Ethnobotanical Leaflets 12: 7-18. 2008.
Conservation of Botanicals Used for Dental and Oral Healthcare in Ekiti State, Nigeria
Kayode, Joshua and Omotoyinbo, Michael Ayorinde
Department of Plant Science, University of Ado-Ekiti, Ado-Ekiti, Nigeria.
Issued 16 January 2008
A combination of social surveys and direct field observations was used to identify and determine the abundance status of chewing stick botanicals in the tree zones of Ekiti State, Nigeria. Voucher specimens of the botanicals identified by the respondents were collected, identified and relevant information on them were documented. The relative abundance of the identified species was determined based on their accessibility when required. Thus species were classified into two groups, abundant species and scarce species. A total of 49 species belonging to 26 families were identified as being used for dental and oral health care in the study area and the various similarity measurements revealed that similar plant species were used in the three zones of the study area. Most of these species were indigenous species, the introduced species constituted 18% of the total number of the species used. Only 31% of the botanicals were cultivated in the study area and these species were cultivated mainly for other uses apart from the production of chewing sticks. The relative abundance test revealed that 34 of the species could be described as being abundant while 15 species (31 %) of the species were scarce. The major sources of these scarce species were the forests which were located far from the household areas. Chewing sticks acceptability tests conducted among the urban dwellers in the study area revealed that the use of chewing sticks cut across gender, age, educational and economic strata. However, the use of chewing sticks among the urban dwellers was governed by species availability rather than preference. Strategies that would enhance the conservation of the chewing sticks botanicals were proposed.
Keywords: Conservation, botanicals, dental and oral healthcare, Ekiti State, Nigeria.
Chewing sticks constitute an important non-wood forest product (NWFP) in Ekiti State, Nigeria where tooth cleaning with botanicals had formed part of the cultural norms. Thus despite the recent civilization, Isawumi (1978a) asserted that in Nigeria, teeth are first cleaned with chewing sticks prior to the use of modern tooth paste and brush.
Like all other NWFPs, the importance of chewing sticks, particularly to the relative low cases of dental caries and maintenance of strong teeth, are often unrecognized and/or pronounced. Some of the botanicals used as chewing sticks are now known to have a restricted occurrence in the study area where a disturbing trend of deficits of forest resources is now widely acclaimed.
At present, a gross dearth of literature on chewing sticks botanicals abounds in Nigeria. The existing few, such as El-Said et al. (1971), Enwowu (1974), Rotimi et al (1988), Akande & Hayashi (1998), Ugoji et al (2000), as well as Adekunle & Odukoya (2006), were concentrated on the antimicrobial properties of some of the botanicals while Isawumi (1978a, b, c and 1979) focused mainly on the anatomical description of some of these species. Unfortunately, all these studies had failed to consider the abundance status of the chewing stick botanicals with a view to determine the species that requires conservation and prescribe sustainable strategies for such. Thus, the study being reported here aimed to achieve these objectives.
MATERIALS AND METHODS
A combination of social surveys and direct field observations (after Lipp 1989, Kayode 2002, 2005) was used in this study, which was conducted between June 2006 and May 2007. Ekiti State (Figs. 1 and 2) was divided into three zones based on the existing political delineation (after Kayode 2004). The zones are Ekiti Central (EC), Ekiti North (EN) and Ekiti South (ES). In each zone, five rural communities that are still relatively far from urban influence were selected. The communities were, 1. Epe 2. Ipole-Iloro 3. Ido-Ile 4. Aba-Igbogun 5. Araromi-Obu 6. Eda 7. Iro-Oke 8. Aba-Oyo 9. Ogbese 10. Omi-Ogun 11. Igede 12. Itapaji 13. Ipere 14. Ifinsin and 15. Ewu. In each community, twenty respondents were randomly selected and interviewed. The interviews were conducted with a fairly open framework that allowed for focused, conversational and two-way communication (after Moinar 1989).
Also in each community, group interviews were conducted in order to determine group consensus on the chewing sticks botanicals. Four groups, each of which consisted of five individuals were interviewed in each community. Key informants made up of health, community development and forestry officials in each zone as well as dental officials of the Ekiti State Ministry of Health were also interviewed to provide secondary information on the use of chewing sticks in the study area.
Voucher specimens of the botanicals identified as sources of chewing sticks by the respondents were collected identified and relevant information on them were documented. The specimen were later treated and deposited at the herbarium of the Department of Plant Science, University of Ado-Ekiti, Ado-Ekit, Nigeria.
The relative abundance of the identified species was determined based on the time of their being assessable when required. Thus species were classified into two groups:
(a) Abundant Species: those that could be fetched within 6 hours of need, and
(b) Scarce Species: those that could only be fetched after 6 hours of need.
Similarity measures between the sampling zones were determined as:
(a) Index of Similarity (IS), according to Kayode (1999):
IS = 2C X 100/ (A+B),
(b) Jaccard Index (S), according to Gurevitch et al (2002):
S = C/ (A+B+C),
(c) Sorensen-Dice Index (SSD), according to Gurevitch et al (2002):
SSD = 2C/ (A+B+2C),
(d) Ochioi Index (SO), according to Gurevitch et al (2002), SO =
(e) Asymmetrical Similarity (SAS), according to Gurevitch et al (2002):
SAS = B/ (B + 2C).
