scholarly journals Tree Species Composition, Richness and Diversity in the Northern Guinea-Savanna Taraba State, Nigeria

Author(s):  
O. O. Sobola ◽  
D. O. Oke ◽  
A. G. Adedayo ◽  
J. A. Olusola

The study investigated tree species composition, diversity and abundance in the Guinea savanna ecosystem, Taraba State, Nigeria. Three transects with a distance of 500 m apart were used for the study. Four sample plots of 25 m x 25 m size were laid in alternate positions along each transect at 250 m intervals. Identification of trees/shrubs was carried out in the forest reserves. Biodiversity indices such as; Shannon-Wiener diversity index, Species evenness, Simpson’s diversity index, Margalef’s richness index and Menhinick’s diversity index, were estimated at the end of the study. The result of floristic diversity assessment showed that the two forest reserves were able to conserve trees/shrubs species diversity. This was reflected by the value obtained for diversity indices for the two land use types: Shannon- Weinner (3.29, 3.08), species evenness (0.47, 0.49), Simpson (0.95, 0.93), Margalef (6.83, 6.49), Minhinck’s index (2.09, 1.79) for Sonkpa and Jabwanje forest reserves respectively. The density of fruit trees/shrubs encountered in the two forest reserves were (279, 414) which accounted for (47% and 56%) of the total woody population in Sonkpa and Jabwanje forest reserves respectively. Among the prominent fruit trees/shrubs encountered were Nauclea latifolia, Gardenia aqualla, Annona senegalensis, Prosopis africana, Vitellaria paradoxa, Vitex doniana, Strychnos innocua.  However, the absence of Irvingia gabonensis and lower density of Afzelia africana was an indication that some important species are already going to extinction while others are endangered.  Hence, the State government should, intensify the management of savanna forest by controlling the intensity of tree harvesting, stop illegal felling and encourage enrichment planting. Genetic improvement through germplasm collection and propagation studies should be carried out on the under exploited edible fruit species for genetically improved cultivars production.

Author(s):  
Md. Humayain Kabir ◽  
Hillol Barua

Riparian vegetation has been depleting in the many river basins of Bangladesh. Consequently, this study assessed the tree species composition, structure and diversity of the midstream area of the Halda River in Bangladesh. Twenty two quadrats (20 × 20m in size) were sampled. A total of 414 individual tree stems of ≥10 cm DBH of 36 tree species belonging to 31 genera and 15 families were enumerated. Density, Basal area and volume of the tree species were measured. Different diversity indices, i.e. Shannon-Wienners Diversity Index, Simpson's Dominance Index, Pielou’s Species Evenness Index, Margalef's and Menhinick’s richness index were calculated. Fabaceae was the most represented family with nine species, followed by Moraceae, Meliaceae and Anacardiaceae. Density, basal area and volume of the trees were 470.45 stem/ha, 19.09m²/ha and 139.42m³/ha, respectively. Samanea saman was found to be dominant, showing a maximum IVI, followed by v, Mangifer aindica, Eucalyptus camaldulensis and Artocarpus heterophyllus. The findings of the study will be helpful for the posterior researchers in their research work and their future tree based planning programs and conservation. So it is recommended that greater emphasis should be taken to proper management and conservation against over extraction and illegal felling for the maintenance of existing tree species composition and density.


Author(s):  
E. T. Ikyaagba ◽  
J. I. Amonum ◽  
S. Okwoche

The role of sacred forest/sacred groves in the conservation of biodiversity is well recognised and documented. Despite the importance of sacred forests in conservation, data of flora species composition and diversity in many sacred forests still remain scanty.  The study was conducted to provide baseline data on tree species composition and diversity of Ipinu-Igede sacred forest with a view to promote the role of sacred forest in flora conservation in the area. Systematic sampling technique was adopted for the study. A base line transect of 2 km long was established and five (5) other transects 2 km long were laid at regular interval of 500 km apart. On each transect, 4 sampling plots of 50 mx50 m were established at a regular interval of 500m apart. Within the         50 m x50 m plots, trees with diameter at breast height (DBH)≥10 cm were identified and enumerated. Species Important Value Index (IVI), species richness, species evenness and species diversity were estimated. A total number of 50 tree species in 19 families were recorded. Cola gigantea was the most important tree species with IVI of 14.56, this was followed by Harungana madagascariensis with 13.14. Caesalpinioideae was the dominant family with 6 species, 48.15% of the families were represented by only one species. The species richness was D=9.436, Species Evenness was E´=0.7668 and species diversity was H=3.646. Thirty percent (30%) of the tree species were in the DBH class of 1-40cm indicating good regeneration status of the sacred forest. Acknowledgement of the traditional practices by scientists and other actors in natural resources conservation will help in promoting forest conservation.


