scholarly journals Forest Tree Composition: A Comparative Study of Timber Species in Bayelsa State Nigeria

2020 ◽  
Vol 2 (2) ◽  
pp. 64-73
Author(s):  
Samuel Olatokunbo Ihinmikaiye ◽  
Bernard Edache Ochekwu ◽  
Josiah Muonam Ikuli ◽  
Doris Akinjagunla Atinuke ◽  
Abel Zikenal Keresinbofa
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Ground Level ◽  
Diversity Indices ◽  
Forest Tree ◽  
Timber Species ◽  
Anthropogenic Pressure ◽  
Sample Plot ◽  
Management Options ◽  
Timber Tree

Measuring tree species diversity is critical for forest management, particularly where timber species suffer undue anthropogenic pressure. This study was carried out in Bayelsa State, Nigeria. A sample plot was systematically chosen from randomly selected communities in each of the three senatorial districts Bayelsa West (BW), Bayelsa East (BE) and Bayelsa Central (BC) of the State. Each sample plots measured 25 m x 25 m and all timber tree species that were at least six feet above ground level within each sample plot were identified, counted and measured. Fifty individual timbers were encountered in the sample plot at Ogobiri community in BW, fifty-two at Kolo 1 community in BE and fifty-six at Gbarain community in BC belonged to 18, 16 and 14 different families respectively. Families with the largest number of species in the plots were Gentianaceae and Meliaceae, and the highest diversity indices were recorded from BE senatorial district. Generally, the basal area of the sample plots increases with an increase in diameter at breast height. The forested zones were on flat terrain characterized by seasonal flood inundation, and the similarities of timber species in the plots occurred as (BW-BC)> (BW-BE)> (BC-BE). Also, four tree species Coelocaryon preussii, Sacoglottis gabonensis, Milicia excelsa and Triplochiton scleroxylon were identified as rare species, and management options that would ensure ad infinitum supply of timber species were proposed.

scholarly journals Stem Decay in Live Trees: Heartwood Hollows and Termites in Five Timber Species in Eastern Amazonia

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1087
Author(s):  
Ana Alice Eleuterio ◽  
Maria Aparecida de Jesus ◽  
Francis E. Putz
Keyword(s):  
Tree Species ◽  
Logistic Model ◽  
Basal Area ◽  
Abundant Species ◽  
Timber Species ◽  
Hollow Trees ◽  
Large Trees ◽  
Timber Tree ◽  
Species Characteristics ◽  
Components Analysis

Research Highlights: Tree size and wood characteristics influenced the susceptibility of five Amazonian timber tree species to heartwood decay and colonization by termites. Termites occurred in the heartwoods of 43% of the trees, with Coptotermes testaceus the most abundant species. Background and Objectives: Hollows and rotten cores in the stems of living trees have ecological and economic impacts in forests managed for timber. The decision on whether to cut or maintain hollow trees in such forests must account for the susceptibility of different tree species to decay. We investigated tree and wood characteristics of living trees of five commercial timber species in the eastern Amazon that influenced the likelihood of heartwood decay and the occurrence of termite nests inside the rotten cores. Materials and Methods: We used Pearson’s correlations and one-way analysis of variance (ANOVA) to explore relationships among tree basal area and hollow area. We used principal components analysis (PCA) to analyze the variation of wood anatomical traits, followed by a linear regression to explore the relationships between PCA scores, and heartwood hollow area. We used a logistic model to investigate if the probability the occurrence of colonies of C. testaceus inside tree cores varied with tree and species characteristics. Results: Heartwood hollow areas increased with stem basal area. Larger hollows were more likely to occur in species with higher vessel and ray densities, and smaller diameter vessels. Termites occurred in the hollows of 43% of the trees sampled, with C. testaceus the most common (76%). The probability of encountering termite nests of C. testaceus varied among tree species and was positively related to wood density. Conclusions: This study shows that given the increased likelihood of stem hollows and rotten cores in large trees, tree selection criteria in managed tropical forests should include maximum cutting sizes that vary with the susceptibility of different tree species to stem decay.

