• Journal of Forest and Environmental Science
• /
• v.30 no.2
• /
• pp.233-242
• /
• 2014

Estimating above-ground biomass is important in establishing an applicable methodology of Measurement, Reporting and Verification (MRV) System for Reducing Emissions from Deforestation and Forest Degradation-Plus (REDD+). We developed an estimation model of diameter at breast height (DBH) from IKONOS-2 image that led to above-ground biomass estimation (AGB). The IKONOS image was preprocessed with dark object subtraction and topographic effect correction prior to watershed segmentation for tree crown delineation. Compared to the field observation, the overall segmentation accuracy was 64%. Crown detection percent had a strong negative correlation to tree density. In addition, satellite-based crown area had the highest correlation with the field measured DBH. We then developed the DBH allometric model that explained 74% of the data variance. In average, the estimated DBH was very similar to the measured DBH as well as for AGB. Overall, this method can potentially be applied to estimate AGB over a relatively large and remote tropical forest in Northern Borneo.

• Journal of Forest and Environmental Science
• /
• v.33 no.2
• /
• pp.79-90
• /
• 2017

Improving the urban environmental quality relies mainly on the increasing of urban forests capacity to store carbon dioxide. This study assesses the floristic diversity of urban institutional lands in Bukavu and their potential to reduce atmospheric $CO_2$. An exhaustive inventory over three sites ($Coll{\grave{e}}ge$ Alfajiri, $Cath{\acute{e}}drale$ Notre-Dame de la Paix and Institut $Sup{\acute{e}}rieur$ $P{\acute{e}}dagogique$) of Bukavu led to the identification of 1,113 trees of which the diameter at breast height (1.30 m) ranged from 4.9 to 161 cm. Results reveal a floristic diversity made up of 4 families of conifers with 4 species and 14 of broadleaves with 21 species. Average densities were of $54trees\;ha^{-1}$ and $5.21m^2\;ha^{-1}$ of basal area. Urban-based allometric equations used yielded up to 312.8 tons of carbon stored in trees aboveground biomass equivalent to 1,147.9 tons of $CO_2$ reduced from the atmosphere over the three sites. The rate of carbon storage reaches $15.1tons\;ha^{-1}$. Thus, trees of the three institutional sites in Bukavu play an important role in reducing atmospheric $CO_2$ and contribute, thereby, to mitigate global climate change effects. Given the current environmental challenge associated with high population growth rate in cities, the urban forest ecosystem in DRC requires to be extended and further investigation.

• Journal of Ecology and Environment
• /
• v.31 no.4
• /
• pp.333-339
• /
• 2008

We investigated death rates, growth rates and recruitment of culms in two neighboring bamboo (Phyllostachys bamboosoides) stands nested in by two different bird species to analyze stand structure and to design conservation strategies. A third bamboo grove not used by birds, the Taewha stand, was included as a control stand. The bamboo stand occupied by birds in the family Ardeidae (the Ardeidae stand) had an approximately 1.5 times higher culm density than the stand occupied by birds in the family Corvidae (the Corvidae stand). The crude death rate and the number of newly emerged shoots were also higher in the Ardeidae stand than the Corvidae stand. The death rate for bamboo in the Ardeidae stand was not dependent on diameter at breast height (DBH) and was almost 40% for culms of all sizes, whereas most dead culms in the Corvidae stand were < 4 cm DBH. Consequently, we conclude that in the Ardeidae stand, density-independent causes of death are operating, while density-dependent factor are more important in the Corvidae site. The results of soil analysis in these stands suggest that the density-independent death pattern observed in the Ardeidae stand may be due to soil acidification resulting from wastes produced by the birds during breeding. On the other hand, the culm distribution and death patterns in the Corvidae stand suggest that the stand characteristics were not affected by the nesting birds. These results suggest that different conservation strategies must be applied to conserve bamboo groves used by ardeids and corvids for nesting.

