0424-A2

The Uses of Forest Leaves in Omo Forest Reserve, Ogun State, Nigeria

Akinyemi Joel Ogunleye^[1]

ABSTRACT

A survey of the use of forest plant leaves in household nutrition and health care in Omo Forest Reserve was carried out. The result shows that 39 plant species in 27 families are used either as food or for health care or both. Of the 39 species, 29 or 53.8% are trees, while the least used are the herbaceous climbers. The majority of the plants are used as concoction that is, agbo in Yoruba language. There is a prevalent use of the plant leaves for the treatment of malaria diseases in the study area. The range of uses suggests the great importance of forest plant leaves in health care delivery among rural dwellers. However, what is not known is the quantity of the plant materials harvested.

INTRODUCTION

Leaves perform functions, which are crucial to the survival of plants. Some of the functions include manufacture of food by the chloroplasts in the presence of sunlight, interchange of gases, such as CO₂ and O₂ between the atmosphere and the plant body, the carbon-dioxide for manufacture of food by green cells only and Oxygen for respiration by all living cells. Apart from biological functions, the leaves of forest plants also play some socio-economic roles in the life of man. They are an integral and important part of non-timber forest products. The leaves are put into different uses, which include food, medicines, roofing, household utensils and cultural values (Adekunle, 1998). Forest plants foods especially leaves contribute directly to household nutrition ad dietary supplements in Nigeria as reported by other authors such as Denton and Ojeifo (1993). For Example leafy vegetables are obtained from various species in the different ecological zones of Nigeria, Adansonia digitata (Kuka in Hausa) is common in the savanna zones while species such as Ghetum sp. (Okasi-Igbo), Crassoephyllum ruben (Ebolo-Yoruba), Telfaria occidentale (Eforoko-Yoruba), Myranthus arboreus. (Ujanjan, Igbo; Ebisere, Yoruba) and Pterocarpus sp. (Oha-Igbo; Yoruba) are obtained from the forest zones. They are used daily to enhance the flavour of foods. Their consumption increases when food supply may be low especially before harvest time. The leaves of Triumfetta rhomoboidea are consumed in the Cameroon as emergency foods in an average of 19 out of 20 meals.

According to Adebisi (1999) leaf extracts of Phyllanthus amarus and Solenostenon monostachyus taken twice daily for two weeks have been recorded effective against arthritis and for the treatment of asthma. Datura metel leaves prepared into herb tea and smoked with pepper would decongest the chest. Eka (1991) reported the use of plant leaves in the treatment of guineaworm (Dracunculiasis) infection at Mkpam village in Cross River State, Nigeria. They include Aspilia africana, Cyathula prostrata, Cyimbopgon citrates, Portulaca oleraceae and Sida acuta.

Apart from food and medicines, forest plant leaves are also exploited for other purposes in Nigeria. The Igbos value the leaves of Onchocalamas sp. For Kola nut storage while leaves of Marantochloa flexuosa, Sacophyrynium sp. and Thamatococcus danielli are utilized for wrapping food items such as agidi, ukpo and allele. Halea ciliata (Abura) leaves are common among the Yorubas for wrapping Kola nuts. Similarly, the leaves of Thamatococcus danielli. Tectona grandis and Megaphirinium macrostachymum are used for wrapping and preservation of food items.

Trade and commercial activities in forest leaves have been reported in Nigeria. Adekunle (1998) reported annual financial benefits as a result of sale of some forest leaves in Omo Forest Reserve. Example of such leaves are as follows: Telfaria occidentale, N6,000; Crassoephyllum rubens N7,000. Thamatococcus danielli (wrapping leaves), N42,000; Tectona grandis (wrapping leaves) N9,000 and Halea ciliata (wrapping leaves) N16,000 respectively per annum.

There is a growing interest in traditional medicine largely because of green consumerism and the current resurgence of interests in the use of natural products in developed countries, for new phytopharmaceuticals for the prevention and cure of deadly diseases such as cancer and AIDS (De Silva, 1997). This interest is leading to explaining the demand for medicinal plants in native and international healthcare. Information is scanty about the more than 35,000 plant species beings used in various human cultures around the world for medicinal purposes (FAO, 1999). Many of this species are subjected to uncontrolled local and external exploitation.

