• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.209-214
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• 2012

Indigo crop, Persicaria tinctoria H. Gross is an annual plant containing natural colorant, the blue dye indigo, and local cultivars had been cultivated to produce natural indigo for textile dyeing in Korea since ancient times. Naju No. 2 is a new mass-selected line from the mother population, Naju Local cultivar. In this study, two breeding lines of Naju Local and Naju No. 2, have been cultivated in four different locations, the South regions of Korea, to compare plant growth and yield characteristics between two lines. Naju No. 2 was higher in plant height, and Naju Local has more 1st branches. Naju No. 2 has larger leaf area and higher width/length ratio of leaf, showing the round leaf type as morphological stable character without regional differences. Though there was considerable regional variation in fresh and dry top weight of harvested plant, the significant difference of plant weight between two lines were not shown. The ratio of leaf to total shoot of dry weight of Naju No. 2 was higher than one of Naju Local, indicating that Naju No. 2 has better yielding of colorant which is synthesized mostly in leaf. Naju No. 2 contained more Niram (crude indigo extract) and indigo, and showed much blueness at dyeing of silk using fresh leaves than Naju Local. We concluded that a new line, Naju No. 2 could be a superior cultivar due to having higher leaf yield and better quality of natural colorant than Naju local cultivar.

• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.324-336
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• 2004

This study was achieved to present ecological administration plan by analyzing vegetation structure and condition rating class(environmental damage degree) of Sangnim Woods Natural Monument in Hamyang-gun, Korea. In vegetation structure part, actual vegetation was classified by 22 patterns and Quercus serrata Carpinus tschonoskii community(31.8％), Quercus serrata community(14.6％) ranged extensively. Main plant community was 8 types, and is fractionated by 13 plant communities according to stratigraphy development degree it is Quercus serrata community, Quercus serrata Carpinus tschonoskii community, Quercus aliena community, Quercus acutissima community, Carpinus tschonoskii community, Carpinus tschonoskii Quercus serrata community, Zelkova serrata-Quercus serrata community, and Planted area with korean landscape woody plants. Age of old growth trees that diameter of breast height over 38cm was 61∼77years. In condition rating class, area of class 3 was 51,960$m^2$(32.8％), area of class 4 was 6,583$m^2$(3.5％), and area of class 5 was 4,086$m^2$(2.6％) and gross area of class 3∼6 need artificial restoration was 61,619$m^2$(38.9％). Considering actual vegetation, plant community structure, and condition rating class biotope was classified by total 14 types. While distribution area of Queens spp. old growth forest of shrub damaged(51,246$m^2$, 32.4％) and deciduous broad leaved old growth forest of simple-layer structure(19,906$m^2$, 12.6％) is large and that of deciduous broad-leaved old growth forest of multi-layer structure(2,085$m^2$, 1.3％) and Queens spp. old growth forest of multi-layer structure may have to manage with user control by administration plan for stabilization of Sangnim Woods ecosystem for long-term. Also, both vegetation of shrub damaged and simple-layer structure as negative restoration area should be restored for ecological succession and both grassland and planted area with korean woody plants as positive restoration area should be revegetated by using ecological planting model of native vegetation structure in Sangnim Woods.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.443-452
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• 2006

