ONYEKWELU JONATHAN C. picture
ONYEKWELU JONATHAN C.

Publication

Publisher:
 Forstliche Forschungsberichte 219, Munich, Germany, Pp 132 - 148
Publication Type:
 Others
Publication Title:
 Significance Of Traditional Forest Management System To Biodiversity Conservation And Ecosystem Services Provision: Case Study Of Osun-Osogbo Sacred Grove, Nigeria.
Publication Authors:
 Onyekwelu, J.C.
Year Published:
 2021
Abstract:
This study investigated and compared the biodiversity status of sacred grove, primary and degraded forests. Osun-Osogbo sacred grove, two primary and two degraded forests were involved. Osun-Osogbo sacred grove had the highest species richness, Shannon-Wiener diversity index, regeneration richness and high species evenness. The better diversity indices of Osun-Osogbo grove compared to those of primary and degraded forests are indications of its importance in biodiversity conservation. The preservation of the sacred grove was secured through belief and fear of deity, preservation of culture, place of worship, etc. Some ecosystem services provided by sacred grove include: healing, protection and peace, tourism, employment provision, spiritual worship, revenue generation, etc. 
Publisher:
 Journal Of Agriculture And Forestry Sciences, 8(3), 1-9.
Publication Type:
 Journal
Publication Title:
 Growth Characteristics And Trends Of Hevea Brasiliensis Muell. Arg. Plantations In Rainforest Ecosystem Of Edo State. Research
Publication Authors:
 Samuel, O.G., Onyekwelu, J.C. And Omokhafe, K.O.
Year Published:
 2021
Abstract:
The climate change problem is compounded by the tree-deficit situation in the world due to deforestation and forest degradation and other land-use changes. The objective of this study was to examine growth characteristics of Hevea brasiliensis plantations of different ages. Using simple random sampling method, five age series were selected for enumeration. Four temporary sample plots of 20 m x 20 m were randomly selected per hectare, resulting to a total of 20 sampling plots for this study. Within each sample plot; diameter at breast height (dbh), and total height of all individual trees were measured; while diameters at the base, middle and top of two mean trees were measured. Simple linear regression equations were fitted to the growth data to test the relationships between pairs of growth parameters. The results showed that stand mean Dbh ranged from 7.7 cm to 31.2 cm, stand basal area ranged from 1.8 m2/ha to 26.1 m2/h, while stand volume ranged from 10.6 m3/ha to 282.7 m3/ha. Hevea brasiliensis trees in this study showed evidence of fast growth rate. the mean stand growth parameters (Dbh, basal area, height and volume) showed strong and positive linear relationships with stand age. For individual trees, volume was linearly related to Dbh (R2 = 0.78) and exponentially related to total height (R2 = 0.92). Effective management and sustainable development of H. brasiliensis plantations are strongly recommended for higher yields and environmental benefits in Nigeria. 
Publisher:
 Burleigh Dodds Science Publishing, Cambridge, UK.
Publication Type:
 Technical Report
Publication Title:
 Sustainable Management Of Tropical Plantation Forests. In: Blaser, J. And Hardcastle, P.D. (Eds), Achieving Sustainable Management Of Tropical Forests.
Publication Authors:
 Onyekwelu, J.C.
Year Published:
 2020
Abstract:
Nil 
Publisher:
 Journal Of Forestry Research And Management. 17(2).83-92;
Publication Type:
 Journal
Publication Title:
 Biomass And Carbon Stock Assessment Of A Tropical Rain Forest Ecosystem In Nigeria
Publication Authors:
 Oke, O.S., Akindele, S.O. And Onyekwelu, J.C.
Year Published:
 2020
Abstract:
Okomu National Park is the smallest National Park in Nigeria. It is managed mainly for wildlife conservation and has a lot of tree biodiversity. The potential of its forest for carbon sequestration has not been explored, therefore this study was undertaken to assess above- ground and below-ground biomass of the forest. To achieve this, line transect sampling method was used in the collection of field data. A total of fourteen (14) 50 m X 50 m temporary sample plots were laid. Trees with diameter at breast height (dbh) greater or equal to 20 cm were enumerated within the 50 m X 50 m plots. Relevant tree variables were measured and core samples were obtained from the trees. Tree variables measured include: diameter at breast height (dbh); diameter at the base (db); diameter at the middle (dm); diameter at the top (dt); total height (h); and merchantable height (mht). The core samples were dried in the laboratory until a constant weight was attained and analyses were carried out on data collected for the biomass and carbon estimation. The result obtained showed that the average above-ground biomass (ABG) was 268,023.76 kg/ha while the average for below-ground biomass (BGB) was 67,005.94 kg/ha. Carbon estimated for AGB was 134.01 tons/ha while that of BGB was 33.50 tons/ha. The total carbon estimated for AGB and BGB was 3,387, 820 tons. This indicates that carbon stock of the National Park is highly significant, this can be of great economic value if properly harnessed. 
