Pattern in a derived savanna in Nigeria

1991 ◽  
Vol 7 (4) ◽  
pp. 491-502 ◽  
Author(s):  
P. Greig-Smith
Keyword(s):  
Analysis Of Variance ◽  
Block Size ◽  
Basal Area ◽  
Species Density ◽  
Forest Reserve ◽  
South West ◽  
Derived Savanna ◽  
Woody Growth

ABSTRACTAll woody growth was enumerated in three transects, each 960 m x 20 m, in derived savanna in the Olokemeji Forest Reserve in south-west Nigeria. The data for species density, species basal area and stem girth classes were analysed by nested-block analysis of variance and covariance. The use of ‘total covariance’, the sum of all covariances at a block size, contributes to understanding of the pattern present.Three scales of pattern were evident. Patchiness at 160–320 m is interpreted as a response to soil differences or to the pattern of previous farming, which may itself have been determined by soil differences. Patchiness at 20–40 m is attributable to varying intensity of burning. At the smallest scale, of 10 m, there is evidence of regularity of distribution resulting from interference between individuals, possibly due to competition for water.

Monitoring natural stand change in the forest reserve of Liedekerke, Flanders (Belgium)

1999 ◽  
Vol 64 ◽  
Author(s):  
D. Van den Meersschaut ◽  
B. De Cuyper ◽  
K. Vandekerkhove ◽  
N. Lust
Keyword(s):  
Species Composition ◽  
Castanea Sativa ◽  
Basal Area ◽  
Alnus Glutinosa ◽  
Indigenous Species ◽  
Stem Number ◽  
Mature Trees ◽  
Forest Reserve ◽  
Natural Stand ◽  
Sweet Chestnut

Natural  stand changes in the forest reserve of Liedekerke were analysed during the  period    1986-1996, using a permanent grid of circular plots. The monitoring  concentrated on natural    changes in species composition, using stem number and basal area as  indicators, and changes    in spatial distribution and colonization capacities of trees and shrubs,  with special interest in the    competition between exotic and indigenous species. After only a decade of  monitoring important    natural changes in the woody layer were detected. The pioneer forest is  gradually maturing    through self-thinning processes and shifts in species composition. The  overall stem number    decreased with 33.6%, while the basal area increased with 20.9%. Birch (Betula pendula/    pubescens) and indigenous oak (Quercus robur/petraea) remained  dominant. More tolerant    exotic species, like red oak (Quercus rubra) and sweet chestnut (Castanea  sativa), are slowly    increasing their share in the species composition and expanding their  range. Pioneer species on    the other hand, like aspen (Populus tremula), willow (Salix  capreaicinerealaurita), alder buckthorn    (Frangula alnus) and  common (Alnus glutinosa)  and grey alder (A. incana),  strongly declined.    Black cherry (Prunus serotina) seems to be slowly invading the forest due to its  massive    natural regeneration. Strong competition may be expected especially from  rowan ash (Sorbus    aucuparia), which showed similar regeneration  and colonization capacities. Elder (Sambucus    nigra) dramatically extented its range, though  its share remains marginal. Beech remained absent    most probably due to the lack of mature trees in the vacinity of the  forest. Finally this    change detection allowed that general predictions could be made on the  future natural development    and composition of this forest reserve, which could serve forest management  decisions.

Effects of tree species heterogeneity on leaf fall in primary and logged dipterocarp forest in the Ulu Segama Forest Reserve, Sabah, Malaysia

1994 ◽  
Vol 10 (1) ◽  
pp. 1-26 ◽  
Author(s):  
T. B. A. Burghouts ◽  
E. J. F. Campbell ◽  
P. J. Kolderman
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Primary Forest ◽  
Forest Plot ◽  
Pioneer Species ◽  
Leaf Fall ◽  
Forest Reserve ◽  
Dipterocarp Forest ◽  
Canopy Trees ◽  
Logged Forest