scholarly journals Predicting the distribution of forest tree species using topographic variables and vegetation index in eastern Acre, Brazil

2015 ◽  
Vol 45 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Symone Maria de Melo FIGUEIREDO ◽  
Eduardo Martins VENTICINQUE ◽  
Evandro Orfanó FIGUEIREDO ◽  
Evandro José Linhares FERREIRA
Keyword(s):  
Tree Species ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Elevation Gradient ◽  
Forest Tree ◽  
Entropy Method ◽  
Slope Aspect ◽  
Tropical Species ◽  
Ecological Requirements ◽  
Timber Tree

Species distribution modeling has relevant implications for the studies of biodiversity, decision making about conservation and knowledge about ecological requirements of the species. The aim of this study was to evaluate if the use of forest inventories can improve the estimation of occurrence probability, identify the limits of the potential distribution and habitat preference of a group of timber tree species. The environmental predictor variables were: elevation, slope, aspect, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). To estimate the distribution of species we used the maximum entropy method (Maxent). In comparison with a random distribution, using topographic variables and vegetation index as features, the Maxent method predicted with an average accuracy of 86% the geographical distribution of studied species. The altitude and NDVI were the most important variables. There were limitations to the interpolation of the models for non-sampled locations and that are outside of the elevation gradient associated with the occurrence data in approximately 7% of the basin area. Ceiba pentandra (samaúma), Castilla ulei (caucho) and Hura crepitans (assacu) is more likely to occur in nearby water course areas. Clarisia racemosa (guariúba), Amburana acreana (cerejeira), Aspidosperma macrocarpon (pereiro), Apuleia leiocarpa (cumaru cetim), Aspidosperma parvifolium (amarelão) and Astronium lecointei (aroeira) can also occur in upland forest and well drained soils. This modeling approach has potential for application on other tropical species still less studied, especially those that are under pressure from logging.

scholarly journals Structure and composition of trees in Mount Tilu Nature Reserve, West Java, Indonesia

2020 ◽  
Vol 21 (6) ◽  
Author(s):  
Tri Cahyanto ◽  
Muhammad Efendi ◽  
DIAN MUHAMAD RAMDAN
Keyword(s):  
Tree Species ◽  
Nature Reserve ◽  
Basal Area ◽  
Principal Component ◽  
Floristic Composition ◽  
Diversity Indices ◽  
Species Structure ◽  
West Java ◽  
Conservation Area ◽  
Regeneration Status

Abstract. Cahyanto T, Efendi M, Ramdan DM. 2020. Structure and composition of trees in Mount Tilu Nature Reserve, West Java, Indonesia. Biodiversitas 21: 2674-2680. An understanding of the structure and composition of stands in a conservation area is needed to support sustainable management strategy. However, this information in the Mount Tilu Nature Reserve, Bandung District, West Java area is still lacking. This research was aimed to analyze the structure and composition of tree species in the block of Malagembol forest, Mt. Tilu NR. Data collection was carried out through vegetation analysis using sampling plot method with size of 10x100 m2 at three-level altitudes of 1530 m, 1745 m, and 1950 m asl. Observation parameters included species names, number of individuals, and diameter at breast height (dbh). Data were analyzed to determine the floristic composition, species structure based on their diameter class, relative basal area, diversity indices, and analysis of the importance of the main components of trees species through Principal Component Analysis (PCA). A total of 32 tree species from 23 families was found in the observation plots which was dominated by Fagaceae, Lauraceae, and Myrtaceae families. Some pioneer plants covered the gap in vegetation due to minor disturbance and residual damage in the past. Nonetheless, the dominance of stands with small diameters indicated good regeneration status following such disturbance. Based on these findings, we recommend protecting the vegetation in Mt. Tilu NR by limiting community activities that can disturb the forest.

