Wood Species Diversity Assessment, Yield and Abundance of Tropical Rainforest Ecosystem of Southwest Nigeria

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会议名称:2013世界木材日研讨会(2013 World Wood Day Symposium)
会议时间:2013年3月19-20日
会议地点:Karimjee Hall, Dar es Salaam, Tanzania
报 告 人:Victor Ajibola Adekunle
     Department of Forestry & Wood Technology, The Federal University of Technology, Akure, Nigeria

Abstract
The tropical rainforest ecosystem of many Southwest and Southeast Nigeria is one of the major vegetations in Nigeria. Even though It is just about 2% of the total forest area of Nigeria, it has been adjudged the most diverse, most depended upon for indispensable ecosystem services. It is the major source of timber and non-timber products. It is highly extracted for round wood. This study was carried out to examine the present status of the tropical rainforest ecosystem of southwest Nigeria in terms of wood species diversity, abundance and yield. The various functions of these wood species to both rural and urban communities were also examined. Data were collected from 11 selected forest reserves in four states of south western Nigeria. Sample plots of 25m X 25m in size were laid in alternate direction along each transect at 250m interval, summing up to 4 sample plots per 1000m transect. In each plot all living trees with dbh > 10 cm were identified and growth parameters were measured. All computed values were extrapolated for a hectare. Biodiversity indices and analytical formula were used to analyze the data. The results indicated that the rainforest ecosystem is very rich in wood species which are of high economic, ecological and traditional importance to rural and national development.  There was a total of 3,666 stem/ha, 188 species and 44 families in the forests. These species were the main sources of herbs for medicinal purposes, food, fruit, spices and several NTFPs. The Family Sterculiaceae has the highest number of stems/ha and species (677 stem/ha and 15 species), followed by Ebenaceae with 414 stem/ha while 10 of the families had only one stem/ha each. Only Moraceae family occurred in all the locations. The highest relative dominance (24.59%) and FIV (49.57) were recorded for Sterculiaceae family, followed by Leguminosae (Caesalpinioideae) with 11.50% relative dominance and 25.66 FIV. The results of the Shannon-Weiner diversity index and Evenness were 4.17 and 0.80 respectively. For the yield of the ecosystem, the mean basal area and volume per hectare were 31.79m2 and 369.76m3 respectively, the mean dbh was 27.82cm and the mean height was 15.15m. Highest proportion of the trees was in the small diameter class as expected of maturing natural forest. The high wood species diversity and yield of this ecosystem made it to be of immense importance and as a result, under intense pressure and exploitation. Models for the sustainable management of the ecosystem were recommended.

Speaker Profile
Dr. Adekunle is a Reader/Associate Professor in the Department of Forestry and Wood Technology, Federal University of Technology, Akure, Nigeria. He had more than 10 years post PhD teaching and research experience. His areas of research interest include Biodiversity Conservation and Ecosystem Services of tropical rainforest ecosystem, Forest Ecology and Inventory. Dr. Adekunle has supervised several students at both undergraduate and postgraduate levels. He has more than 30 articles in reputable journals. He has attended many local and international conferences and made oral presentations. He has also won several international research grants and fellowships. He is married with children.

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