• Journal of agriculture & life science
• /
• v.44 no.6
• /
• pp.15-22
• /
• 2010

This study was carried out to investigate the characteristics of ions in rainwater by stem flow, through fall and rainfall in Pinus thunbergii forest in Ulsan industrial complex area and Mt. Jiri area. pH of rainwater in Ulsan industrial complex area was low as compared with those in Mt. Jiri area. EC of rainwater in Ulsan industrial complex area was mainly high and there was twice difference in stemflow and through fall as compared to Mt. Jiri area. The concentration of major ions in rainwater, especially $Ca^{2+}$ and $Mg^{2+}$ in stem flow were generally high at Ulsan industrial complex area, while anions were high in the order of ${SO_4}^{2-}>{NO_3}^{-}>Cl^-$ in both areas. There was a wide difference in ${SO_4}^{2-}$ concentration in the stem flow between both areas. ${SO_4}^{2-}$ from air pollutants will result into acidification of forest soils and thereafter cause damages on forest ecosystems.

• Journal of Korean Society of Forest Science
• /
• v.110 no.4
• /
• pp.658-664
• /
• 2021

This study aimed to develop accurate status site index curves for C. japonica in Gyeongsang-do that reflect the regional characteristics. The development of high-growth models in Chapman-Richards, Schumacher, and Gompertz for 552 C. japonica growing in Gyeongsang-do. The Gompertz growth function is the most suitable for developing site index curves. The comparative test was analyzed using the F test at a significance level of 5% and the graph. As a result, compared with the national site index curves and site index curves under base age in Jeolla-do, the p-value was 0.05 or higher, and there was no statistically significant difference. The p-value was 0.05 or lower compared with site index curves over stand age in Jeolla-do, indicating a statistically significant difference. Therefore, it was determined that site index curves for C. japonica in Gyeongsang-do can be applied to the national site index curves and site index curves under base age in Jeolla-do, but not to site index curves over base age in Jeolla-do. Hence, based on the results of the study, it is possible to provide basic data on the forest management system for C. japonica in Gyeongsang-do and systematic and reasonable management through high field application reflecting regional characteristics.

• Journal of Korean Society of Forest Science
• /
• v.108 no.1
• /
• pp.127-132
• /
• 2019

This study aimed to investigate the differences in habitat environment and characteristics of small rodent populations with time elapse after thinning in Japanese larch (Larix kaempferi) plantations, Mt. Janggun, Gyeongbuk Province, South Korea. We found that there were significant differences in habitat environment, number of tree, shrub stems, coverage of overstory, midstory, rock and number of coarse woody debris (CWD) between thinned and unthinned forest stands. We captured four small rodent species. Total number of captured small rodent were higher in thinned stands. Male-to-female ratio of Apodemus agrarius, and A. peninsulae were both the highest in forest stand 3 year after thinning. The differences in number of captured and sex ratio of small rodents might be related to habitat environment between thinned and unthinned stands. Thus, thinning can provide good habitat for small rodents by developing understory vegetation and increasing CWD in Japanese larch plantations. These results suggest that forest management through maintenance of CWD and induction of midstory and understory vegetation after thinning is necessary to maintain small rodents diversity.

• Korean Journal of Environment and Ecology
• /
• v.38 no.2
• /
• pp.156-168
• /
• 2024

This study was carried out to provide fundamental data for forest land and the environment by investigating the vegetation structure and soil properties of forest land where Sarcodon impricatus are present. The study area was divided into the Quercus mongolica community, dominated by Q. mongolica and the Quercus variabilis community, a mixed forest with Q. variabilis, Q. mongolica and Pinus densiflora. Also, Calamagrostis arundinacea in the former community and Disporum smilacinum and Carex siderosticta in the latter community showed significant levels as indicator species. Both communities showed a strong correlation between available phosphate and pH, sand, and clay, and the high organic matter content and slightly acidic pH of the soil are believed to be related to the development of S. impricatus. The species appearing at the lower layer continue to dominate because the species appearing at the upper layer have secured realized niches. The site was distributed in a relatively humid place in a north-east direction, and soil was developed with a thin litter layer and low rock exposure. In the selected S. impricatus growing areas, vegetation centered on highly adaptable species to disturbance or external interference was developed. Therefore, it is expected to be used as fundamental data to promote the occurrence of S. impricatus during artificial cultivation, as it is possible to identify the stand where S. impricatus occurs indirectly.