• Journal of Forest and Environmental Science
• /
• v.34 no.4
• /
• pp.304-312
• /
• 2018

This study investigates to identify the impact factors of timber production cost on the relationship between production cost components and revenues generated by evaluating the entire timber supply chain. In this research, selected 13 logging zones as target areas and classified 14 forest production cost factors, six groups. Additionally, established 13 externalenvironmental factors with related stakeholders and forestry experts. And the BCR (Benefit Cost Ratio) method was then used to analyze the economics of each zone. Filled up a checklist and rated using 5 point scale for each target region, and extracted major cost factors for the production economy of the item. The analysis of major cost factors in the timber production revealed that wood grab equipment usage fee was the first ranked and forest trees purchase cost was ranked in the $2^{nd}$Also, the $3^{rd}$ranking was logging expenses, and transport cost, which accounted for 84% of the total cost, was ranked in the $4^{th}$. In addition, the rock land ratio, slope, timber payment (forest trees purchase cost), special timber, ratio of timber, DBH (Diameter at Breast Height), and mixed forest ratio were the factors that most affected the timber supply chain cost.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.6
• /
• pp.714-720
• /
• 2015

Since physical and mechanical properties of wood are affected by environmental factors such as soil and climate change, this study investigated relationships between wood quality factors and stand characteristics of Castanopsis cuspidata var. sieboldii forest in the southern region of Korea, including Jeollanam-do Province and Je-ju island. The obtained results found very close relationships between physical and mechanical properties of wood and stand characteristics. The air-dried density and strength performance of woods showed a negative correlation with the diameter at breast height (DBH) while they were positively related to altitude and drainage of the forest site. And wood properties showed variations depending on the region. These results brought a conclusion that wood of Castanopsis cuspidata var. sieboldii in the southern region could be useful forest resources for timber production.

• Journal of Korean Society of Forest Science
• /
• v.40 no.1
• /
• pp.57-62
• /
• 1978

This study was carried out to determine the proper transplanting time of Platanus occidentalis L. (plane tree, sycamore) with 5 to 6 cm and 25 to 30 cm in diameter of breast height at the forest nursery of Chonnam National University in 1977. For that purpose, the experiment of the time of transplantation, and the moisture content and soluble sugar were analysed. The results are as follows: 1. Both its rooting and growth were slightly different in the period of January to early April (before bud-break), but remarkably declined after its bud-break (mid-April to May). 2. And also, its moisture content and soluble sugar were slightly different (January to early April), but, on the other hand, considerably increased in the content of moisture and sharply decreased in soluble sugar after bud-break (mid-April to May). 3. In comparision with healthy trees, rooting and growth of trees infected with Cankers were unusually retarded and its moisture content and soluble sugar were much less. 4. The proper time to plant sycamore was recognized to be the period of November to March, since the higher amounts of soluble sugar and the lesser amounts of moisture in that period. 5. The sudden exposure to the sun of the boles of diseased and wounded trees could be in death in case of sun-scald on the side of south-west. 6. Pruning wounds should be treated with an antiseptic, as soon as they are made, to prevent entrance of decay or disease while the wound is healing. 7. The wound and sun-scald can be presented by covering the trunk with straw ropes before transplantations.

• Journal of Life Science
• /
• v.19 no.6
• /
• pp.693-697
• /
• 2009

The purpose of the present investigation was to investigate diversity patterns in Mt. Neungdong forested landscape. It was conducted on twelve sloping plots $(100{\times}100 m)$ in the east and west sides of Mt. Neungdong. A total of 2,157 specimins were identified as trees with a diameter at breast height (DBH) ${\geq}$10 em. There were a total of 135 species of 35 families present in both regions of Mt. Neungdong. Least significant differences (LSD) by post hoc analysis revealed that region A had significantly greater densities than region B. Shannon-Wiener functions differed significantly between forests (F=4.12, < 0.05), with region B forest having a significantly higher value (2.118) than region A (1.882). Pinus thunbergii and Quercus aliena were dominant on most plots of both regions, however, the P. densiflora forest of region A was distributed better in the middle plots exposures compared to the opposite ones. Q. aliena, Q. mongolica, and Carpinus laxiflora largely occupied the middle and lower exposures of region B. The spatial distribution in Neungdong's forest was very heterogeneous and reflected by most species as having micro-climate and patchy distributions.