Where A is the number of species in first site only, B is the number of species in second site only, and C is the number of species in both sites.
Chewing sticks acceptability tests were carried out among the urban dwellers in the study area. Five urban towns were selected in each zone and 10 urban dwellers were randomly selected from each town. The respondents were interviewed with the aid of semi-structured matrix. The data obtained from this test was subjected to statistical analysis using the x2 test.
RESULTS AND DISCUSSION
A total of 49 species belonging to 26 families were identified as being used for dental and oral health care in the study area (Table 1), and the various similarity measurements (Table 2) revealed that similar plant species were being used in the three zones of the study area. Most of these species were indigenous species. The introduced species among them are A. occidentale, A. indica, A. Juss, C. aurantifolia, D. erecta, H. rosa-sinensis, M. indica, P. guajava, and T. cacao. The introduced species constituted 18% of the total number of the species used. Only 15 out of the 49 species, representing 31% of the botanicals were cultivated in the study area (Table 3) and these species were cultivated mainly for other uses apart from the production of chewing sticks. Thus the provision of chewing sticks was considered as being secondary and/or tertiary products from the species. The cultivated species were mostly valued for their fruits, medicine, erosion control, hedgerow and shade (Table 3).
Results from the relative abundance test revealed that 34 of the species could be described as being abundant while 15 species, which constituted 31 % of the species were scarce (Table 4). The major sources of these scarce species were the forests which were located far from the household areas. Table 5 shows the socioeconomic classification of urban respondents. All the respondents were familiar with the use of chewing sticks while 95% of the respondents confirmed having used chewing sticks before the study. Thus the use of chewing sticks cut across gender, age, educational and economic strata. The study however revealed that urban dwellers use of chewing stick species was governed by species availability, usually purchased from retailers, rather than preference.
The relatively high proportion of indigenous chewing stick species confirmed the previous assertions of Kayode et al., (1997) and Kayode (2004) that in the utilization of botanicals, preference of dwellers in the study area had always been skewed towards the indigenous species rather than the exotics. This preference had been attributed to the long time familiarity with the indigenous species and their ethnobotanical utilization among the rural populace (Kayode and Kadeba 2001). Most of the indigenous species were developed from wildlings. Apart from the apparent lack of willingness to invest in tree planting due to increasing occurrence of land fragmentations and the time taken for trees to mature, there is a general lack of silvicultural knowledge of the indigenous species. Most of the indigenous species are high light demanders hence they are poorly represented in the sapling stage of the existing secondary forests of the study area. Most of them reproduce poorly and lacked the ability to withstand environmental calamities such as burning.
All the 15 species found to be scarce in this study (Table 4) could be said to be endangered. Most of them have stems, roots and/or leaves that are used ethno medicinally. Moreover, their collection methods have been predatory and annihilative. Such methods of collection as previously observed by Homman (1994) entailed the destruction of source(s) at such a rate that regeneration has been slower than the rate of extraction. Some of the parts collected are often discarded later. The barks of roots and stems served as important sources of chewing sticks (Table 1) in most of the identified botanicals. Debarking of stems and roots had been identified as one of the highest destructive extractive technique commonly observed in Nigeria (Fasola and Egunyomi 2002). Studies by Cuningham (1988), John (1988) and Peters (1996) had revealed that debarking often kills plant species. Although most of the chewing sticks species were perennials, most, as observed by Shinwari and Khan (2000) required prolonged period of growth with considerable number of years required to reach flowering and fruiting stage, thus minimizing their regenerating possibilities. The relative regrowth capabilities of the indigenous trees and shrubs in the study area were not studied. Thus, predation and annihilation usually results in increasing scarcity of species.
Field observation during the study revealed that there is an increasing conversion of valuable natural environment to monoculture plantation of exotic timber and agriculture in the study area, thus there is the likelihood of the continued erosion of botanical diversity and the common traditional values of the ‘minor forest products’ such as chewing sticks. Most of the identified species were essentially rich in natural products, most of which were relatively free of side effects, thus they may become the base for the development of medicine, a natural blueprint for the development of new drugs.
In conclusion, an urgent conservation strategy should be evolved to preserve these species for the use of the present and future generations. Such strategy should encourage the domestication of botanicals identified, improve their methods of harvesting and processing, research further on the biology of the spices with the aim of providing clue to their ecology, enlighten the populace about the dangers in the loss of biological diversity, and accommodate the indigenous farmers in both planning and execution of the strategy. Also, in-situ and ex-situ conservation methods should be embarked upon. These, according to Shinwari and Khan (2000) should involve the protection of plant species in their natural habitats followed by ex-situ devices by growing important species and subsequently re-introducing them into their natural environment.
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Table 1. List of chewing sticks botanicals in Ekiti State, Nigeria.
Table 2. Similarity measures on the occurrence of tree flora in the three zones of the study area.
Fig: 1: Map of Nigeria showing Ekiti State of Nigeria.
KEY: X: Ekiti Central , Y: Ekiti South, Z: Ekiti North.
Fig. 2: Map of Ekiti State Showing the study sites used.
Table 3. List of cultivated chewing sticks botanicals in Ekiti State, Nigeria.
Table 4. List of scarce chewing sticks species in Ekiti State, Nigeria.
Table 5. Socio-economic classification of respondents’ urban dwellers in Ekiti State, Nigeria.