scholarly journals Sustainability of High-Value Timber Species in Mixed Conifer–Broadleaf Forest Managed under Selection System in Northern Japan

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 484
Author(s):  
Kyaw Thu Moe ◽  
Toshiaki Owari
Keyword(s):  
Mixed Forest ◽  
Basal Area ◽  
Basal Area Increment ◽  
Diameter Distribution ◽  
Permanent Plots ◽  
Timber Species ◽  
Selection System ◽  
Management Options ◽  
Species Proportions ◽  
Northern Japan

Understanding the sustainability of high-value timber species in managed forests provides useful information for the management of these species in the long-run. Using nearly 50 years of census data in long-term permanent plots, we investigated the sustainability of three high-value timber species—monarch birch (Betula maximowicziana Regel), castor aralia (Kalopanax septemlobus (Thunb.) Koidz), and Japanese oak (Quercus crispula Blume)—in cool-temperate mixed forest under a selection system in northern Japan. We used stocking, demographic parameters, and species proportions of these species as measures of sustainability. Results showed that the tree density and basal area of the three high-value timber species increased during the study period. Moreover, the basal area increment of these species showed an increasing trend across census periods. However, while no significant differences in the tree mortality of these species were observed, the numbers of in-growth fluctuated across census periods. Increasing trends in species proportions of monarch birch and Japanese oak were observed. Even though there were some fluctuations across census periods, especially in smaller diameter classes, diameter distribution curves of high-value timber species followed a reversed J-shaped pattern. The results revealed that the sustainability measures of high-value timber species can be achieved in forest stands managed under single-tree selection system. In addition, the results also indicated the changing structure and composition of the forest stand. The stocking and basal area increment of conifers decreased while those of broadleaves increased. The proportion of conifers decreased to 33.01% in 2008–2016 from 48.35% in 1968–1978. The results of this study would be useful for adapting silvicultural practices and harvesting practices as well as for simulating various silvicultural and management options for high-value timber species.

Structure of mixed pine and hardwood stands 12 years after various methods and intensities of site preparation in the Georgia Piedmont

1996 ◽  
Vol 26 (8) ◽  
pp. 1490-1500 ◽  
Author(s):  
Timothy B. Harrington ◽  
M. Boyd Edwards
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Low Cost ◽  
Basal Area ◽  
Diversity Indices ◽  
Site Preparation ◽  
Clear Cut ◽  
Clear Cutting ◽  
Georgia Piedmont ◽  
Compensatory Effect

In the Georgia Piedmont (U.S.A.), size, abundance, and species diversity of trees were quantified in a plantation of Pinustaeda L. 12 years after various methods and intensities of site preparation. In clear-cut only versus site-prepared plots, greater hardwood abundance (27% vs. 8% of the total basal area) and size (8.6 vs. 7.4 m in height) were associated with reduced pine volume (73 vs. 123 m3/ha) and increased Simpson and Shannon diversity indices. Tree-species richness was greater in plots where residual trees from clear-cutting had been removed with a chainsaw versus large machinery (10 vs. 7 species). With increasing site-preparation intensity, reductions in basal area of volunteer pines coincided with proportionate increases (R2 = 0.80) in basal area of planted pines. As a result of this compensatory effect, total volume of all pines varied little (122–134 m3/ha) among site-preparation intensities. Research results suggest that site-preparation treatments can be selected to facilitate the development of a variety of stand structures, including those that favor evenness (clear-cut only) or richness (manual cutting) of tree species, low-cost production of pine fiber (manual cutting), and stand uniformity for management of pine sawtimber (mechanical and herbicide).

scholarly journals Regeneration status and species diversity of major tree species under scientific forest management in Kapilbastu district, Nepal

