• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.710-716
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• 2011

The growth characteristics and the several component content of leaves in one year old tetraploid of Robinia pseudoacacia introduced at five site planted respectively were surveyed in Sangwon area Pyongyang, and the expand plant possibility and the leaves harvested as feed additive use of possibility in Democratic People's Republic of Korea was discussed in comparison with tetraploid of R. pseudoacacia of Yanqing area. The results were as follows (1) the length and stump diameter of annual sprouting stems at Sangwon area were smaller 50% than the tetraploiod of R. pseudoacacia stems that Yanqing area; (2) the length of sprouting stems in slope sites of Eastern (E), Western(W) and Southern(S) at Sangwon were higher 23~30% than the length that Northern slope site(N), and the diameters of sprouting stem in the slope of Eastern(E) and Southern(S) were higher 14~23% than the slope sites of Northern(N) and Western(W); (3) crude protein contents and ash contents of leaves at Sangwon were higher 40% general R. pseudoacacia and similar to the leaves that Yanqing area.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.163-168
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• 1986

This study was carried out to compare the conditions of Korean and Japanese forestry. Two countries were appeared same trend in forestry condition, so our forestry in future can be estimated with compared Japanese forestry, but the results obtained are as follows ; 1) The average forest area per capita of the world, Japan and Korea are 0.9, 0.23 and 0.16 ha, respectively, this means that Korean forest area is not sufficient. The growing stock of forest per capita is $22.5m^3$ in Japan and $3.9m^3$ in Korea, but timber consumptions per capita are $1m^3$ in Japan and $0.2m^3$ in Korea. Those mean that both countries have not a plentiful resource of forestry. 2) The forestry production activity becomes gradually stagnation. Both in Korea and Japan, the reforestation and stumpage felling area show gradually decreasing tendency, the artificial forest ratio of total forest area is, at present, 28% in Korea and 40% in Japan. 3) In forestry demand aspect, the ratio of imported timber is 79% in Korea and 62.4% in Japan. Because the price index of timber is lower than the general price index, the dullness of forestry-related industries is expected in future. 4) The forestry labour supply has gradually difficulty because of the reduction in farming labour. 5) The managements of national forests show deficit operation, at present, both in Korea and Japan. The results above mentioned are derived form the poor forest resources, therefore, it is considered that rather more and continuous investment is necessary, but also forestry should be invested in the territorial conservation aspect.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.413-418
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• 1990

Since 1945, the periodical reforestation projects considered as the fundamental apparatus of the forest policy of the Government have been continuously carried out during last 40 years in Korea. As a result, some of the forests are ready to be harvested, especially in well-managed plantations as well as in the natural forests. This requires to pay more attention to harvesting the timber rather than planting trees. At the present, such timber harvesting operations such as cutting, felling, bucking, and skidding and yarding, particularly yarding operations in mountain areas with harsh terrains are in the most cases depend upon man power. However, the yarding operations should be more mechanized in the near future in Korea mainly because of the high cost of labour couppled with the lack of labour in forested areas. The Forest Work Training Center attached to the Forest Administration imported and tested the smallsized cable crane(K-300) with movable tower. The result of economic analysis of the yarding operation expenditures shows that the cable crane yarding costs more than the man yarding at the present time. As the labour cost will gradually increase and the efficiency of machine operation will improve, the results of the study indicates that the yarding operation by cable crane will be more cost-effective in the future.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.355-368
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• 2021

This study aims to identify appropriate tree species and crops for agroforestry target sites in North Korea based on ecological geography and site properties. To this end, an ecological geographic map (13 regions and 4 zones) of North Korea was made using satellite images and North Korean academic journal articles. The target agroforestry sites were selected and mapped according to 18 site conditions depending on 3 site characteristics, and the sites were divided into short-term and long-term target sites depending on the agroforestry management period. Finally, optimal combinations of 30 tree species and 19 crops were selected by overlapping the ecological geographic map and agroforestry target site map. For regions within the same zone, tree species and crops were almost similar; however, compared to regions in other zones, they differed. This is likely because the geographical climatic characteristics reflected in the ecological geographic map vary greatly from zone to zone. These results will be used to propose a combination of suitable tree species and crops that takes into account both management purposes and management types for inter-Korean forest cooperation in the agroforestry sector.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.81-85
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• 2019

