialization, technological advancements and settlements for urbanization. Biodiversity loss in Nigeria is mainly due to poor law enforcement, high demand for forest products and cultural practices. In addition, clearing of vegetation haphazardly leads to loss in biodiversity. However, biodiversity loss may also due to some agricultural and livelihood practices such as firewood cutting and gathering, bush burning, logging and overgrazing. Since 1990s, some large farm has caused enormous deforestation of the natural habitats depicting as the major source of loss. Thus, drastic depletion of fire-wood species like neem tree,
1.2 Plants species utilization patterns
Northern Sahel region of Nigeria nutritional habits are equivalent with slight variations influenced by traditional backgrounds. All the trees selectively protected in the parklands provide one or combinations of the following concrete and immaterial services: food items (edible fruits, nuts, leaves, flowers, livestock fodder, fuel wood, medicine, esthetics, shade, agricultural tools and cooking utensils, avenues, and other services such as ropes, fibers, tannin, manure, latex gums and oils). Patterns of exploitation are quite similar for the entire region. However, additional trees were protected based on their medicinal values and food, Fire wood (fuel energy and heating) stand equally of importance, with the exception of
Nevertheless, small number of both species was assessed due to the fact that, many were threatened, deteriorated as a result of human and edaphic factors. Many were not assessed in the IUCN Red list due to the aforementioned factors that pressurized on them to be disappeared or not even listed in the whole list . All stakeholders showed consistent preference for the following species:
1.3 Other threatened species
A considerable numbers of indigenous species were reported to have declined in some years back. The focus groups credited the decline of these species due to some activities (land degradation) occurred . Certain percentages have shown that the species faced a lot of problems (Ranging 36%-60%) of all the species found in the Sahel. The common plants species involved across the towns and villages were
Survey was conducted across the region in collating the reliable information in conjunction with search engines for the peer reviewed journals and books in getting sound and reliable information with regards to the threatened species found in Sahel region. Information on the uses of plants especially those with medicinal properties were carried out by using a survey form and interviewing traditional medicine practitioners, herbs gatherers and sellers. Images of the plants mentioned were taken in the natural habitat and voucher specimens were collected and preserved following the standard herbarium technique.
2.1 Collection of plant materials and identification
Plant species collected were organized as complete herbarium specimens and identified as outline by the rules of herbaria. Plant materials were identified and authenticated by a plant taxonomist in person of Dr. Yusuf Nuhu, from the Department of Plant Biology, Bayero University Kano, Nigeria. All identified plants specimens were given vouchers number as outline in (Table 1).
|No.||Botanical name||Family||Common name||Local name||Habit||Part(s) used||Voucher no.|
|1.||Malvaceae||Baobab tree||Kuka||Tree||Stem, leaves||MSA36|
|2.||Combretaceae||African birch||Marke||Tree||Stem, leaves||MSA29|
|5.||Fabaceae||White or winter cassia||Runhu||Herb||Leaves||MSA316|
|7.||Combretaceae||Senegal Gueira||Sabara||Shrub||Leaves, root, gall||MSA32|
2.2 Data organization
2.3 Relative frequency of citations
It was used to authenticate the local benefit of each species in the study areas. Its index was determined by dividing the number of informants cited useful species (FC) by the total number of informants participated in the survey (N), as viz.: RFC = FC/N .
The collated plants were identified and authenticated in line with the responses from the respondents. They were given voucher numbers as outlined in Table 1 below, as well as the citation frequencies were procured based on the procured data as shown in Table 2.
Ethnobotanical information gathered were quantitatively analyzed using various quantitative indices which made up of: Relative frequency of citation (RFC) and Frequency of citation (FC) [14, 16]. It has been proved that, the RFC was happened to be (0.25) for the gastrointestinal disorders among the collated medicinal plants , which conforms to the present study as pinpointed in Table 2. It has been revealed that, 80% of African populace relied on herbal/traditional medicine to treat many ailments due to the in availability and affordability of the commercial orthodox. In Northern Nigeria, people make used of combined plants formulations to get rid of gastric ulcer problem, which include
5. Case study: neem tree
5.1 An overview
5.2 Neems characteristics
Shade is not the only appreciated characteristic of neem. It has so many uses and potentialities for future usage, that was why it considered as miraculous, it is used for furniture, fuel and in construction, it also attract bees and honey flavor. Neem has been declared as local pharmacy. In India, people use neem twig to prevent from teeth damage. It also cured skin disorders, enhanced tonic, treats infectious diseases and fevers .
