• Korean Journal of Plant Resources
• /
• v.28 no.2
• /
• pp.253-258
• /
• 2015

In South Korea, Pinus pumila (Pall.) Regel (dwarf stone pine) has been designated as a critically endangered species by the Korea Forest Service. We have difficulties in obtaining the seeds of P. pumila because P. pumila grows only in the Daecheongbong area (1550–1700 m above sea level) of Mt. Seorak and almost all of its cones are damaged by birds and rodents. For establishing an ex situ conservation stand of P. pumila, this study was conducted to figure out the effects of wet cold (cold stratification, prechilling) and GA₃ treatment on the germination of P. pumila seeds. After cold stratification (1, 2, 3, 4, 5 months), prechilling (1, 2, 3, 4, 5 months) and GA₃ treatment (0, 100, 500, 1,000, 2,000, 3,000 ㎎/L), seeds were placed on petri-dishes at 25℃ under light condition. The percentage of germination, mean germination time and the germination rate were investigated. The results showed that both of the cold stratification and prechilling were effective in improving germination performances. However, there were no significant differences in performances between the two cold treatments. Within each treatment, the germination performances improved with the period of treatment. However, after three months of treatment, the performances showed no significant improvement. The gibberellin treatment was also effective in improving seed germination of P. pumila. The percentage of germination reached 79.0% in the seeds treated with 100 ㎎/L of GA₃. However, the germination performances decreased at high concentration of GA₃ treatments (over 2000 ㎎/L). In conclusion, cold stratification (over 3 months) or 100 ㎎/L of GA₃ treatment was considered to be the appropriate method for seedling production of P. pumila.

• Korean Journal of Ecology and Environment
• /
• v.51 no.4
• /
• pp.322-330
• /
• 2018

Herbivory is a major functional component of forest ecosystems, and herbivorous insects comprise about 25% of all insect species. Increasing plant diversity is related to herbivore abundance and diversity, which affects the level of leaf damage caused by insects. This study was conducted to identify plant-related variables such as plant diversity and number of leaves and density-related variables, basal area, and diameter at breast height (DBH) in a temperate forest of southern South Korea. To assess the level of leaf damage caused by leaf chewing insects, we set up two 0.1 ha plots in a temperate deciduous forest on Mt. Jirisan National Park. Plant richness differed between two sites: 16 species in 14 families(site 1) and 19 species in 15 families (site 2). Fisher's alpha index based on plant species richness and abundance resulted in 4.41 (site 1) and 6.57 (site 2). However, the sum of basal area of each site was higher in site 1 ($6.6m^2$) than site 2 ($3.7m^2$). The total surveyed leaves at two sites were 3,832 and 4,691, respectively and the damage leaves were 1,544 and 2,136, respectively. The mean leaf damage level was 11.2% (${\pm}1.76%$) in two study sites: the leaf damage level of the site 1 (11.99%) was significantly higher than site 2 (10.59%). Stepwise regression analysis showed that species diversity and evenness were the significant variables for leaf damages by chewing herbivores. NMDS ordination also identified that high tree density and low species diversity were the significant variables. This suggested that the level of damage was significantly higher in plots with low plant diversity and high tree density. In the future, we will investigate other guilds of herbivores such as sap-suckers, miners and gallers in temperate deciduous forests.

• Korean Journal of Breeding Science
• /
• v.50 no.4
• /
• pp.504-509
• /
• 2018

A new black barley variety, "Heuksoojeongchal," was developed as a cross between "Keunalbori 1" and "Masankwamaek/Mortoni" at the National Institute of Crop Science, RDA in 2014. Heuksoojeongchal had a longer culm length (89 cm) and a later average heading date and maturity than Seodunchalbori. It also had a spike length of 5.0 cm, $543spikes/m^2$, and 54 grains/spike. The 1000-grain weight of Heuksoojeongchal (36.0 g) was heavier than that of Seodunchalbori. Heuksoojeongchal showed resistance to barley yellow mosaic virus (BaYMV). The yield potential of Heuksoojeongchal was approximately 7% higher than that of Seodunchalbori upland, but the average yield potential was similar in upland and paddy fields. Among the quality characteristics, the ${\beta}-glucan$ content (6.7%) was higher and the amylose content (5.5%) was lower than those of Seodunchalbori. The whiteness of the black barley was low, and its absorption rate and spreadability were similar to those of Seodunchalbori.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.6
• /
• pp.459-463
• /
• 2001

Changes of rice yield and soil physicochemical properties of the dry-seeded rice-barley double cropping system were investigated for 10 years from 1990 to 1999. Generally, seedling stand was more unstable in the rice-barley cropping system regardless of barley straw addition or removal than in the rice single cultivation as indicated by higher standard deviation of seedling stand across year. Rice yield in rice-barley double cropping cultivation was increased due to barley straw application starting from the second year, recording 2 to 19％ increase (average of 9％ for 10 years) due to higher spikelet number. Protein content and Mg/K equivalent ratio were similiar among the barley straw applied field, rice single crop and barley straw removed plots. Also, amylose content was not significantly different among cropping patterns. Physicochemical properties of soil was improved by applying the barley straw; soil porosity was higher and content of organic matter and cation exchange capacity of Ca increased but those of Mg and K did not differ.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.42 no.4
• /
• pp.237-242
• /
• 2022