2021 ◽  
Vol 15 (2) ◽  
pp. 147-161
Author(s):  
Hasya Hannani Ruziman ◽  
◽  
Faezah Pardi ◽  
◽  

Kuala Langat South Forest Reserve (KLSFR) was the main highlight when Selangor State Agriculture Corporation proposed to acquire the whole of KLSFR (about 6,908 ha) for the establishment of oil palm plantations. Many parties expressed their concern and opposed the plan as it would lead to the destruction of the forest and its biodiversity. As such, this study was aimed to determine the forest structure and tree species composition to conserve and sustainably manage the forest. Seven plots of 40 m x 20 m covering 0.56 ha were established randomly in KLSFR. All trees with 5 cm diameter breast height (DBH) and above were tagged, measured and identified. Voucher specimens were then taken for further verification purposes. The floristic composition of KLSFR consists of 335 individuals represented by 47 tree species from 21 families. Annonaceae, Guttiferaceae and Myrsticaceae were the most speciose families with five species recorded for each family. Goniothalamus malayanus and Koompassia malaccensis were considered to have absolute dominance at the study site with Important Value index of 14.73 % and 14.19 %, respectively. KLSFR recorded low Shannon-Weiner Diversity index of H’ = 2.85 (H’max = 3.81) and Margalef’s Richness Index with DMG = 7.91. Evenness (E) index of 0.75 portrayed that the tree species are almost equally abundant in the study area. Total trees biomass was estimated at 406.90 t/ha, represented by 349.61 t/ha of above ground biomass (AGB) and 57.29 t/ha of below ground biomass (BGB). The study indicated that KLSFR has uniform distribution of individuals with mixed species composition of trees. Tree distribution showed the pattern of De iocourt’s factor procedure (inverse J distribution) where number of tree decreases with the increase in diameter, representing the natural regeneration of the forest.


2008 ◽  
Vol 159 (4) ◽  
pp. 80-90 ◽  
Author(s):  
Bogdan Brzeziecki ◽  
Feliks Eugeniusz Bernadzki

The results of a long-term study on the natural forest dynamics of two forest communities on one sample plot within the Białowieża National Park in Poland are presented. The two investigated forest communities consist of the Pino-Quercetum and the Tilio-Carpinetum type with the major tree species Pinus sylvestris, Picea abies, Betula sp., Quercus robur, Tilia cordata and Carpinus betulus. The results reveal strong temporal dynamics of both forest communities since 1936 in terms of tree species composition and of general stand structure. The four major tree species Scots pine, birch, English oak and Norway spruce, which were dominant until 1936, have gradually been replaced by lime and hornbeam. At the same time, the analysis of structural parameters indicates a strong trend towards a homogenization of the vertical stand structure. Possible causes for these dynamics may be changes in sylviculture, climate change and atmospheric deposition. Based on the altered tree species composition it can be concluded that a simple ≪copying≫ (mimicking) of the processes taking place in natural forests may not guarantee the conservation of the multifunctional character of the respective forests.


2017 ◽  
Vol 47 (8) ◽  
pp. 997-1009 ◽  
Author(s):  
Katherine F. Crowley ◽  
Gary M. Lovett

As tree species composition in forests of the northeastern United States changes due to invasive forest pests, climate change, or other stressors, the extent to which forests will retain or release N from atmospheric deposition remains uncertain. We used a species-specific, dynamic forest ecosystem model (Spe-CN) to investigate how nitrate (NO3–) leaching may vary among stands dominated by different species, receiving varied atmospheric N inputs, or undergoing species change due to an invasive forest pest (emerald ash borer; EAB). In model simulations, NO3– leaching varied widely among stands dominated by 12 northeastern North American tree species. Nitrate leaching increased with N deposition or forest age, generally with greater magnitude for deciduous (except red oak) than coniferous species. Species with lowest baseline leaching rates (e.g., red spruce, eastern hemlock, red oak) showed threshold responses to N deposition. EAB effects on leaching depended on the species replacing white ash: after 100 years, predicted leaching increased 73% if sugar maple replaced ash but decreased 55% if red oak replaced ash. This analysis suggests that the effects of tree species change on NO3– leaching over time may be large and variable and should be incorporated into predictions of effects of N deposition on leaching from forested landscapes.


2006 ◽  
Vol 2 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Yong Kwon Lee ◽  
Don Koo Lee ◽  
Su‐Young Woo ◽  
Emmanuel Rodantes G. Abraham ◽  
Wilfredo M. Carandang ◽  
...  

2010 ◽  
Vol 16 (32) ◽  
pp. 387-392 ◽  
Author(s):  
Takahiro SHOJI ◽  
Hideyuki IDA ◽  
Toshikazu TSUCHIMOTO ◽  
Shigeo HOYANO

Author(s):  
Nuttaluck Khamyong ◽  
◽  
Prasit Wangpakapattanawong ◽  
Sutthathorn Chairuangsri ◽  
Angkhana Inta ◽  
...  

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