ABSTRACTEffects of tree species heterogeneity on leaf fall were studied in a primary (4 ha) and in a selectively logged forest plot (2.5 ha) in the Ulu Segama Forest Reserve, Sabah, Malaysia, from April 1988 to December 1989. Leaf fall was collected at 30 sampling points in each plot, and identified to species.Dipterocarpaceae, Euphorbiaceae, Lauraceae, Fagaceae and Meliaceae are important tree families in both plots with regard to their contribution to total basal area, tree density and annual leaf fall. The total number of tree species was higher in the primary forest plot (267) than in the logged forest plot (218), although the number of climber species was higher in the logged forest (44) than in the primary forest plot (33). The overlap in species composition between the two forest plots was relatively small (49%) compared with that in family composition (88%).In the primary forest plot, the Dipterocarpaceae contributed 29% of the total basal area and 34% of the annual leaf fall. In the logged forest plot these contributions were much lower, 11% and 15%. The contribution to annual leaf fall made by climbers and pioneer trees was higher in the logged forest plot (34%) than in the primary forest plot (8%).In the primary forest plot, leaf fall was dominated My large emergent and main canopy trees, mainly dipterocarps, and occurred as regular large peaks. In the logged forest leaf fall was dominated by climbers and many, relatively small trees of pioneer species, such as Macaranga hypoleuca, and was more evenly distributed in time.

scholarly journals Floristic Composition and Structure in Relation to Elevation in the Togo Plateau Forest Reserve in Ghana

2020 ◽  
Vol 1 (6) ◽  
Author(s):  
Gilchrist K. Faith Dogor ◽  
Emmanuel Acquah ◽  
Alexander K. Anning
Keyword(s):  
Elevation Gradient ◽  
Basal Area ◽  
Floristic Composition ◽  
Species Identity ◽  
R Software ◽  
Elevation Gradients ◽  
Forest Reserve ◽  
Composition And Structure ◽  
Special Scientific ◽  
Geographical Locations

Plateau ecosystems are of special scientific and conservation interests as they harbour rich plant diversity and exhibit considerable spatial variability along elevation gradients. In this study, variations in floristic composition and structure in relation to elevation were studied in six-fringed communities Hohoe (HH), Alavanyo (AL), Santrokofi (SA), Akpafu (AK), Bowuri (BO), and Nkonya (NK) of the Togo Plateau Forest Reserve in Ghana to better provide explicit and effective management of this ecological hotspot. A total of 180 plots (each measuring 25m × 25m) were demarcated across the six communities for sampling of trees (DBH measured at 1.3 m above ground ≥10 cm). Smaller nested plots, measuring 5m × 5m and 1m × 1m were used for sampling saplings (DBH < 10 cm, height > 1.5 m) and seedlings (DBH < 3 cm, height < 1.5 m), respectively. Species identity and abundance and elevation were recorded for each plot. Relationships of elevation gradients with vegetation attributes were analysed using simple linear regression and R software package. A total of 281 plant species (164 trees, 60 saplings and 57 seedlings) belonging to 66 families were recorded in the study. Leguminosae, Apocynaceae and Euphorbiaceae were the most dominant families across and along the elevation gradient. The average basal area of trees was calculated as 44.72 m2/ha and varied across the six communities (ranged from 57.10 m2/ha at BO to 33.10 m2/ha at AL) whereas the Shannon-Weiner Index (H’) averaged as 3.99 and varied across the six communities (ranged from4.14 m2/ha at BO to 3.89m2/ha at AL) and evenness index averaged as 0.96 (ranged from1.00at BO to 0.92 at AL). The saplings and seedlings also follow a similar pattern of composition and structure. The geographical locations of the study communities which somehow correspond with different elevations to the plateau (i.e., BO, NK occur in lower elevations, SA, AL in mid elevations and HH, AL in higher elevations) has been identified as the drivers of the composition and structure across the communities on the landscape. The most important trees listed in the study were C. pentandra, A. zygia, and T. superba. The saplings were A. camerunensis, M. puberula and C. ferruginea. The seedlings were C. odorata, P. hirsuta and C. affer. The most important tree species listed were distributed along a broad range of elevation. Results obtained revealed high biodiversity of the plateau. These findings may lead to a better understanding of the composition and structure of several plateau ecosystems found in Ghana and elsewhere.

scholarly journals Evaluation of Soil Physicochemical Properties, Soil Seed Bank and Species Density of Five Plant Communities in Awka Anambra State

2021 ◽  
pp. 45-54
Author(s):  
Archy O. Nora ◽  
U. K. Ekwealor ◽  
I. E. Mbaekwe ◽  
Izundu, I. Alex ◽  
C. F. Iroka
Keyword(s):  
Physicochemical Properties ◽  
Analysis Of Variance ◽  
Seed Bank ◽  
Species Density ◽  
Ground Vegetation ◽  
Lowland Forest ◽  
Abandoned Farmland ◽  
Tropical Lowland ◽  
Tropical Lowland Forest ◽  
Experimental Plots