2021 ◽  
Vol 31 (2) ◽  
pp. 26-39
Author(s):  
B. Aryal ◽  
S. Regmi ◽  
S. Timilsina
Keyword(s):  
Forest Management ◽  
Species Diversity ◽  
Tree Species ◽  
Diversity Indices ◽  
Management Technique ◽  
Timber Species ◽  
Natural Forests ◽  
Regeneration Status ◽  
The Simpsons ◽  
Regeneration Condition

In Nepal, scientific forest managementhas been practiced as an effective forest management technique to utilize forest resources sustainably. However, the program has faced many controversies such as intentional logging of only high-valued timber species like Shorearobusta. In addition, few believe this program is severely affecting the regeneration productivity and species diversity in the natural forests. In order to address these issues, we examinedthe regeneration condition and plant species diversity in the stands where scientific forest management operations were carried out. The data related to regeneration status and species diversity were collected using a systematic random sampling of the selected stands. Our results showed good regeneration conditions (Seedling >5000, Sapling>2000) in all the studied stands. The tree species community was dominated by S.robusta(Sal) followed by Schleicheraoleosa (Kusum) and Casia fistula (Rajbriksha). The value of diversity indices of different species varied significantly between felling series. The highest diversity was found in the second year felling series with the Simpsons Index of dominance value 0.6934 and the lowest species diversity was in the first year felling series with a value of 0.8448. It can be recommended that the regeneration felling practice has helped in promoting the regeneration condition and growth.  

scholarly journals Vegetation Dynamics in Treeline Ecotone of Langtang National Park, Central Nepal

1970 ◽  
Vol 11 ◽  
pp. 107-114 ◽  
Author(s):  
NP Gaire ◽  
YR Dhakal ◽  
HC Lekhak ◽  
DR Bhuju ◽  
SK Shah
Keyword(s):  
Tree Species ◽  
National Park ◽  
Basal Area ◽  
Anthropogenic Pressure ◽  
Climatic Warming ◽  
Seedling Density ◽  
Treeline Ecotone ◽  
Central Nepal ◽  
Abies Spectabilis ◽  
The Impact

A study was carried out at the treeline ecotone (3,730m-3,950m asl) of Langtang National Park in central Nepal with an aim to document the impact of climatic warming on ecological chracteristics. Three sampling sites were selected at Chaurikharka and Lauribina, where no serious anthropogenic pressure was noticed. The nearest meteorological station has records of climatic warming in recent years. Six tree species and three shrub species belonging to seven families were enumerated from the study plots. The average basal area for tree species was found to be 20.56 m2 per ha while average tree density was found to be 734 trees per ha with Abies spectabilis as dominant species. The mean DBH (diameter at breast height) of tree species was found to be 15.8 cm (max. 115.5cm). Density of dead trees accounted 2 no. per ha with basal area 0.195m2 per ha. Average sapling and seedling density of tree species per ha was observed to be 1,590 and 831 respectively. The average sapling and seedling density of A. spectabilis was 255 and 350 per ha respectively. Similarly, average shrub density (per ha) for the area was found to be 9,609 no/ha. The stand character showed that there was high level of recruitment of A. spectabilis in the recent years. The presence of sapling and seedling of A. spectabilis at higher altitude showing linear relationship with canopy coverage indicated prospects for a gradual and upward shift of A. spectabilis with increased temperature. Key words: Abies spectabilis; regeneration; climate change; DBH DOI: 10.3126/njst.v11i0.4132Nepal Journal of Science and Technology 11 (2010) 107-114

scholarly journals The Riparian Tree Species Composition and Diversity of the Midstream of Halda River in Chittagong, Bangladesh

2019 ◽  
pp. 1-14
Author(s):  
Md. Humayain Kabir ◽  
Hillol Barua
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Diversity Index ◽  
Research Work ◽  
Basal Area ◽  
Eucalyptus Camaldulensis ◽  
Diversity Indices ◽  
Individual Tree ◽  
Tree Species Composition ◽  
Area And Volume