This study was carried out to observe the changes of seaweed community in artificial reefs installed in September, 2016 in Namae-ri, Yangyang-gun, and Seokbyeong-ri, Pohangsi, Korea. Field surveys were conducted by SCUBA diving once a season in February, May, August, and November of 2017, and quantitative survey and qualitative survey were carried out in parallel. In this study, a total of 94 species, including 11 green algae, 15 brown algae and 68 red algae were appeared. 66 species (8 green algae, 9 brown algae, 49 red algae) and 65 species (7 green algae, 9 brown algae, 49 red algae) were collected and identified in Yangyang and Pohang. In dominant species, Yangyang was dominant species of Saccharina japonica and subdominant species of Ulva australis. Pohang dominated in order of Colpomenia sinuosa and Gelidium elegans. In both coastal areas, Ulva spp., Colpomenia sinuosa were grown at the early stage of reforestation, and perennial seaweeds such as Saccharina japonica, Ecklonia cava and Gelidium elegans were grown. In order to clarify the clustering relation through flora change, it is necessary to monitor the transition process until the seaweed community is stabilized by observing the long-term change through continuous monitoring.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.400-412
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• 2020

We analyzed the growth characteristics of naturally regenerated seedings of Larix kaempferi in order to propose a field-applicable regeneration method. Experimental sites were established at Gapyeong in Gyeonggi-do and at Bonghwa in Gyeongsangbuk-do. We analyzed seed inflow features, occurrence, and growth characteristics of natural seedlings for three years. The reserved seed-tree site producedthe greatest number of inflow seeds and followed by seed-tree site and clear-cut site. In addition, the reserved seed-tree method was found to be more efficient than other methods in evenly scattering seeds. The rate of seedling occurrence at treatment sites (e.g., harvesting and scratching) was 2.4%, which is 8.0 times higher than the seedling occurrence (0.3%) at the non-treatment sites. There were approximately 470,000 seedlings per hectare at the treatment sites in June of the first year after regeneration and approximately 78,000 seedlings per hectare in October of the third year. The average diameter of the root collar of the seedlings in the third year was 6.5 mm, and the average height of the seedlings was 50.4 cm. These results indicate that it is possible to create a secondary forest of L. kaempferi by natural regeneration if harvesting and scraping are implemented during seed fructification. Considering the rapid growth of L. kaempferi shown in this study, the proposed method would be an efficient reforestation technique.

• Clean Technology
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• v.26 no.4
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• pp.239-250
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• 2020

Biomass is an abundant renewable energy resource that can replace fossil fuels for the reduction of greenhouse gas (GHG). Indonesia has a large number of cheap biomass feedstocks, such as reforestation (waste wood) and palm residues (empty fruit bunch or EFB). In general, raw biomass contains more than 20% moisture and lacks calorific value, energy density, grindability, and combustion efficiency. Those properties are not acceptable fuel attributes as the conditions currently stand. Recently, torrefaction facilities, especially in European countries, have been built to upgrade raw biomass to solid fuel with high quality. In Korea, there is no significant market for torrefied solid fuel (co-firing) made of biomass residues, and only the wood pellet market presently thrives (~ 2 million ton yr-1). However, increasing demand for an upgraded solid fuel exists. In Indonesia, torrefied woody residues as co-firing fuel are economically feasible under the governmental promotion of renewable energy such as in feed-in-tariff (FIT). EFB, one of the chief palm residues, could replace coal in cement kiln when the emission trading system (ETS) and clean development mechanism (CDM) system are implemented. However, technical issues such as slagging (alkali metal) and corrosion (chlorine) should be addressed to utilize torrefied EFB at a pulverized coal boiler.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.330-344
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• 2022

While deforestation and forest degradation has continued globally, global society has been making efforts to prevent deforestation towards sustainable development. Reforestation in developing countries is linked to Sustainable Development Goals (SDGs) such as climate change mitigation, conservation of biodiversity, eradication of poverty and upholding of human rights. Forest official development assistance (ODA) restores the global forest land, and increases the public benefit. Bilateral forest ODA projects of the Republic of Korea have gradually increased and most of those projects have currently been concentrated in Asian countries. Selecting recipient countries for forest ODA requires more comprehensive approach since the global goals for sustainable development has been widely adapted to ODA strategic plans. We proposed potentially promising countries that are eligible for receiving 'Green ODA' in perspective of economic, social and environment to implement reducing emissions from deforestation and degradation (REDD+), conserving biodiversity, and combating desertification. As a result, the study suggests that forestry cooperation could be expanded from Asian countries more toward South America and African countries. In addition, we emphasized the need to promote convergence and integration with green technology to fundamentally solve the negative impacts of deforestation such as food, energy, water resource shortages, and forest fires. We advocated expanding bilateral ODA in the forestry sector through diversification of project activities, financial sources, and participants. Our study can contribute to the provision of basic information for establishing long-term strategies to expand bilateral cooperation in the forestry sector.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.330-338
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• 2023