The research study investigated the physicochemical properties of the soil in five different locations around Nnamdi Azikiwe University Awka campus for their above ground and seed bank status with regards to their germination rate and species density. The study areas were located at Cattle grazed field at gariki Amansea, abandoned farmland near Chisco Transportation and Engineering workshop, frequently mowed lawn at Unizik e-library, a Savanna woodland behind the banking plaza Unizik  and tropical lowland forest at Botanical garden Unizik. The seed bank investigation was conducted from September 2016 to March, 2017. Analysis of variance was used to test significant differences between seed bank densities among experimental plots at different soil horizons. The soil physiochemical parameters among the experimental plots were also analyzed by one-way analysis of variance. Significant differences were tested at P= 0.05 at 95% confidence intervals. Results revealed the highest value for above ground species was found in tropical lowland forest (53.67±6.11) while the lowest was in cattle grazed field (8.00±0.82). Meanwhile the highest value for seed bank was in the frequently mowed lawn Unizik e-library (93.00±18.00) and the lowest was in the forest (6.50±4.95). The comparison of the two groups using T-test revealed that there was a significant difference between the above ground and seed bank values of the tropical lowland forest P=0.003 and also between the above ground and seed bank values of the frequently moved lawn, Unzik e-library P=0.001. More so, the Savanna above ground values and seed bank species value were not significant at P=0.006, as well as cattle grazed field (8.00 ± 0.82) and (50.00± 19.31) at P=0.006. Also, the Savanna plot comparison of above ground (44.50±3.54) and the seed bank (14.00±5.20) revealed significant differences between the two groups at P=0.006. Electrical conductivity was highest in the cattle grazed field (40.00+1.08) and the highest pH value was found in the Unizik e-library (6.19+0.22). Sorensen’s coefficient index revealed the highest similarity between above ground and seed bank species occurred in the cattle-grazed field followed by the frequently mowed lawn Unizik e-library (0.196), then the abandoned farmland (0.074), the Savanna (0.060) and the forest (0.025) respectively. Since the similarity is measured between 0 and 1, it means therefore that there is a weak similarity (0.276) between above ground vegetation and the seed bank in the cattle grazed field while the frequently mowed lawn (0.196) above ground similarity with seed bank was very weak. There is no similarity (0.025) between the above ground vegetation and the seed bank in the tropical forest. This seed bank investigation showed that the number of plant species in the seed bank does not reflect the total number of species in the above ground and the soil properties have an impact on the species density of the areas.

scholarly journals Geo-spatial Assessment of Land Use/Land Cover (LU/LC) Dynamics in Akoko South West Local Government, Ondo State, Nigeria

2021 ◽  
pp. 46-54
Author(s):  
Dada Ibilewa ◽  
Mustapha Aliyu ◽  
Usman O. Alalu ◽  
Taiwo Hassan Abdulrasheed
Keyword(s):  
Land Use ◽  
Local Government ◽  
Land Cover ◽  
Landsat Images ◽  
Rock Outcrops ◽  
Forest Reserve ◽  
Spatial Assessment ◽  
South West ◽  
Moderate Change ◽  
Microsoft Office

Geo-spatial assessment of land use/cover dynamics in Akoko South West Local Government was instigated to bridge the knowledge gap created by data deficiency on the nature, scope and magnitude of land use/cover change in the area. This was done through the analysis of Landsat images of three epochs from 2000 through 2010 to 2020. The processing of the satellite images was done in ArcGIS 10.8 while the analysis and 2030 projection was done in Microsoft office excel using the result from the analysis. QGIS was used to remove the scan lines error on the 2010 image. The result showed increasing built-up area, reducing vegetation and farmlands and diminishing rock outcrops. The changes vary among the different classification characteristics. The increasing change in the second epoch was higher in built up areas while rock outcrops increased in the first epoch. Farmland and vegetation were on reducing trend throughout the study period. However, the moderate change observed in the second epoch for the two land cover classes were not as significant as the first epoch. Government policies on forest reserve should strictly be adhered to in order to preserve the vegetation in the area. People of the area should be advised to diversify their economy in order to avoid total dependence on the forest reserve.

scholarly journals Assessment of Timber Resource Exploitation in Shasha Forest Reserve, Osun State, Nigeria: Implication for Sustainable Forestry

2021 ◽  
Vol 25 (8) ◽  
pp. 1355-1359
Author(s):  
B.L. Olajiire-Ajayi ◽  
D.A. Adenuga ◽  
B.T. Olatunji ◽  
O.O. Abegunrin ◽  
A.S. Adebayo ◽  
...  
Keyword(s):  
Basal Area ◽  
Sustainable Forestry ◽  
High Rate ◽  
Resource Exploitation ◽  
Forest Reserve ◽  
Exploitation Rate ◽  
Monitoring And Enforcement ◽  
Ricinodendron Heudelotii ◽  
Area And Volume