• The Korean Journal of Ecology
• /
• v.22 no.1
• /
• pp.21-29
• /
• 1999

This study was carried out to clarify the syntaxonomy of the pine forest in Youngdong region by the phytosociological methods. As a result of the investigation of 62 quadrats, Pinus densiflora forest was classified into four subassociations: Typical subassociation, Quercus mongolica subassociation, Rhododendron mucronulatum subassociation, Rhus chinensis subassociation. Many differences in ecological characteristics such as species composition, stratum structure, vegetation coverage and of diameter at breast height(DBH) of class distribution were found among the communities. Soil properties of the pine forest on the study area was relatively poor compared with other pine forests, especially, soil pH was strongly acidic with 4.87. Soil conditions among the subassociations appeared different. Future succession of pine forest by the similarity index of communities was proposed. Estimated degree of green naturality for Typical subassociation and Q. mongolica subassociation correspond to 7th grade, and R. mucronulatum subassociation, 8-1st grade, and R. chinensis subassociation, 8-2nd grade.

• Journal of Environmental Science International
• /
• v.29 no.5
• /
• pp.519-529
• /
• 2020

The purpose of this study was to provide basic health care data for the climate aspects of park re-cultivation by evaluating air ions according to the type of vegetation in the valley and upper slopes of the mountain park. Simple negative or positive air ions were expected to show the same tendencies, so they were analyzed in terms of correcting the air ion index. By analyzing the air ions according to the topography, it was found that valley > slope in terms of the air ion index. When analyzing air ions according to tree species, we found that evergreen conifers in the valley > the deciduous broad-leaved trees in the valley > the evergreen conifers in the slope = the deciduous broad-leaved trees in the slope. For DBH(Diameter at breast height), the valley large pole > slope large pole > slope medium hard wood, while crown density was analyzed as valley dense > slope dense> valley proper > slope proper. Layered structure analysis showed that the multi-layer structure of the valley > multi-layer structure of the slope = the single-layer structure of the valley > the single-layer structure of the slope. The correlation coefficient was determined according to vegetation type and air ion index in the order of DBH > crown density > layer structure > geomorphic structure. In this study, limits exist except for ridge line, valley, and slopes in urban mountain parks. Therefore, analysis should be made considering both topographical structure and various vegetation types in future studies of air ions.

• Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.163-169
• /
• 2021

Background: Understanding the habitat characteristics of the endangered Siberian flying squirrel Pteromys volans is the first step in conserving and managing the forests it requires for nesting, gliding, and feeding. Therefore, in the present study, we characterized the habitats of P. volans using GIS analysis of 411 forest sites in South Korea where fecal droppings were found. Results: Fecal signs of P. volans were found in various regions in South Korea, including the Baekdudaegan Mountains. GIS analysis with six environmental layers (vegetation type, wood-age class, diameter at breast height [DBH], crown density, elevation, and distance from stream) revealed that fecal signs of P. volans were more frequently found in broad-leaved deciduous forests (42%) located 200-399 m above sea level (43.1%) and 0-199 m from the nearest stream (53%), with 5th class wood-age (35.3%), middle size class DBH (51.1%), and high crown density (71%). Conclusions: The present study provides information on the biotic and abiotic characteristics of P. volans habitats. In South Korea, the fecal droppings of P. volans were found predominantly old deciduous broadleaf forests. Further studies are needed to reveal whether the more frequent occurrence of P. volans dropping in broadleaf forests may be due to a particular preference of this species for the forests or to a simple reflection of the area of the broadleaf forests occupying a much larger area than other forest types in Korea.