To investigate the impact of forestry projects on the carbon stocks of forests, we estimated the carbon stock change of above-ground and soil before and after forestry projects using forest type maps, forestry project information, and soil information. First, we selected six map sheet with large areas and declining age class based on forest type map information. Then, we collected data such as forest type maps, growth coefficients, soil organic matter content, and soil bulk density of the estimated areas to calculate forest carbon storage. As a result, forest carbon stocks decreased by about 34.1~70.0% after forestry projects at all sites. In addition, compared to reference studies, domestic forest soils store less carbon than the above-ground, so it is judged that domestic forest soils have great potential to store more carbon and strategies to increase carbon storage are needed. It was estimated that the amount of carbon stored before forestry projects is about 1.5 times more than after forestry projects. The study estimated that it takes about 27 years for forests to recover to their pre-thinning carbon stocks following forestry projects. Since it takes a long time for forests to recover to their original carbon stocks once their carbon stocks are reduced by physical damage, it is necessary to plan to preserve them as much as possible, especially for highly conservative forests, so that they can maintain their carbon storage function.

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.1-23
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• 1973

The results of ground vegetation experiment conducted at completely denuded forestland in the mudstone region are summerized as follows: On the reaults of soiling quantity the effect of soiling was observed where depth of soiling over 10 cm was practiced, and a plot where treated with 15cm soiling and without fertilizer showed poor growth and it was even worser than the plot where soiling was practiced only 1 cm in thikness but applied adequate amount of fertilizers. The depth of slits between 30cm and 40cm showed no significant difference in the effect. A plot where covered with vegetation bag showed somewhat better results in seed loss and early growth but no differences observed in the fall result over the none covered plot. And then, it is recommendable to have soiling over 10cm in thikness with slit of 30cm and 30cm in depth and to apply 30 gram of fertilizer (22;22:11, 50 gram) per slit. On various soiling materials trial there were no striking differences in the effect of soiling between weathered granite soil, wheathered tuffs soil and weathered mudstone soil. In the treatment with various green materials, a plot treated with straw mat showed a significant difference at 1 percent. The results show that weathered mudstone soil is effective to use as soiling materials and straw mat treatment was better. On forest fertilization trial, in the mudstone region where red and black pine trees already existing at a rate of 2,000-3,000 trees per hectare had applied 110kg of compound fertilizers (9:12:3 and 22:22:11) per hectare basis in terms of plant nutrient. As a result, the difference in effect between the compound fertilizers was not found however the leaf color and leaf length of the fertilizer added plot showed darker and longer at 30 percent over the no fertilizer received plot. Compound fertilizers, 14:37:12 and 9:12:3 were applied to alder trees at a rate of 20 gram and 40 gram per tree in terms of plant nutrient and a remarkable growth accelerantion was observed where 40 grams of plant nutrient applied. The effect difference between the compound fertilizers was not found. On investigation of tree root elongation, forty years old red pine trees showed only 15cm tap root elongation through mudstone while black pine had 23 cm tap root elongation. The total length of supporting root elongtion of red and black pines showed 20 and 13 meters, respectively. The tap roots of Black locusts were not able to elongate through mudstone, however, the supporting roots tended to develop to the underneath of pine tree where some moisture content is available. Black locusts And grown on the residual soil of mudstone normally die between 8 to 10 years. The red pine trees show flat in tree shape while black pine had triangle in the shape. With the results it can be said that in an artificial reforestation in denuded forest land of the mudstone region the adequate slit and enough amount of fertiliizer application must be provided for the succesful performance of the program. On integrated experimental results of 1972. for the establishment of ground vegetation on the completely denuded forest land in mudstone region, soiling could be effectively practiced with weathered mudstone soil and it would not specially necessiate to have either weathered granite or tuffssoil for the soiling. And the soiling depth should be more than 10 cm in thickness. Among green materials used the straw mat proved to be the most effective reatment. Three major factors which enable to establish ground vegetation by the shortest period of time: A. Physical improvement of soil is necessary to breakdown of the horizontal cracks sushas Slit, contour line plot, seeding hole and etc., and soiling with weathered mudstone soil. B. Chemical improvement of soil: is needed sufficient amount of fertilizer application 300~400kg ha, $N+P_2O_5+K_2O$), and increased production of ground covering and expedite resolution of the vegetation (ground vegetation, fallen leaves and twigs). C. Complete establishment of the basic structure for the erosion control (Prevention of surface soil erosion)