This study therefore investigates the use of forest plant leaves in OFR, Ogun State, Nigeria. This is in line with the Chiang Mai Declaration of 1998; which in part drew the attention of the UN, its agencies and member stats, international and non-governmental agencies to the importance of medicinal plants. The study is also in line with Agenda 21 and forest principles (UNCED, 1992) in which NTFPs has been identified as an important area requiring concerted action in order to capture their potentials for contributing to economic development, employment, and income generation in an environmentally sound and sustainable manner (Chandrasekharan, 1995).

MATERIALS AND METHODS

The study was carried out in Omo Forest Reserve (OFR), the largest forest reserve in Ogun State covering 1368.06km² and situated in the Ijebu East and North Local Government areas of the State. OFR is one of the few remaining large blocks of high forest in Nigeria. The forest estate has an estimated distance of about 20 kilometers (km) from the Atlantic coast in its southern-most parts (Okali and Ola-Adams, 1987).

The reserve was created in 1925 and administratively divided into four areas. These are areas J1, J3, J4 and J6. The topography is characterized by an undulating terain dominated by slopes up to 15% with elevation reaching 150 meters on a few rocky hills. The reserve is drained by the River Omo, which traverses it; and River Oni which forms the eastern and southern boundaries. The OFR vegetation is characterized by a mixed moist semi-evergreen rainforest type of vegetation (White, 1983).

The exploitation of both timber and Non-timber products are going on in the reserve. Other socio-economic activities being carried out in the reserve include farming, hunting, fishing, saw milling and trading. The reserve is a center for research and educational activities. This include the 460 ha Strict Nature Reserve (SNR) under the Man and Biosphere Projects (MAB).

METHODS OF DATA COLLECTION AND ANALYSIS

Pre-tested questionnaires were distributed to 100 respondents in each of the area J1, J3, J4 and J6 using the snowball sampling techniques. (Mccall and Simmons, 1969). The questionnaires were made up of both close and open-ended questions. Issues such as local name of the plants, parts used and uses were addresses by the questionnaires. The respondents were made up of farmers, hunters, traditional doctors and herbals sellers. Questionnaire information was complemented by visits to some local markets within the catchment’s areas of the study area. The markets are Orita J4, Ijebu-Ife. Ita-Ale (Ijebu Igbo), and Apoje. This was for visual observation of some of the herbal materials on sale in the markets, and along the roads sides. Other knowledgeable informants such as village heads, headhunters, and herbal materials sellers were contacted for further information on forest plant leaves utilization. Taxonomic texts were contacted for the scientific names of the plant species recorded. The data collected were analyzed and presented in tables.

RESULTS AND DISCUSSION

Table 1 summaries the details of the plant leaves utilized for food and medicines in the study area. The leaves of 39 species in 27 families are used for food and medicines. Leaves of tree plants had 53.85%, while shrub, herbs and herbaceous climbers had 15.3%, 20.51% and 10.26% respectively (Table 2). This result showed that the people of OFR are familiar with the use of forest plants especially leaves for food and health care. The massive clearing and logging activities going on in the study area are not consistent with sustainable utilization of forest resources especially leaves. Although, forest plant leaves collection appear to be providing poor communities in the study area with cash income and has probably saved some renewable resources from destruction yet, Ola-Adams (1996) reported that over exploitation and forest clearing for monoculture plantation are among the prominent factors causing loss of biodiversity especially in the study area.

The leaves of about 14 of the plant species are put into more than two uses. This could affect the growth of the plant due to over-utilization and hence put natural regeneration into jeopardy as expressed by Oluwalana and Adekunle (1998). Accordingly, Browder (1992) demonstrated that collecting NTFPs does not benefit rural households greatly. Consequently, living standards among the leaf collectors of the study area compare poorly with the meager socioeconomic norms of the rural Nigerians.

Thirteen medicinal use categories of plant leaves were identified of which malaria fever was found predominating (Table 3). This involved about 17 plant species. They are either used singly or in combination with other herbs. This trend could be as a result of the fact that malaria fever is a tropical disease and man must have been searching for cures leading to the use of many different plant species to effect cure. Some information about plant use to cure diseases might be with a few individuals especially the old people. Once these people die the information is lost. In effect there is information depletion.

Table 1: Some uses of plant species leaves in household nutrition and health care in Omo forest reserve

Source: Field survey. (U) Uncultivated, (C) Cultivated

Table 2: Plant habits by percentage.

Source: Field survey.

Table 3: Medicinal categorization of Plant leaves in the study area.

