International Forestry Review, 16, 5, 65.

 Journal

 Conservation And Socio-economic Importance Of Some Agroforestry Fruit Tree Species: Farmers’ Participation, Tree Growth Characteristics And Market Assessment.

 Onyekwelu, J. C.; Stimm, B.

 2014

Deforestation and demographic pressures have greatly depleted populations of indigenous forest fruit trees that produce socioeconomically important non-timber forest products (NTFPs). We assessed farm-level growth characteristics, market potentials and farmer’s participation in conservation of Chrysophyllum albidum, Irvingia gabonensis and Garcinia kola in rainforest and derived savanna ecosystems of Nigeria. Growth measurements were made on 50 trees of each species from ten villages. Two sets of questionnaires were used to obtain information from 30 farmers and 60 marketers of the species fruits/seeds in 12 urban and rural markets. The trees were old (32.3–43.5 and 19.5–35.2 years for C.albidum and I.gabonensis) and large (DBH: 36.0–64.3 cm; 19.5–61.3 cm and 46.3 cm for C.albidum, I.gabonensis and G.kola, respectively). Farmers’ participation in conservation (planting) was higher in derived savanna (40–80%) than rainforest (2–6%). Conservation is male dominated (76–92%) while marketing is female dominated (60–100%). Annual fruit production ranged from 500 to 1 000, depending on species. Averagely, farmers sold 60% of their fruits/seeds and earned between US$300 and US$1 300 annually, with income highest and lowest at farm-gate and urban market, respectively. This income contributed 21–52% to total household annual income. Thus, increased tree planting could substantially improve farmers’ livelihood and economic sustainability 

 European Journal Of Agriculture And Forestry Research, 2(3): 43-51.

 Journal

 Socio-Economic Importance Of Chrysophyllum Albidum G. Don. In Rainforest And Derived Savanna Ecosystems Of Ondo State, Nigeria.

 Bolanle-Ojo O.T. And Onyekwelu J.C.

 2014

This study was carried out to determine the socio-economic importance of Chrysophyllum albidum in rainforest and derived savanna ecosystems of Ondo State and examines its level of domestication. From each ecological zone, a local government area (LGA) with good concentration of C. albidum trees was selected. The study covered a total of ten villages (i.e. five from each ecosystem). From each village, five farm households with C. albidum trees on their farms were selected. A structured questionnaire was administered on the head of each household. Results identified evidence of C. albidum trees domestication in the two ecosystems. C. albidum fruit is economically important in the two ecosystems and contributes to the socio-economic life of the people. Factors affecting the price of C. albidum fruits in the two ecosystems were fruit taste and fruit size. Thus, the demand will improve if sweeter and bigger sized fruits are produced through domestication programme. 

 International Journal Of Scientific & Technology Research, 3 (10): 178 - 185

 Journal

 Tree Species Diversity And Density Pattern In Afi River Forest Reserve, Nigeria.

 Aigbe H.I, Akindele S.O., And Onyekwelu J.C.

 2014

Afi River Forest Reserves in Cross River State, Nigeria, was assessed for tree species diversity and density pattern. Multistage (3 stage) sampling technique was adopted for data collection. 10 tertiary plots were randomly established within the secondary plots and trees randomly selected for measurement within the tertiary plots (0.20 ha). Growth data including: diameter at breast height (dbh, at 1.3m); diameters over bark at the base, middle and top; merchantable height and total height were collected on trees with dbh ? 10 cm in all the 10 tertiary sample plots. The results indicate that an average number of trees per hectare of 323 (68 species) were encountered in the study area. Population densities of the tree species ranged from 1 to 29 ha-1. This means, some tree species encountered translates to one stand per hectare. Pycnanthus angolensis was the most abundant with a total of 29 tree/ha. The basal area/ha in the study area was 102.77m2 and the species richness index obtained was 10.444, which indicate high species richness. The value of Shannon-Wiener Index (HI) is 3.827 which is quite high. The results show that the forest reserve is a well-stocked tropical rainforest in Nigeria. The high species diversity and the relative richness in timber species of the forest reserve does not correlate well with the abundance because the abundance of each of the species was quite low and density poor. However, the presence of higher percentage of the lower diameter tree in the forest reserve indicates that the forest reserve is vigour and healthy. 