Records on rate of timber exploitation are very essential for sustainable forestry. They help in managing the forest sustainably. Therefore, the study collected and analysed data on rate of timber exploitation in Shasha forest reserve in Osun state. Logs arranged and set to be taken out of the forest were identified and measured every Monday between December, 2017 and June, 2018 for twenty-eight (28) weeks. The species and families of logs encountered were identified. A total of 13,944 logs were assessed. Fifteen (15) families belonging to twenty-one (21) species of logs were identified. Result revealed that Sterculiaceae family with five species was the most exploited. Ricinodendron heudelotti has the highest number of exploited logs with overall frequency of 27.71%. Ricinodendron heudelotti had the highest basal area and volume with values of 18018776.71cm² and 113289.36cm³ respectively. The study concludes that the population of Ricinodendron heudelotii tree was high in Shasha forest which made it available for extraction at high rate. The study recommends strict monitoring and enforcement of sustainable forestry laws with regular inventory and up-to-date inventory of timber exploitation rate from the reserve.

scholarly journals Non-Timber Forest Products and Climate Change Adaptation / Forest Dependent Communities In Bamboko Forest Reserve, South West Region Of Cameroon

2020 ◽  
Author(s):  
Tieminie Robinson Nghogekeh ◽  
Chia Eugene Loh ◽  
Tieguhong Julius Chupezi ◽  
Nghobuoche Frankline Mayiadieh ◽  
Piabuo Serge Mandiefe ◽  
...  
Keyword(s):  
Climate Change ◽  
Forest Products ◽  
Safety Net ◽  
Crop Failure ◽  
Forest Reserve ◽  
West Region ◽  
South West ◽  
Non Timber Forest Products ◽  
Current Change ◽  
South West Region

Abstract Background: This study to assess the role of Non-timber forest products was conducted to forest dependent communities around Bamkoko Forest Reserve in the South West Region of Cameroon as a strategy to cope with the impacts of climate change. Methods: Data were collected through household questionnaires, participatory rural appraisal techniques, transect walk and direct field observations. Results: A total of 16 plants species were identified to be harvested by residents around Bamkoko Forest Reserve as None Timber Forest Products. The majority of the respondents (88%) perceived that there has been a change in the climate patterns due to increased temperatures and unpredictable rainfalls. Eru was found to be the most affected livelihood activity (55%) by climate change around Bamboko Forest Reserve. Communities living around Bamboko Forest Reserve were found to use more than one strategy to cope with the adverse effects of climate change. Conclusion: The study concluded that NTFPs still play a safety net role to assist communities in adverse situation such as crop failure under the current change in climate. The need to emphasis sustainable harvesting, improve processing and access to NTFPs markets is crucial.

Fire favours expansion of bamboo-dominated forests in the south-west Amazon

2010 ◽  
Vol 27 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Maira Smith ◽  
Bruce Walker Nelson
Keyword(s):  
Forest Fires ◽  
Basal Area ◽  
Natural Disturbance ◽  
Ground Level ◽  
Control Area ◽  
The South ◽  
South West ◽  
The Face ◽  
Woody Bamboos ◽  
Two Measures

Abstract:Forests dominated by semi-scandent woody bamboos of the genus Guadua cover about 165 000 km2 of the south-west Amazon. Because many woody bamboo species are favoured by disturbance some authors have inferred this landscape to be a consequence of indigenous or natural disturbance. As seen in satellite images, the rounded edges of some bamboo-dominated forests indicate expansion into surrounding forest. These edges are unrelated to topography and resemble the borders of ground fires in unlogged Amazon forests, suggesting that bamboo may have been favoured by past fires. We studied the recovery of Guadua sarcocarpa and its competitors in the face of simulated fire by cutting all plant stems at ground level in ten 100-m2 plots, compared with ten control plots, and by burning a 2500-m2 plot. In the clear-cuts, bamboos recovered more successfully than did palms and dicots, by two measures: biomass accumulated and per cent recovery of pre-disturbance biomass. Resprouted bamboo attained higher stem densities than in control sites at 11 mo. In the burn plot, bamboo basal area recovered to pre-burn levels after 2 y and approached that of an undisturbed control area after 3 y. Though other natural disturbances are relevant, we conclude that forest fires should favour the spread and dominance of Guadua species in the south-west Amazon.

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