• Journal of Korea Water Resources Association
• /
• v.57 no.3
• /
• pp.195-207
• /
• 2024

This study selected major drought events that occurred in the Jeonnam region from 1991 to 2023, examining both meteorological and hydrological drought occurrence mechanisms. The daily drought index was calculated using rainfall and dam storage as input data, and the drought propagation characteristics from meteorological drought to hydrological drought were analyzed. The characteristics of the 2022-23 drought, which recently occurred in the Jeonnam region and caused serious damage, were evaluated. Compared to historical droughts, the duration of the hydrological drought for 2022-2023 lasted 334 days, the second longest after 2017-2018, the drought severity was evaluated as the most severe at -1.76. As a result of a linked analysis of SPI (StandQardized Precipitation Index), and SRSI (Standardized Reservoir Storage Index), it is possible to suggest a proactive utilization for SPI(6) to respond to hydrological drought. Furthermore, by confirming the similarity between SRSI and SPI(12) in long-term drought monitoring, the applicability of SPI(12) to hydrological drought monitoring in ungauged basins was also confirmed. Through this study, it was confirmed that the long-term dryness that occurs during the summer rainy season can transition into a serious level of hydrological drought. Therefore, for preemptive drought response, it is necessary to use real-time monitoring results of various drought indices and understand the propagation phenomenon from meteorological-agricultural-hydrological drought to secure a sufficient drought response period.

• Journal of The Korean Association For Science Education
• /
• v.26 no.6
• /
• pp.703-722
• /
• 2006

The purpose of this study is to investigate the characteristics of abduction suggested by C. S. Peirce, and to discuss its implications in science education. Peirce's abduction is the logic of generating hypothesis. Abduction is a kind of logical inference, which colligates general rule and the observed result, and then it makes us judge the observed result as a case of the general rule on the basis of their resemblance. The process of abduction is also the logic of inquiry. In a Peirce's view, inquiry is a struggle for escaping from the condition of 'doubt' and to 'belief the nature of which is the establishment of habits. Because what habit an object has is its whole meaning, in his views, the fixation of belief is the way of attaining the truth related to it. The beliefs of individuals, however, are always fallible. So, to attain a truth, we need the terminal opinion of community of inquiry that could conduct infinite inquiry. These characteristics of Peirce's abduction give suggestions in science education as follows; firstly, hypothesis generating which transforms the condition of 'doubt' into the 'belief by considering practical effects should be highlighted, secondly, logical inference which makes us judge the observed result as a case of the general rule on the basis of resemblance should be highlighted, and thirdly, communities of inquiry which stand on the view of modest realism should be intended toward. These results could be expected in playing a role in critical discussion on science education relating to abduction.

• Korean journal of applied entomology
• /
• v.15 no.1 s.26
• /
• pp.7-16
• /
• 1976

In order to increase utility efficiency of red wood ants, Formica rufa truncicola var. yessonesis Forel as a resource of natural enemy of pine caterpillar, Dendrolimus spectabilis Butler, by finding out ecological and environmental factors in the habitat of red wood ants, the nest distribution and its density in habitat, plant distribution and density, stand-density of red pine, nest building and fixing plants, relative humidity of surface soil, physical and chemical natures of soil, and breeding rate were examined. The obtained results are summarized as follows: 1. The nest of red wood ants was densely distributed, in the lower-and middle top of mountain but no nest was found in the top. 2. The economical distribution of nest of habitat was estimated as $2.85/m^2$ and the lowest density as $1.93/m^2$ and these estimation lead us to confirm that pine caterpillar could be controlled. 3. The ecological characteristics of habitat seemed to be represented as higher stand-density of red pine of 10-20 years of age with large areas of eroded land under trees. The major grasses prevailing in this area were Andropogon brevifolius. Arundinella hirta, Miscanthus purpurasens, Eulia speciosa, Themeda japonica, Cymbopogon goeringii, and Eccoilpus cotulifer 4. Red wood ants seemed to build the nest by using red pine, Arundinella hirta, Miscanthus purpurascens, Themeda japonica or Cymbopogon goeringii as a fixing plant. 5. The limited point of humidity percent in habitat of red wood ants was estimated as $76\%$ during the acting period of May to September and as $72\%$ during pre-period of hibernation of October to November. 6. Soil analysis in habitating region showed higher concentration of organic matters and lower concentration of calcium and magnesium, and habitat was largely composed of silt and fine sand rather than coarse sand. 7. When the separated colony was transplanted to non-habitating red pine forest that seemed to have the similiar conditions as those of habitat, propagation and establishment of nest was possible.