'Jogreen' (Secale cereal L.) was developed for rye cultivars not fast heading but winter hardiness with high yields, which was open-pollinated by ten rye cultivars including 'Chochun' in 1995. Its average heading date was April 15, which was five days earlier on average compared with 'Gogu'. At harvest, the plant height of 'Jogreen' was 117 cm which was taller than 'Gogu' as much as 6 cm. The number of stems was 983 per m², which was higher than that of Gogu (979). 'Jogreen' did not show both winter kill and powdery mildew, but showed lodging as 3 which is similar to 'Gogu'. The biomass in the dry weight base was 8.1 MT ha^-1, and showing was 4% higher than 'Gogu'. The crude protein content of 'Jogreen' was 11.9%, 0.8% lower than that of 'Gogu', and the acid detergent fiber (ADF) and the neutral detergent fiber (NDF) contents were 36.9% and 64.5%, respectively, higher than that of 'Gogu'. The total digestible nutrients (TDN) content also was low, but the TDN content was 5.09 ton ha^-1, which was higher than that of 'Gogu'. The seed productivity of 'Jogreen' was approximately 3.1 ton ha^-1, which was similar to the check. 'Jogreen' was found to be resistant to winter kill and can be adapted to after-paddy-rice cultivation in all Korean provinces. 'Jogreen' is likely to lodge, therefore, farmers should follow the recommended seeding rate and fertilization rate.

• Korean Journal of Environment and Ecology
• /
• v.38 no.3
• /
• pp.310-323
• /
• 2024

The purpose of this study was to understand the vegetation structure and ecological characteristic of Bulgapsan(Mt.) Provincial Park by setting up and surveying 64 plots(100m²). The analysis using the TWINSPAN and DCA techniques found seven community groups: Pinus densiflora-Quercus variabilis community, P. densiflora-P. rigida-Q. serrata community, Q. variabilis-Carpinus tschonoskii community, Q. aliena-Q. variabilis-Cornus controversa community, Q. aliena-Platycarya strobilacea community, Broad-leaved miced community and Q. variabilis community. The result of vegetation community structure analysis showed that P. densiflora community and deciduous Quercus spp. community were in competition, and succession to Quercus spp. community was expected. In the case of other broad-leaved forests, the current status is expected to be maintained. But continuous monitoring is required in areas where Neolitsea sericea and Cephalotaxus appear, which grow naturally in warm temperate forest and southern temperate vegetation zone. Species diversity by communities are confirmed to be highest at 2.6654 in the actively competitive P. densiflora-P. rigida-Q. serrata community, and the lowest in the Deciduous broad-leaved forests community at 1.2548. The results of the tree rings and annual growth analysis showed that dominant trees had an average age of more than 37~87 years. Among them, N. sericea designated as a natural monument was 48~56 years old.

• The Korean Journal of Zoology
• /
• v.20 no.1
• /
• pp.29-40
• /
• 1977

The authors examined fresh-water gammarid materials which were collected from streams in 20 localities of South Korea during the period from 1965 to 1977. As the results of the observation, the authors have concluded as follows: 1. These fresh-water gammarids belong to Gammarus pulex-group and are distributed widely in mountain-streams of mainland and surrounding islands of South Korea. 2. The present specimens are different from the subspecies, G. pulex koreanus Ueno, 1940 which was described originally from North Korea. In the latter, the pulmose setae of third uropod are limited only to the outer margin of both rami. The peduncle and flagellum of second antenna are fringed with a few short setae and the flagellum is provided with calceoli. In the former, both margins of inner ramus and outer margin of outer ramus of third uropod are fringed with long pulmose setae. The peduncle and flagellum of second antenna have abundant relatively long setase and the flagellum is not provided with calceoli. 3. The present specimens are different from the subspecies, G. pulex sobaegensis Ueno, 1966 which was described originally from South Korea. The latter dwells in cave, while the former dwells in mountain-stream. In the former, the arrangements of pulmose setae of third uropod and the setation of second antenna are similar to those of the latter. But they are quite different from each other in several characters such as shape of upper lip, shape of fifth article of second gnathopod and numbers of incisions on front distal margins of coxal plates 1-3. The former has spines on surface of coxal plates 1-3, but the latter has not. In females, the former has four pairs of marsupial plates, while the latter has three pairs. 4. The present materials show local variations. Therefore, they could be divided into 3 local groups. The first group (specimens from Mt. Odae and Mt. Sogeumgang) has pulmose setae on the both margins of both rami of third uropod and second article of outer ramus is relatively long. In general, this group has setae sparsely on the both rami and especially a few setae on the outer margin of outer ramus. The second group, which are widely distributed in South Korea, has pulmose setae on the both margins of inner ramus and on the outer margin of outer ramus of third uropod. In the third group (specimens from Mt. Soyo), the pulmose setation of third uropod is similar to that of the first group, but the second article of outer ramus is very small.