This study was conducted to investigate the site and growth characteristics of Mackia amurensis stand in natural forest of Mt. Joongwang, Pyongchang-Gun, Gangwon-Do, Korea. The 28 sample plots ($30m{\times}30m$) were established to examine the vegetation and site characteristics for M. amurensis stand. Stem analysis was performed on two sample trees for each of the 5 plots situated at intervals of 100 m by altitude. M. amurensis trees were mainly distributed at the ridge and the slope facing north, with altitudes ranging from 790 to 1,170 m. The M. amurensis grew at relatively deep A-layer of soil with high moisture but infertile. Dominant species with M. amurensis were Quercus mongolica, Fraxinus rhynchophylla, Acer pseudo-sieboldianum, A. pictum subsp. mono, Ulmus davidiana var., japonica, Tilia amurensis, and Populus davidiana. TWINSPAN classified four communities in Mt. Joongwang area; M. amurensis-P. davidiana community (xeric type), M. amurensis-U. davidiana var. japonica community (xeric type), M. amurensis-T. amurensis community (moist type), and M. amurensis-Styrax obassia community (moist type). According to the community type, trees per ha were more abundant in the area of the moist types than the xeric types. Height growth of M. amurensis increased with increasing ages until 10 years, and then decreased thereafter, especially at altitude of 1,020m. M. amurensis showed rapid early growth of height and volume, indicating possible high biomass production under enough light. Growth of M. amurensis increased greatly at about 40 years if released from severe competitions. The rotation age of natural M. amurensis stand was expected for above 50 years.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.380-385
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• 2002

The sand shrimp, Crangon hakodatei commonly occured in the southern coast of Korea. The population structure, growth, mortality, and size at sexual maturity of C. hakodatei were examined by the samples collected from the coastal area of Geoje Island, Korea from October 2000 to October 2001. For estimation of parameters of growth and mortality, monthly length-frequency data were analysed by ELEFAN. Parameters of growth were estimated, using the modified yon Bertalanffy growth function model. The female grew faster and reached larger size at the same age than the male, There was a breeding season showing a peak in winter (January to february). Total mortality by length-converted catch curve was estimated at $3.10 yr^{-1}$, fishing mortality was $0.62 y^{-1}$ and natural mortality was $2.48 yr^{-1}$. The size at $50\%$ sexual maturity for the female ranged from CL 11.00 to 11.50 mm.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.305-320
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• 1996

It is necessary to obtain information about the productivity of the human-influenced forest and to understand the consumption of biomass resources in secondary forest in order to examine the resource flux by human activity in rural landscape. Thus the aims of this study were to elucidate the biomass and their use of secondary Pinus densiflora forests and to discuss sustainable utilization of secondary forests in rural landscape system. This study was carried out in Yanghwa-ri, Kongjugun, Chungcheongnam-do, central Korea. The changes of growth rate and aboveground biomass of a pine forest for 2 years were analyzed to understand forest management regimes in rural pine forests. Through allometric equations deduced from 25 sample trees, biomass was estimated. The biomass increase of pine forest was approximately 16.36 t/ha/yr in the unexploited stand and 12.24 t/ha/yr in the exploited stand. These were nearly equal to those of natural pine forests in central Korea. This result proved that human-influenced pine forest in rural landscape as well as the natural one has high potentiality to provide forest products. Making graveyard in forest-land was the important disturbance and land-use which currently occurring in rural landscape in the study area. Finally, we presented some forest management for stutainable and positive uses of secondary forests as one of the local energy resources in terms of the holistic landscape-ecological view.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.2
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• pp.129-140
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• 2008

This study was performed to estimate biomass and to provide management plan through population ecological characteristics, including growth parameters, survival rate, instantaneous coefficient of natural and fishing mortalities, and age at first capture of hen clam, Mactra chinensis, in the Dong-li self-regulatory community of Busan. The von Bertalanffy growth parameters estimated from a non-linear regression were $SH_{\infty}=86.24mm$, K=0.12/year, and = -1.37year. Survival rate(s) of the hen clam was 0.515. The instantaneous coefficients of natural mortality(M) was estimated to be 0.232/year and fishing mortality(F) 0.432/year for hen clam. The current biomass of the hen clam in the study area was estimated to be 713mt and the acceptable biological catch(ABC) was estimated under various harvest strategies based on $F_{0.1}$ and $F_{40%}$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.222-228
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• 2012

