• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.93-102
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• 2019

The materials of artificial soils in the production process of container seedlings have a great influence on plant growth. Peat moss, vermiculite, and perlite have been used as major components of artificial soils for many years; however, they could decrease carbon fixation carried out by the soil and cause environmental problems such as a change in the water quality. Thus, environmental friendly materials to replace them must be developed. The purpose of this study was to verify the optimum additive materials of artificial soils and their mixed ratios for the growth and seedling quality index (SQI) of Quercus serrata. Rice husk, mushroom sawdust, and pine bark were each used as an additive material and mixed into the growth medium at 10% and 20% of the total volume. There was no significant difference in the height growth of Q. serrata. The 20% mushroom sawdust decreased the root collar diameter by 23.4% compared to the control. The total dry weight was highest with the 10% rice husk and was significantly lower by 10.3% for the 20% mushroom sawdust compared to the control. Additionally, the SQI for all the treatments showed no tendency to increase compared with the control. Thus, this study showed the possibility of recycling biomaterials from agriculture and forest for seedling production. This method could reduce environmental problems and help eco-friendly nurseries to achieve a carbon negative impact by the recycling of by-products.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.111-116
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• 2015

The purpose of this study was to evaluate mixed model of dbh-height relation containing random effect. Data were obtained from a survey site for Quercus variabilis in Gangwon region and remeasured the same site after three years. The mixed model were used to fixed effect in the dbh-height relation for Quercus variabilis, with random effect representing correlation of survey period were obtained. To verify the evaluation of the model for random effect, the akaike information criterion (abbreviated as, AIC) was used to calculate the variance-covariance matrix, and residual of repeated data. The estimated variance-covariance matrix, and residual were -0.0291, 0.1007, respectively. The model with random effect (AIC = -215.5) has low AIC value, comparison with model with fixed effect (AIC = -154.4). It is for this reason that random effect associated with categorical data is used in the data fitting process, the model can be calibrated to fit repeated site by obtaining measurements. Therefore, the results of this study could be useful method for developing model using repeated measurement.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.772-779
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• 2009

This study was conducted to estimate the carbon (C) contents in pure and mixed stands of pine (Pinus densiflora) and oak (Quercus spp.) trees for establishing the C inventory of forest ecosystems. A total of fifteen 20 m${\times}$20 m pure and mixed stands of pine and oak trees were chosen in natural forests in Hoengseong, Kangwon based on the basal area of all trees ${\geq}$ 5 cm DBH: three of 95% of pine and 5% oak trees [pine stand], three of 100% of oak trees [oak stand], and nine of 20 to 70% of pine and 80 to 30% of oak trees [mixed stand]. To estimate C contents in the study stands, biomass in vegetation, forest floor and coarse woody debris (CWD) were calculated and C concentrations in vegetation, forest floor, CWD and soil (0-30 cm) were analyzed. There was no significant difference in vegetation C contents among the stands; 147.6 Mg C/ha for the oak stand, 141.4 Mg C/ha for the pine stand and 115.8 Mg C/ha for the mixed stand. Forest floor C contents were significantly different among the stands (p<0.05); 12.7 Mg/ha for the pine stand, 9.9 Mg/ha for the oak stand, and 8.4 Mg/ha for the mixed stand. However, CWD C contents were not significantly different among the stands (p>0.05); 2.2 Mg/ha for the mixed stand, 1.7 Mg/ha for the oak stand, and 1.1 Mg/ha for the pine stand. Soil C contents up to 30 cm depth were not significantly different among the study stands; 44.4 Mg C/ha for the pine stand, 41.6 Mg C/ha for the mixed stand, and 33.3 Mg C/ha for the oak stand. Total ecosystem C contents were lower in the mixed stand than those in the pure stands, because vegetation C contents which occupied almost total ecosystem C contents were lower in the mixed stand than those in the pure stands; 199.6 Mg C/ha for the pine stand, 192.5 Mg C/ha for the oak stand and 169.1 Mg C/ha for the mixed stand. Lower vegetation C contents in the mixed stand might be influenced by interspecific competition between pine and oak trees and intraspecific competition among the oak trees resulted from high stand density. We suggest that forest management such as thinning to enhance C storage is indispensible for minimizing the competition in forest ecosystems.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.368-374
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• 2015

On the basis of vegetation data by point quarter sampling method, the natural forest of Jirisan(Mt.) was classified into eight forest types by cluster analysis. They were Quercus mogolica forest type, Fraxinus mandshurica - Betula costata forest type, Mixed mesophytic forest type, Abies koreana forest type, Carpinus laxiflora forest type, Quercus serrata forest type, Pinus densiflora forest type, and Quercus variabilis forest type. Then, succession index was estimated for each forest type so as to evaluate succession process comparatively among forest types. The results showed that Carpinus laxiflora forest type had highest succession index of 219.7, followed by Mixed mesophytic forest type with little difference of the index of 218.3. Pinus densiflora forest type had lowest index. Succession indices were hardly correlated with species diversity indices of forest types. We presumed that the higher value of succession index a forest type had, the closer toward the climax forest. However, the estimated index was not supposed to be absolute level of successional stage, but it could play a role of comparative assessment in the position of the seral stage among forest types.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.197-202
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• 2009