 ISRN Forestry, Http://dx.doi.org/10.1155/2013/376247

 Journal

 Poverty Alleviation Through Optimizing The Marketing Of Garcinia Kola And Irvingia Gabonensis In Ondo State, Nigeria

 Agbelade, A.D. And Onyekwelu, J.C.

 2013

The paper examines poverty alleviation through optimizing the marketing of Garcinia kola and Irvingia gabonensis in Ondo State, Nigeria. Data for this study were collected using structured questionnaire. Two categories of pretested structured questionnaires were used to obtain information from the respondents (farmers and the marketers of the species). Data analysis was done using descriptive analysis, and Student t-test was used to compare the income generated by the producers and the marketers of the fruits of the tree species. In addition, analysis of variance (ANOVA), arranged in randomized complete block design, was employed to test the significance of price variable across the three market structures (i.e., farm gate price, rural market price, and urban market price).Marketing of forest fruits species is a profitable enterprise with an average profit of 119,123.37 per marketer per month.The analysis of variance for the two forest fruit species indicated that Irvingia gabonensis generated the highest annual income in rainforest ecosystem while Garcinia kola generated the highest annual income in derived savanna ecosystem.Major constraints militating against these forest fruit species are poor market access and infrastructure development.The paper recommended among other things that domestication and interventions of these forest fruit species should be encouraged for proper management and sustainability. 

 Nigerian Journal Of Forestry, 43 (1): 53 – 67.

 Journal

 Volume Equation For Oban Tropical Forest Reserve, Cross River State, Nigeria.

 Aigbe H.I, Akindele S.O., And Onyekwelu J.C.

 2013

Nil 

 Journal Of Forestry Research, 23: 253 – 260

 Journal

 Soil Microbial Biomass And Population In Response To Seasonal Variation And Age In Gmelina Arborea Plantations

 Onyekwelu, J.C.

 2012

We investigated the Effects of plantation development, seasons, and soil depth on soil microbial indices in Gmelina arborea plantations in south-western Nigeria. Soil samples were obtained from the soil depths of 0–15 and 15–30 cm from plantations of six different ages during the rainy season, dry seasons, and their transitions. We used plate count and fumigation-extraction methods to determine microbe population and microbial biomass carbon (MB-C) and nitrogen (MB-N), respectively. Plantation age did not affect microbial indices, implying a non-significant effect of plantation development on microbial communities. It could also imply that soil microbial indices had already stabilized in the sampled plantations. Seasonal variation and soil depth had significant effects on microbial indices. At 0–15 cm soil depth, mean MB-C increased from 50.74 ?g g?1 during the peak of the dry season (i.e. March) to 99.58 ?g g?1 during the peak of the rainy season (i.e. September), while it increased from 36.22 ?g g?1 to 75.31 ?g g?1 at 15–30 cm soil depth between the same seasonal periods. Bacteria populations and MB-N showed similar increasing trends. Correlations between MB-C, MB-N, microbe populations, and rainfall were positive and linear. Significantly higher microbial activities took place in the plantations during the rainy season, increased with soil wetness, and decreased at greater soil depth. 

 Nigerian Journal Of Forestry, 42 (1): 58 – 67

 Journal

 Effects Of Light Intensities On Seed Germination And Early Growth Of Chrysophyllum Albidum And Irvingia Gabonensis Seedlings

 Onyekwelu, J.C., Stimm, B., Mosandl, R. And Olusola, J.A.

 2012

The importance of light intensity on tree growth and survival has been documented. Naturally, there tends to be a certain amount or level of light that stimulates efficient growth of tree seedlings. The effects of different light intensities on germination and early growth of Chrysophyllum albidum, Parkia biglobosa and Treculia africana seedlings were investigated. The treatments were 100%, 60%, and 40% light intensities, under forest canopy (control I), and open sky (control II). Three hundred seeds of each species were sown under each treatment and germination monitored for up to 80 days after sowing depending on species. Afterwards, seedling growth characteristics (total height, collar diameter, number of leaves and biomass production) were monitored on 30 uniform seedlings for three months. The experiment was arranged in Completely Randomized Design. Except for T. africana seeds, light intensity significantly affected seed germination. Light intensity significantly affected early growth of seedlings of all the species. For P. biglobosa, plant height was higher under low light environment (40% and 60% light intensities) while seedlings grown under high light environment (open sky and 100% light intensity) had higher collar diameter, higher number of leaves and accumulated more biomass. For C. albidum, seedlings under high light environment (open sky and 100% light intensity) died shortly after germination, indicating that full exposure to light has adverse effect on the seedlings. Except for collar diameter, C. albidum seedlings under 40% and 60% light intensities had similar growth rates. C. albidum seedlings under forest canopy had very poor growth, suggesting that the seedlings do not tolerate high shade environment. T. africana seedlings under low light environment (40% and 60% light intensities) were significantly taller than those under high light environment while high light environment had significantly greater effect on collar diameter, number of leaves and biomass production. The information from this study will enhance the understanding of early growth characteristics of these socio-economically valuable food tree species, which is important for their successful domestication. 