• Korean Journal of Plant Resources
• /
• v.10 no.2
• /
• pp.175-182
• /
• 1997

This study was carried out to investigate the effect of several organic fertilizers on the growth characteristics, root yield and the levels of the efficacious constitutents saikosaponins in Bupleurum falcatum L. in the field of Chonnam RDA. Naju, 1994. Five organic fertilizers were used ; rice straw manure(RSM), rice straw(byproduct of mushroom)manure[RS(BM)M], pig-dropping sawdust manure(PSM),poultry manure(PM)and sawdust(byproduct of mushroom) manure[S(BM)M]. The results were summarized as follows ; The chemical properties, such as organic matter, available phosphate, $K_2O$, CaO, and MgO of soil were increased on all plots with the addition of organic fertilizers, specifically in PM+RS(BM)M application. PM+RS(BM)M treatment was higher in emergence rate and better in the growth charaters of shoot, root parts of plants than those of conventional fertilization and the highest dried root yield resulted from using 39% PM+RS(BM)M treatment. Thus, the organic constituents of the plant leaves were affected in the same ways by all treatments, but the T-N, $P_2O_5$, $K_2O$, CaO and MgO contents of the roots were highly increased in PM+RS(BM)M treatment, also the total saikosaponin levels in the roots increased with different organic fertilizers in the following order : 1.70% in PM+RS(BM) treatment, 1.66% in RS(BM) treatment, and 1.57% in RSM+N-P-K treatment. There were significant positive correlation observed between the growth characters of shoot, root parts of plants, yield and contents of T-N, $P_2O_5$, $K_2O$, total-saikosaponin in B. falcatum roots.

• Ocean and Polar Research
• /
• v.36 no.1
• /
• pp.13-24
• /
• 2014

We established the first complete ice core processing method and analytical procedures for fundamental proxies, using a 40.2 m long ice core drilled on the Mt. Tsambagarav glacier in the Mongolian Altai mountains in July 2008. The whole core was first divided into two sub ice core sections and the measurements of the visual stratigraphy and electrical conductivity were performed on the surface of these sub core sections. A continuous sequence of samples was then prepared for chemical analyses (stable isotope ratios of oxygen ($^{18}O/^{16}O$) and hydrogen ($^2H/^1H$), soluble ions and trace elements). A total of 29 insoluble dust layers were identified from the measurement of visual stratigraphy. The electrical conductivity measurement (ECM) shows 11 peaks with the current more than 0.8 ${\mu}A$ Comparing the profiles of $SO_4{^{2-}}$ and $Cl^-$ concentrations to correlate with known volcanic eruptions, the first two ECM peaks appear to be linked to the eruptions (January and June 2007) of Kliuchevskoi volcano on the Kamchatka Peninsula of Russia, which supports the reliability of our ECM data. Finally, the composition of stable isotopes (${\delta}^{18}O$ and ${\delta}D$) shows a well-defined seasonal variation, suggesting that various chemical proxies may have been well preserved in the successive ice layers of Tsambagarav ice core. Our ice core processing method and analytical procedures for fundamental proxies are expected to be used for paleoclimate and paleoenvironmental studies from polar and alpine ice cores.

• Journal of Korean Society of Forest Science
• /
• v.107 no.3
• /
• pp.237-244
• /
• 2018

This study was carried out in order to secure basic data of seedling mass propagation technique of Rhododendron mucronulatum which is the native tree species of Korea by surveying the characteristics of its fruit and seed. The fruits were collected at Mt. Goryeo in Ganghwa-gun on different dates in 2013; August 26th, September 5th, September 12th, October 4th. The seed germination test was carried out at 5, 10, 15, 20, 25 and $30^{\circ}C$. Moisture content of the fruit was highest (54.5%) in the fruit collected on September 5th. Number of the seeds in a fruit was 91.3 to 116.3, regardless of the collection date. Seed length was highest ($1947.4{\mu}m$) in the seeds collected on October 4th and seed width was highest ($727.3{\mu}m$) in the seeds collected on September 12th. Germination rate of the seeds was highest at $25^{\circ}C$ regardless of the seed collection date, which showed the highest value(27.3%) in the seeds collected September 12th. Meanwhile, the seeds were not germinated not at all at 5, 10 and $30^{\circ}C$. $T_{50}$ and mean germination time of the seeds got shorter at the higher temperature. Germination uniformity got lower when the collection date got later. Germination speed of the seeds was fastest at $25^{\circ}C$. According to the results of this study, it seems that the appropriate time to collect fruit and seed is between September 12th and October 4th, and the appropriate temperature for the seed germination is $25^{\circ}C$.