Publisher:
 Urban Ecosystem, 23:957–970.
Publication Type:
 Journal
Publication Title:
 Tree Species Diversity, Volume Yield, Biomass And Carbon Sequestration In Urban Forests In Two Nigerian Cities.
Publication Authors:
 Agbelade, A.D. And Onyekwelu, J.C.
Year Published:
 2020
Abstract:
Urban forests contribute greatly to the conservation of biodiversity and are able to store carbon in the same way as other forest ecosystems. This research investigated the diversity, volume yield, biomass and carbon sequestration of tree species in urban forests in two Nigerian cities (Port Harcourt and Ilorin) selected using simple random sampling. In Nigeria there is no record of quantitative assessment of carbon sequestration in urban forests. Biodiversity and growth data were obtained from about 20% of the built-up areas of the two cities. Non-destructive approach was used for above ground biomass estimation. Biomass data was used to quantify carbon stock to estimate the amount of carbon sequestrated by the urban forests in the two cities. The results revealed a total of 746 individual trees distributed among 37 species and 19 families in Port Harcourt, while 556 individual trees distributed among 46 species and 18 families in Ilorin urban forest. Shannon-Wiener diversity index for Port Harcourt was 3.39 while that of Ilorin was 3.61. The total carbon stored by the urban forest of Port Harcourt was estimated at 67,979.08 tons and Ilorin urban forest carbon stored was estimated at 91,512.49 tons. The average carbon density of the urban forest of Port Harcourt was estimated at 136.15 tons/ha and 7.82 tons/ha was estimated for Ilorin urban forest. Tree species diversity has greater impact on biomass accumulation which determines carbon sequestration and mitigation of harsh climatic conditions. Selection and planting the right species as avenue trees, building parks and gardens, urban landscaping can improve urban forest carbon sequestration and producing other urban forest ecosystem functions. 
Publisher:
 Proceedings Of 7th NSCB Biodiversity Conference, October 2020, Pp, 20 - 33.
Publication Type:
 Conferenceproceeding
Publication Title:
 Distribution, Species Diversity And Conservation Potentials Of Sacred Groves In Southwestern, Nigeria.
Publication Authors:
 Onyekwelu, J.C., Tolorunju, M.S., Agbelade, A.D., Lawal, A., Stimm, B. And Mosandl, R.
Year Published:
 2020
Abstract:
This study examined the distribution, species diversity and conservation potentials of sacred groves in southwestern, Nigeria. Four sacred groves were selected (Osun-Osogbo, Igbo-Olodumare, Idanre hills and Ogun Onire sacred groves), from three states in south west, Nigeria. Data were collected from 32 temporary sample plots of 20 m x 40 m established across the four sacred groves. A total of 18 sacred groves were located in five states, which was not considered exhaustive due to some constraints. In these four sacred groves 34 families were enumerated at the overstory layer of the four sacred groves, with 24, 23, 19 and 19 families occurring in Ogun Onire, Osun Osogbo, Igbo Olodumare and Idanre hills sacred groves, respectively. Species richness varied from 32 to 58, with Ogun Onire having a significantly higher number of species than other sacred groves. Tree density in the four sacred groves ranged from 309 ha-1 to 417ha-1. Shannon-Wiener diversity index for overstory species ranged from 3.47 to 4.06 and was significantly different between the sacred groves, with Igbo Olodumare and Ogun Onire having the lowest and highest values, respectively. The understory species richness at Ogun Onire (46), Idanre Hills (37), Osun Osogbo (34) and Igbo Olodumare (23) sacred groves was generally lower than overstory species richness. Also, the understory layer had lower Shannon-Wiener diversity index (range: 2.04 to 3.30) compared to the overstory layer in all sacred groves. The implication of the results is that sacred groves have high potentials for biodiversity conservation. 
Publisher:
 Proceeding Of Virtual 3rd CFA Conference Of The Commonwealth And Forestry Association, Nigeria, 2 - 3 Dec., 2020,113-121 Pp
Publication Type:
 Conferenceproceeding
Publication Title:
 Dead Organic Matter Carbon Assessment In Okomu National Park In Forest Ecosystem Potentials In Nigeria: Opportunities For Green Economy In The 21st Century.