 Springer Dordrecht, The Netherlands, Pp 109 – 117

 Others

 Managing Short Rotation Tropical Plantations As Sustainable Source Of Bioenergy. In: Silviculture In The Tropics (Günter, S. Weber, M., Stimm, B. And Mosandl, R., Eds).

 Onyekwelu, J.C.

 2011

Renewable energy has been identified as a promising option for reducing the heavy dependence on fossil fuels. The global use of bioenergy is equivalent to nearly a billion tons of oil and contributes about 10% of world’s primary energy demand. Bioenergy is expected to become a key future energy resource. Short rotation energy plantation species are characterized by fast growth rate and high yield. Depending on tree species, rotation age, and biomass yield, energy yield from short rotation energy plantation could range from 312 to 9,792 GJ ha 1. However, allowance must be made for branch and foliage biomasses that are usually left on site after harvesting as well as for the overall low efficiency of converting biomass. The current and expected future increase in world food prices, partly occasioned by the competition between resource use as food and biofuel feedstock, calls for reconsideration in the use of edible crops as bioenergy feedstocks. Future directions will be the use of resources that are inedible, cost-effective, high yielding, and easy to sustain as bioenergy feedstocks, as well as wastes from forestry and agrifood industries, domestic and industrial products. 

 Springer Dordrecht, The Netherlands, Pp. 399 – 454.

 Others

 Plantation Forestry. In: Silviculture In The Tropics (Günter, S. Weber, M., Stimm, B. And Mosandl, R., Eds).

 Onyekwelu, J.C, Stimm, B. And Evans, J.

 2011

Planting trees in tropical countries is becoming an increasingly important forestry activity as many tropical countries that depended on wood supply from natural forests are recognizing the need to establish plantations to augment supplies from dwindling and unsustainable natural forests. The total area of tropical forest plantations increased from about 6.7 million ha in 1965 to 109 million in 2005. Though most species used for tropical plantations are fast growing, their growth rate can be improved substantially through appropriate silviculture such as site-species matching, site nutrient management, use of hybrid species (clonal plantation), etc. This chapter reviews recent advances in tropical forest plantation establishment and management. Subjects that were specifically covered include: extent of tropical forest plantations, principles of productive forest plantation establishment and management, growth and yield of important tree species, silvicultural techniques for improvement of growth, impact of new aspects for silviculture, etc. Two insightful and demonstrative case studies were also presented to illustrate key points. 

 Springer Dordrecht, The Netherlands, Pp. 455 – 462.

 Others

 Sustainability Of Site Productivity In Tropical Forest Plantations: Case Study Of Gmelina Arborea Plantations In Tropical Rainforest, Nigeria. In: Silviculture In The Tropics (Günter, S. Weber, M., Stimm, B. And Mosandl, R., Eds).

 Onyekwelu, J.C.

 2011

The fast growth rate and high productivity of tropical plantation tree species and their high nutrient demand have raised site sustainability concern. The effects of fast-growing Gmelina arborea plantations in the tropical rainforest region of Nigeria were investigated. Soil physical, chemical, and biological properties of plantations of different ages as well as between old growth Gmelina plantation and adjacent degraded natural forest were comparable, suggesting that plantation development did not have adverse effect on soil nutrients. However, this only applies if the plantations are managed on long rotation, as short rotations would lead to massive site nutrient export. Sustainability of productivity during the next rotation is likely to be determined by factors such as harvesting methods of current stands and management practices during the next rotation