Source: field Survey

CONCLUSION

The Concern for deforestation and desertification has made timber, fuel-wood and charcoal popular in forest resources management. The leaf extraction can lead to environmental damage. It is significant to point out that the same plant populations are harvested continually by some destructive harvesting techniques especially when market pressures begins to build.

However, this study has revealed that NTFPs such as forest leaves are equally important as timber especially in the area of health care delivery system of the rural dwellers. Lasting increases in the value of NTFPs might not benefit tropical forest dwellers even if the open access problems that lead to destructive harvesting are resolved.Therefore, the political changes in Nigeria due to democratization should enhance the formulation of new forest policies which would be wholistic enough to cater for the sustainable utilization of all NTFPs in Nigeria including forest leaves.

REFERENCES

Adebisi, L. A. 1999: Prevalence and utilization of some medicinal plants in Agro-forestry systems: A case study selected areas in Southwestern Nigeria. J. Trop For Resources Vol. 15.1 pp 30-39.

Adekunle, M. F. 1998: Survey of Non-timber forest product (NTFPs) and their uses in Ogun State, Nigeria: A case study of Omo Forest Reserve. M. F. Thesis University of Agriculture, Abeokuta Nigeria (unpublished) 74p.

Alwis, L. 1997: A bio-cultural medicinal plant conservation project in Sri Lanka. In: Medicinal Plants for forest conservation and health care. Non wood forest products (NWFP) 11, FAO Rome pp 100-108.

Browder, J. 1992: The limits of extractism. Bioscience 42, 174-181. In: Adamowicz, W.L; Boxall, P.C; Luckert, M.K; Philips, W.E and White, W.A (Eds.). Forestry, economics and the environment. CAB International. 275pp.

Denton L.and Ojeifo, I. M. 1993: Neglected vegetable crops in Nigeria. In: Lost crops of Nigeria: implication for food security. Okojie J. A. and Okali D. U. U. (eds) University of Agriculture, Abeokuta, Nigeria pp 5 - 107.

De Silva, T. 1997: Industrial Utilization of medicinal plants in developing countries. In: NWTP 11, FAO Rome, pp 34-44.

Bhatia, S and Khotani, A. 1996: Community registers for documenting local uses of biological diversity. Bulletin of the Working Group on Traditional Resources Rights 2: 9-10.

Chandrasekharan, C. 1995: Terminology, definition and classification of forest products other thank wood.In: Non-wood forest Product 3, FAO, Report 3 Rome 1995. Pp 345 - 380.

Dutta, A. C. 1981: Botany for degree students, 4^th Edition Oxford University Press, Oxford, London. Pp 57 - 58.

Eka, I. 1991: Herbal treatments of Guinea worm disease at Mkpani, Cross River State, Nigeria. The Nigerian Field Vol. 56 part 3 -4 October, 1991 pp 121-126.

Food and Agriculture Organisation (FAO) 1999: A look at medicinal plants: In Non-wood News No. 6 (March 1999) FAO. Rome Pp 109 -115.

McCall, G. J. and Simmons, J. 1969: Issues in participants observation. In: The practice of social research. Babbie, E (ed). Wadsworth Publishing Co. Belmont, California U. S. A

Ola Adams, B. A. 1996: Conservation and Management of Biodiversity. In: Proceedings of BRAAF seminar, 9 - 11 Jan. 1996, Omo Biosphere Reserve, B. A. Ola-Adams and L. O. Ojo (eds) Pp 118 - 133.

Okali, D. U. U. and Ola Adams, B. A. 1987: Tree population changes in treated rainforest at Omo Forest Reserve, South Western Nigeria. Nig. Jour. Of Tropical Ecology 3: 291: 313.

Oluwalana, S. A. and Adekunle, M. F. 1998: Forest Plant Root in Household nutrition and Healthcare in Abeokuta, Ogun State, Nig J. Trop. For Resources Vol 14, 1 (1998). Pp 120-136.

UNCED 1992: United Nations Conference on Environment and Development, Rio de Jainero, 3^rd - 14^th June 1992. Forest Support Programme USAID memo. USA 1992 pp 51.

Van Seters, A. P. 1997: Forest based medicines in traditional and cosmopolitan health care. In: Non Wood Forest Products (NWFP) No 11 FAO, Rome Pp 5 -11.

White, F. 1983: The Vegetation Map of Africa, UNESCO Paris.