5.3 Neem as part of the West African trees
Neem was brought to West African region through Ghana in the year 1919 and 1927. It became familiar and well spread across towns, villages and cities including Sahel regions. Neems have been declined due to some biotic and abiotic factors which lead to its deterioration in the whole region; it served as a great set back in the development of the Sahel region . Moreover, certain factors also lead to neem declination such as; defoliation by insects, drought or an exposure to pollutants at times certain microbes’ infestation may lead to decline in the neem population as well, similar case has been reported on
5.4 Uses of neem tree in the Sahel
Native to India and Myanmar, the neem being a member of the family Meliaceae together with the mahoganies. It does possessed compound leaves of nine to 15 leaflets which are dark green in color. The fruits are yellow-green to green, smooth, olive-shaped and about 2 cm in length, with a sweet pulp enclosing a seed. Consequently, Neems can grow up to 30 m in height and 70 cm in diameter, with broad, dispersal pinnacles that retain their foliage all year round. Neem due to its attributes, it is highly valued .
Neem is a member of the mahogany family. It is moderately heavy, with a specific gravity varying from 0.56 to 0.85 (average, 0.68). With a strong smell when freshly cut. Although simply sawn, worked, refined, and glued, it must be dried wisely as it often splits and warps. It also splits easily and nailed. However, it is widely used in carts, tool handles, and agricultural implements. In South India became very common furniture wood. It is aromatic, attractively spotted, narrowly linked, and then medium to be coarse in texture. Although it lends itself to carving, it does not take a high polish. The timber appeared durable even in exposed situations. It is rarely attacked by termites, its resistant to woodworms, and makes useful fence posts and poles for house construction. Also used as pole wood especially in developing countries; the tree’s capability to resprout after cutting and to regrow its canopy after pollarding makes neem highly suited to pole production. In view of the above, those rigorous activities have threatened its population as well .
Neem became threatened due to its useful oils produced; it usually burnt in lamps throughout many countries. Its wood has long been in the practice of burning for food as well. Furthermore, husk produced by the seeds, mainly employed as fuel. Because of the tree’s good growth and valued firewood, it has become the most vital plantation species in northern Nigeria. It is also grown for fuel around large towns. Charcoal made from this neem wood stands excellent quality, with a rich value only somewhat below that of coal from Nigeria’s some of the eastern parts. Neem is very common, especially in towns and villages, in the northern regions despite been threatened .
5.4.3 Medicinal values of neem
Although masses in India insisted on the effectiveness of neem actions in treating many ailments, the pharmacological properties have hardly been threatened to severe trials with controls. It has been proclaimed that, neem trees have been in practice in curing many diseases most especially the oil extracted from it, but many findings contradict with the claim to be wise enough in curing children’s at the tender age . Neem being a Meliaceae family, a famous plant with medicinal attributes since time immemorial.
5.5 Neem needed a tougher law of protection
Neem deterioration is increasingly appeared in large areas of Nigerian states most especially in neighboring countries like; Niger, Cameroun, Chad and Mali as a result of inaction to the problem occurred in the areas by the government and non-governmental agencies that can curve the menace. Certain measures can lead to the solution to the neem declination which will definitely enhance the socioeconomic effects of neem deteriorations . Neem tree served as an insecticide by possessing some pesticidal components, it attacks so many as widely practiced in West Africa. But in some parts of the world, such as India, Far East Asia, it defoliates and also kills the tree. Reports have been documented that an oriental yellow scale damaged several neem trees in across West African countries including North eastern Nigeria and Eastern Niger, which lead to an eminence drought in the Sahel, which turned many neem trees weak and sickly .
The biodiversity has been lost at a higher rate in most parts of Nigeria especially in Sahel region, where people solely depend on plants to carry out their life activities. Many factors have contributed a lot most importantly human related, such as: medicinal purposes, industrialization, technological advancements and settlements for urbanization. Moreover, direct causes of biodiversity loss in Nigeria made up of; poor law enforcement and weak laws, much demand from forest products, cultural practices which contributed tremendously in cutting down of vegetation and lead to loss in biodiversity as depicted, many plants would likely to be in extinction if care is not much taken. Proper awareness on the sustainable use of these mostly utilized species within the Sahel region should be forcefully and continuously communicated to the communities living of the resource so that they could one day be the custodian and guardian of their forests and natural resources. We believed that effective conservation and sustainable used of natural resources got to be community based, coupled with national and international law to safeguard their livelihood.
We really appreciates the Yobe State University and Universiti Putra Malaysia for funding and facilities rendered for the preparation of this publication. We are thankful to the traditional medicine practitioners, herbs gatherers and sellers for their cooperation in sharing their knowledge of plants.
Conflict of interest
The present book chapter contribution has no conflict of interest declared.