This study was conducted to determine the natural succession process after forest fire by comparing height, relative growth rates in height (RGH), and tree density of pine seedlings with different fire severity. In the area damaged by surface fire, tree density was highest during the first 5 years after fire. However, in the area damaged by crown fire, tree density rapidly increased during first 5 years after fire. Pine seedlings were found only on the place with ridges, barren soil, and the aspect of north. Annual height growth of pine seedlings was decreased with time in all study sites. The empty space in pine stands gradually decreased by the invasion of Quercus species. The forest fire altered the pine forest into oak forest rapidly. In contrast, pine seedlings invaded steadily on the oak forest in the rocky area or the area with ridges.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.331-339
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• 2023

This study was conducted to identify seed inflow characteristics according to harvest typeand to provide basic data for developing a regeneration technology for secondary growth forests in Korean red pine (Pinus densiflora) succession forest formation by natural regeneration. Experimental sites were established by applying seed tree (single and group) and clear-cutting methods (10- 20- 30-m strip and 20- 30- 40-m patch). The seed inflow characteristics of the natural regeneration site were analyzed for 6 years from 2014. Most seeds were flowed to the regeneration stand from October to November. In years with good seed fructification, more than 80% were flowed in October. The average annual seed inflow by harvest type was highest in the seed tree area (296,000 seeds/ha/yr), followed by the 20-m patch clear-cutting area (291,000 seeds/ha/yr) and 10-m strip clear-cutting area (281,000 seeds/ha/yr). The distribution uniformity of seed inflow according to treatment was analyzed in the order of the 20-m strip clear-cutting area (52.2), 20-m patch clear-cutting area (52.9), and 10-m strip clear-cutting area (56.1). As a result, the 10-m strip and 20-m patch clear-cutting areas with relatively small harvest areas showed high seed inflow and distribution uniformity.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.4
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• pp.1-8
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• 1999

Forest devastation in Korea was caused by several factors such as internal factors from geological features and external factors from artificial forest damages including fuel wood collection from forests, forest fires, shifting cultivations and so on. According to the reports of 1935, lots of forest devastation in Kyungpook province area occurred around the main and branch stream of Nakdong river. Main factors of occurring forest devastation in 1935 were investigated by the methods of forest devastation rate and the population density at the basin of Nakdong river. But based on our study, forest devastation mainly occurred in rock zones of granite and granite gneiss, next to Nakdong formation but scarcely occurred in Hayang formation. Clay of the weathered soils of granite and granite gneiss was lost by rainfall, but remaining coarse-sandy soils(or grits) have poored conditions in vegetation's growth, which are due to high level of water permeability, lack of water-holding capacity and dried conditions. Generally, pine forests are mainly growing up in these regions. It is supposed that forest devastation was accelerated due to long periods of natural regeneration and no ability of natural regeneration by sprout after frequent collections of fuel wood and cuttings from pine forest on those grit areas. These results indicated that the high rate of forest devastation occurred around the basin with the high resident population density, which was partly due to forest damages by fuel collection. Moreover, both geological features and number of residents had much influence on forest devastation. Forest devastation was positively correlated with those variables(r=+0.73).

• Journal of Forest and Environmental Science
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• v.36 no.3
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• pp.233-242
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• 2020

The Lake (Victoria) zone of Tanzania, which has the least forest resources in the country, is a potential economic growth zone in the country. Therefore, this study analyses the impact of implemented forest policies on the status of forest resources in the area, given the unique features. The study identifies the status of forested lands in the area, and then fits binary logistic regression to identify the impact of policies related elements (i.e. type of forest, type of management) on the status; forest area and location (region) are used as control variables. Results show that 63% of the forested land in the area is destructed; main activities being agriculture, residential, firewood, and charcoal burning activities. Logistic results showed natural forests, forests located in Geita region, forests managed by municipal councils are more likely to be destructed; while plantation forests, forests located in Kagera region, privately managed forests are less likely to be destructed. Thus, the study concludes that policies and measures are not enough for the preservation of forest resources in the area; some of the economic activities in the area are occurring at the expenses of the forests; hence recommend more sustainable development plans and incorporating different crossing cutting sectors in the policies.