Publication Authors:
 Oke, O.S., Akindele S.O. And Onyekwelu J.C.
Year Published:
 2020
Abstract:
Nil 
Publisher:
 Enzyklopädie Der Holzgewächse – 72. Erg. Lfg. 01/19, 16pp
Publication Type:
 Monograph
Publication Title:
 Garcinia Kola. HECKEL. In: Schütt, P.; Weisgerber, H.; Lang, U.; Roloff, A.; Stimm, B. (eds.).
Publication Authors:
 Onyekwelu, J.C. And Stimm, B.
Year Published:
 2019
Abstract:
There are more than 600 species in the genus Garcinia throughout the tropics. Most of the species within this genus are upperstorey tree species, with some of them large enough to the extent that they are useful for timber. However, only 16 of these species are found in West Africa. Garcinia kola (Heckel) and its relatives, including G. livingstonei, G. gnetoides, G. staudtii, G. smeathemannii, G. ovalivolia, G. brevipediellata and G. mannii, are found in Nigeria as well as across the humid lowland plains of West Africa. Among all these Garcinia species, G. kola is by far the most popular. G. kola Heckel, popularly called bitter kola, is a very important edible fruit and medicinal tree species distributed in moist tropical forests of West and Central Africa. It is also known as false kola (mainly due to the absence of the stimulants that characterise the kola nut seeds) and male kola (due to its reported aphrodisiac properties). G. kola has been referred to as ‘wonder plant’ because almost every part of the tree has been found to be of medicinal importance. Thus, the species is a multi?purpose tree, similar to kola nuts (Cola nitida). 
Publisher:
 Simplicity Press, Akure, Nigeria, Pp 277–298.
Publication Type:
 Others
Publication Title:
 Harnessing The Riches And Diversity Of Tropical Rainforest Ecosystems For Poverty Alleviation, Food And Health Security. In: Osundahunsi, O.F. (ed), Roadmap To Improve Livelihoods In Africa.
Publication Authors:
 Onyekwelu, J.C.
Year Published:
 2018
Abstract:
Though tropical forests account for about 7% of the world’s land surface and only 2% of the surface of the globe, they accommodate between 60% and 70% of all animal and plant species in world ecosystems and have the potential to provide all that is needed for human livelihood and survival. Globally, about 1.6 billion people depend on the forest to some extent, 350 million people depend on the forest to a high degree while 60 million people depend almost entirely on the forest for food and nutrition, healthcare delivery, employment and economic empowerment. In addition, the forest ecosystem provides a number of ecosystem services such as biodiversity conservation, maintenance of local climate, soil protection, prevention of soil erosion, protection of water catchment, provision of scenic beauty, educational value, etc. The high biological diversity of tropical rainforest ecosystems has conferred on them a great potential to alleviate rural poverty, provide food and medicine to the people among others. This paper discusses the potentials of tropical rainforest ecosystems to contribute to food security, health security and poverty alleviation. Some measures necessary to harness these potentials of tropical rainforest were identified and briefly discussed. 
Publisher:
 Wiley Enzyklopädie Der Holzgewächse – 71. Erg. Lfg. 02/18, 16pp
Publication Type:
 Monograph
Publication Title:
 Blighia Sapida. K.D. Koenig. In: Schütt, P.; Weisgerber, H.; Lang, U.; Roloff, A.; Stimm, B. (eds.).
Publication Authors:
 Onyekwelu, J.C. And Stimm, B.
Year Published:
 2018
Abstract:
The ackee fruit is a major food source in the island of Jamaica, where it can be seen growing extensively in house compounds, on roadsides, in fence rows, and on submarginal lands. There are two distinct varieties of ackee fruit found in Jamaica: butter or soft ackee with a soft yellow aril, and cheese or hard ackee with a hard cream colored aril. The phytochemical constituents present in the ripe arils of the ackee fruit could prove nutritionally beneficial when consumed. The ripe aril is consumed after the seed and funiculus are carefully removed from the pericarp. The presence of phenols, tannins, saponins, glycosides, minerals, and vitamin C could impact human health positively. Ackee arils provide a rich source of omega?9 fatty acids; however, omega?6 and omega?3 fatty acids are present in lower concentrations. These unsaturated fatty acids offer tremendous potential in reducing the risk of chronic illnesses such as coronary heart diseases and cancers.