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.

scholarly journals Vegetation composition and diversity of Piluwa micro-watershed in Tinjure-Milke region, east Nepal

1970 ◽  
Vol 2 (3) ◽  
pp. 29-32 ◽  
Author(s):  
Madan Koirala
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Diversity Indices ◽  
Total Density ◽  
Vegetation Composition ◽  
Regeneration Potential ◽  
Rhododendron Arboreum ◽  
Structure Degradation ◽  
Closed Canopy ◽  
Quercus Semecarpifolia

Comparative study of vegetation structure and composition of two forests at Tamafok (TF) and Madimulkharka (MM) villages in the Piluwa micro-watershed was undertaken. A total of 20 tree species were reported, with more species in the non-degraded TF forest than in the degraded MM forest. Rhododendron arboreum and Goldfussia penstemonoides were the dominant species in the TF forest, whereas Quercus semecarpifolia and Rhododendron arboreum were dominant in the MM forest. The total density of trees in the TF forest (756 ha-1) was higher than that at MM (346 ha-1). Similarly, tree basal area in the TF forest (69.8 m2 ha-1) was greater than at MM (56.9 m2 ha-1). Shrub density was also higher in the TF forest than at MM. Diversity indices for both trees (2.61) and shrubs (0.915) in the TF forest showed higher values in comparison to MM (2.4, 0.854). Concentration of dominance of the tree species was stronger in the MM forest (0.266) as compared to TF (0.258). The regeneration potential was higher in the degraded MM forest than in the relatively undisturbed TF forest. Seedling-sapling density was lower in undisturbed and mature forest which had closed canopy. Key words: Forest structure, degradation, species richness, dominance Himalayan Journal of Sciences 2(3): 29-32, 2004

scholarly journals Growth rates of valuable tree species in secondary tropical montane cloud forests in Mexico: influence of tree size, crown position and competition

2019 ◽  
Vol 25 (3) ◽  
Author(s):  
Magdaleno Mendoza-Hernández ◽  
Patricia Gerez-Fernández ◽  
Silvia Purata-Velarde ◽  
Tarin Toledo-Aceves
Keyword(s):  
Growth Rates ◽  
Tree Species ◽  
Basal Area ◽  
Selective Logging ◽  
Tree Size ◽  
Diameter Growth ◽  
Timber Species ◽  
Cloud Forests ◽  
Negative Effect ◽  
Tropical Montane Cloud Forests

Tropical montane cloud forests (TMCF) are under severe threat from deforestation, fragmentation and degradation. Several tree species are harvested and commercialized by local communities through unplanned selective logging. Lack of information regarding the growth rates of the most economically valuable timber species hampers the design of effective sustainable management schemes for TMCF. The objective of this study was to determine the diameter growth rates and evaluate the influence of tree size, crown class and neighbouring tree basal area on the growth of common and valuable TMCF timber species. Annual diameter growth was measured during two years in 60 trees (10 to 45 cm in diameter at breast height; dbh) each of Alnus acuminata, Liquidambar styraciflua and Quercus xalapensis, located in two unmanaged secondary TMCF sites in Veracruz, Mexico. High diameter growth rates (centimeter per year [cm yr-1]; mean ± SE) were recorded in the three species; the highest was recorded in A. acuminata (1.62 cm yr-1 ± 0.08 cm yr-1), followed by Q. xalapensis (0.91 cm yr-1 ± 0.07 cm yr-1) and L. styraciflua (0.71 cm yr-1 ± 0.08 cm yr-1). Diameter growth rate was inversely related to the basal area of the neighbouring trees, indicating a negative effect of competition in the three species. Dominant trees had higher growth rates than supressed trees in the three species. The high growth rates recorded in forests with no previous management and the negative effect of basal area of neighbouring trees support the potential for silvicultural management in secondary TMCF.

Sign in / Sign up

Export Citation Format

Share Document