We studied bird communities among in rice field (46 plots), short grallland (47plot), and tall grass mixed shrub (21 plots) during dry season, January 2007 in Boeung Prek Lapouv (BPL) Important Bird Area, Mekong Delta, Cambodia using the point-count method. Water depth, vegetation height and shrub density were significantly different among the three study areas. We recorded, 60 bird species, of which 13 differed significantly among habitats. Landbirds such as Grey-breasted Prinia (Prinia hodgsonii) and Oliver-black Sunbird (Nectarinia jugularis) were much more abundant (P<0.0001) in the tall grass mixed shrub, whereas the Sarus Crane (Grus antigone), herons and egrets were more abundant in the short grass (P<0.05). Bird species richness and species abundances were not significantly different among habitats. Bird species diversity (H') was higher in grasslands than in rice fields. Mosaic habitat matrix, such as rice field, short grass, and tall grass mixed shrub, should be maintained for the extend and quality of wetlands, and the prevailing human-land use patterns, appear adequate and conductive for waterbirds in the Mekong Delta, Cambodia.

• Journal of Forest and Environmental Science
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• v.35 no.1
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• pp.25-30
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• 2019

The composition of artificial soil in a containerized seedling production plays an important role in seedling quality as well as environmental issues. We investigated the effects of different types of biomaterials and mixed ratio with artificial soil on the growth of Fraxinus rhynchophylla seedlings. Soil medium was supplemented with 3 levels (0%, 10%, 20%) of pine bark, mushroom sawdust and rice husk. Root collar diameter (RCD), height growth, and biomass have significantly increased when rice husk was applied. Compared with the control, RCD and height growth showed highest in 20% rice husk treatment with an increase of 5.7% and 17.6%, respectively. In contrast, the treatments of pine bark and mushroom sawdust showed lower results in growth parameters (RCD, height growth, and total biomass) than control. Seedling quality index was also highest at the 20% rice husk treatment, but there was not statistically different among treatments. Our results suggested rice husk can be substituted up to 20% of substrates for containerized F. rhynchophylla seedling production system.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.10a
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• pp.9-18
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• 2011

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.467-469
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• 2003

This research aimed to develop forest type classification technique for the mixed forest with coniferous and broad-leaved species using the high resolution satellite data. QuickBird data was used as satellite data. The method of this research was to extract satellite data for every single tree crown using image segmentation technique, then to evaluate the accuracy of classification by changing grouping criteria such as tree species, families, coniferous or broad-leaved species, and timber prices. As a result, the classification of tree species and families level was inaccurate, on the other hand, coniferous or broad-leaved species and timber price level was high accurate.

• Journal of Korean Society of Forest Science
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• v.97 no.2
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• pp.165-170
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• 2008

Litterfall has been recognized an important part of the forest ecosystem production, playing a major pathway in energy flow and nutrient cycling through the ecosystem. This study was carried out to examine the quantity and components, temporal variation, and spatial heterogeneity of the litterfall in the mixed broadleaved-Korean pine forest. The data were collected from the 9ha permanent experimental plot, of which on the center area, i.e. $150m{\times}150m$, the total number of 319 circular litterfall traps with the size of $0.5m^2$ were established to collect falling litterfall. The results showed that the annual amount of litterfall was totalized 3,033.7 kg/ha, occupying broad-leaves of 39.3%, conifer-leaves of 29.5%, others of 18.5%, branches of 10.4%, and seeds of 2.3%. The peak point of the litterfall production was made at the end of September, proportionating 32.2% of total amount. The analysis of semivariogram revealed the existence of high spatial heterogeneity, calculated the scale of spatial heterogeneity ranged from 11.6 m to 29.1 m. The result of proportion (C/[Co+C]) showed that spatial heterogeneity of autocorrelation in total spatial heterogeneity were from 97.0% to 100%. The relatively heavy branches and others had significant differences in litterfall production between the areas of canopy gap and closed canopy in the 95% probability level, but the other components did not show statistical differences.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.781-790
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• 2019

Changes in the physical and chemical properties of soil materials during the nursing process have a great influence on the quality of containerized seedlings and on growth and survival after planting. In this study, the effect of biomaterials and their mixed ratios on the growth of Zelkova serrata seedlings in a containerized seedling production system was investigated. Mushroom sawdust, pine bark, and carbonized rice husk were used as biomaterials. The mixed ratios were 10% and 20% volume ratio of the growing medium volume, including the untreated controls. There was no significant difference in the height growth of the Zelkova serrata seedlings according to the biomaterials. The root collar diameter was the highest with the 20% carbonized rice husk and the lowest with the mushroom sawdust. The difference between the highest quality index and the lowest quality index was 30% in the order of the carbonized rice husk, pine bark, control, and mushroom sawdust, but there was no statistical significance. In this study, if the growing medium mixed with biomaterials does not reduce the seedling growth compared with the control, it is considered that the biomaterial can replace a part of the growing media. Therefore, the results show that some of the growing media can be replaced with carbonized rice husk or pine bark when producing Zelkova serrata seedlings.