• Journal of Forest and Environmental Science
• /
• v.17 no.1
• /
• pp.18-28
• /
• 2001

This study was carried out to investigate the characteristics of water quality variations by stand water balance in YangPyong-Gun Gejung-Lee small forest watershed. Water quantity. pH, $Cl^-$, $NO_3{^-}$, $SO_4{^{2-}}$, $Na^+$, $NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$ were monitored in open rainfall for one unit storm and long-term stream water in small forest watershed from January. 1998 to December. 1999. The results were summarized as follows: The runoff rate was 46.4% in 1998 and 52.2% in 1999. The average pH values of rainfall were 4.8 to 6.2 and those of stream water were 6.4 to 7.1 in small forest watershed. Total amount of input anion and cation values (kg/ha) in rainfall were $SO_4{^{2-}}>NO_3{^-}>Ca^{2+}>NH_4{^+}>Cl^->Na^+>K^+>Mg^{2+}$ and in stream water were $NO_3{^-}>Ca^{2+}>SO_4{^{2-}}>Na^+>Cl^->K^+>Mg^{2+}>NH_4{^+}$ in the order, respectively. The dissolved $NH_4{^+}$ was stored 5.29kg/ha and output of the other contents were more flow than input in small forest watershed.

• Journal of Korean Society of Forest Science
• /
• v.82 no.3
• /
• pp.235-245
• /
• 1993

This study was carried out to understand the stand structure based on the compositional characteristics of natural deciduous forest dominated by Quercus species, which will provide with fundamental ecological and silvicultural information for effective forest management. Of two tracts selected from the Seoul National University Research Forests, one is located in Kwangju-Gun Kyunggi-Do, and the other in Kwangyang-Gun Chollanam-Do. Point-quarter sampling method w-as employed to survey woody vegetation confined to larger than 6cm in DBH. The numbers of sample points were 152 and 187, in Kwangju-Gun and Kwangyang-Gun, respectively. Comparative analysis for two forest tracts was made as follows ; 1) species composition by calculation of importance values ; 2) number of stems per hectare for major tree species ; 3) species diversity for the forests in two locations ; 4) inter-species association based on $X^2$ test. The relative dominate of Quercus speices showed 88% at Kwangju-Gun, Kyunggi-Do and 50% at Kwangy-ang-Gun. Chollanam-Do. Such high dominance occurred due to high importance values of Quercus variahilis and Q. mortgolica in both locations. Quercus serrata showed low value at Kwangju-Gun. Kyunggi-Do whereas Q. acutissirna, Q. dentata and Q. aliena did none at Kwangyang-Gun. Chollanam-Do. The species diversity and evenness in oak communities exhibited 0.82 and 0.61, respectively at Kwangju-Gun. Kyunggi-Do, while those did 1.09 and 0.73 at Kwangyang-Gun, Chollanam-Do. Therefore, it was considered that Ku-angju-Gun region was disturbed severely by human activities but Kwangyang-Gun region eras less disturbed. Frequent appearance of Carpinus and Acer species indicates increase in diversities and better development of succession at Kwangyang-Gun region.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.3 no.4
• /
• pp.185-198
• /
• 2001

This study was conducted to reveal the effects of local climatic conditions on reproductive growth in a mature stand of Korean white pine based on climatic estimates. For this, the reproductive growth such as production and characteristics of cone and seed were first measured and summarized for seven years from 1974 to 1980. The local climatic conditions in the study site were also estimated by both a topoclimatological method and a spatial statistical technique. The local climatic conditions were then correlated with and regressed on the growth factors to reveal the relationships between the climatic estimates and the reproductive growth. Average number of conelet formation per tree showed highly negative correlation with some climatic variables related to minimum temperature in the year of flower bud differentiation. Especially, the most significant negative correlation were found between average of the minimum temperature for June and July of flower bud differentiation year and the number of conelet formation. There was no significant correlation between the number of cone production and climatic variables. However, total precipitation from December of the flowering year to February of the cone production year showed the most high correlation (r=0.6036) with the number of cone production. It was found that significant climatic variables affecting the amount of cone drop and cone drop percentage were the sum of cloudy days from June of the flowering year to August of the cone production year. Positive correlation was significantly recognized between the average weight of empty seed per cone and total precipitation from December of the flowering year to February of the cone production year. For the percentage of empty seed, five climatic variables among 19 variables were significantly correlated at 10% level. The average weight of a cone showed negative correlation with total precipitation from June of the flowering year to August of the cone production year. It was also found that average weight of a seed had highly negative correlation with total precipitation from December of the flowering year to February of the cone production year. The average weight of cone coat was negatively correlated with two climatic variables derived from clear days, which are sum of clear days from November of the flowering year to March of the cone production year and sum of clear days from December of the flowering year to February of the cone production year. On the other hand, it showed positive correlation with mean temperature of May in the flowering year. The exactly same results were obtained in correlation analysis for the percentage of cone coat.