• The Korean Journal of Ecology
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• v.22 no.6
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• pp.349-354
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• 1999

The spatial distributions of allelic frequencies and ecological traits by randomization were studied in the natural population of two species (Pinus rigida and Pyrola japonica). Both species showed significant positive spatial autocorrelation as measured by Moran's I. In P. rigida, the genetic similarity was shown in individuals within up to a scale of 18 m distance and this is partly due to combination of pollen and seed dispersal by wind or men. In P. japonica, significant spatial autocorrelation was consisted of a scale of 8 m intervals. These population structure in the distribution of allelic frequencies is related to mating systems such as outcrossing and vegetative spread. The results also indicate that positive species associations between P. rigida and P. japonica can occur when both species select the same habitat or require the same environmental conditions.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.251-257
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• 2010

Influences of environment (indicated by plant associations) and forest management practices on the distribution of Armillaria spp. and genets (vegetative clones) were investigated. A total of 142 isolates of Armillaria was collected from various host trees on pristine and managed sites (thinned and/or fertilized) growing in relatively wet and dry environments in eastern Washington, U.S.A. The incidence of Armillaria spp. was significantly higher in the relatively wetter sites than the relatively drier sites, as indicated by plant associations. However, no differences in Armillaria occurrence were found among different forest management practices (control vs. thinned vs. thinned and fertilized) within both wetter and drier sites. Incidence of Armillaria was significantly different among conifer and shrub species. The highest proportion with Armillaria was found on grand fir (Abies grandis). Based on pairing tests and rDNA sequencing, the 142 isolates were comprised in a total of 20 genets representing three Armillaria species. More diverse Armillaria spp. were found in both relatively wetter and relatively drier sites within the undisturbed control plots, compared to plots disturbed by forest management practices. The results from this study provide baseline information toward understanding how environment and forest management practices influence incidence and diversity of Armillaria species and genets.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.90-95
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• 1998

Symbiotic associations between land plants and fungi have been known for more than one hundred years. Vesiculararbuscular mycorrhizas (VAM) are the most common symbiosis in flowering plants and can be recognized in almost all plant families. These fungal associations play a very important role in the growth and survival of plant species. However, with respect to the importance and intensity of the VAM, there is great variation among host species. Our knowledge of the VAM fungus-plant association in Araliaceae is very limited. After the first reports of the occurence of VAM in lateral roots of Panax species, mycorrhizal structures are now described as special structures representing the so-called Paris type. In this type, the development of new spores and vesicles is extremely low. This and the type of colonization of the fungus in Panax roots indicates on, one hand, the high intensity of the VAM and, on the other hand, a remarkable dependency for VAM in members of the Panax species. Therefore, it can be easily understood that cultivated Panax plants exhibit a significant uptake of nutrients and this leads to an extremely depleted soil at harvest. Further, the soil is nearly free of the spores of VAM fungi as they germinate each year on the newly developing Panax roots.

• 한국석유지질학회:학술대회논문집
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• spring
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• pp.1-11
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• 1997

Thirty one samples from Late Cretaceous and Tertiary interval sections (468-783m) of the Kachi-I Well in Block II, Yellow Sea Basin, have been analysed for their terrestrially derived palynofloras. The systematic study of the palynomorphs recovered has yielded one hundred and fifty-five taxa; forty-three species of spores belonging to twenty-eight genera, seventy-seven pollen assignable to forty-three genera, and twenty-seven species assignable to fifteen genera and eight fungal remains. The results of both qualitative and quantitative analysis propose a succession of eight terrestrial palynomorph associations. Seven associations are erected in Late Maastrichtian and one in Early to Middle Miocene. Age determinations are on the basis of palynomorph taxa alone for the all associations. The Late Cretaceous/Tertiary unconformity is recognised at between 603 and 613m, based on the palynological data. The sedimentary basin during the Late Cretaceous seem to be lowland shallow marginal lacustrine with stagnant, mesotrophic conditions. On the other hand, the basin during the Early-Middle Miocene is considered to have been characterised by lowland swamp areas. The palaeoclimatic conditions during the Late Cretaceous are considered to be humid tropical to subtropical, while during the Early to Middle Miocene they are considered to be warm temperate with humid conditions. A comparison of palynomorph assemblages between the present study and the previous studies of Late Cretaceous in Circum-Pacific Northern Hemisphere is made, These assemblages reveal that lower sections (612-783m) of the Kachi-I well belong to the Late Cretaceous Aquilapollenites province of Herngreen and Chlonova (1981) and Srivastava (1981, 1994).

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.67-77
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• 2010

Stand structure and spatial associations of the dominant tree species in Quercus mongolica stands were investigated to understand interspecific relationships and the persistent dominance of Q. mongolica. We examined the species composition, DBH (diameter at breast height) distribution, and spatial distribution of trees (${\geq}\;2.5\;cm$ DBH) in two permanent $100\;m\;{\times}\;100\;m$ plots in Q. mongolica-dominant stands on the western part of Mt. Jiri. Ripley's K-function was used to characterize the spatial patterns and associations of dominant tree species. Q. mongolica showed a continuous and reverse-J shaped DBH distribution with clumped spatial distribution in both study sites. Q. mongolica and Abies koreana exhibited a negative association implying potential interspecific competition. The positive spatial association between Q. mongolica and Alnus hirsuta var. sibirica and Fraxinus sieboldiana were affected by site characteristics: limited habitat conditions with a large proportion of rock surface. Our results suggest that interactions among species were complex and ranged from positive to negative. Differences in stand and site characteristics and regeneration mechanisms among the species play an important role in regulating their spatial distribution patterns, while competition between individuals also contributes to spatial patterning of these communities. The high density and the early developmental stage of spatial distribution and structural characteristics of Q. mongolica and the relatively low importance values of other species in the stands imply that Q. mongolica will remain dominant in the study sites in the near future.

• Animal Systematics, Evolution and Diversity
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• v.13 no.2
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• pp.141-172
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• 1997

Six phytal harpacticoid species of the genus porcellidium are recorded from 22 algal species in the eastern (Sea of Japan) and southern (Korea Strait) coast of Korea. Among these six species, Porcellidium ofunatense Harris and Iwasaki and Porcellidium gamoi(Harris and Iwasaki) are recorded as new to Korean fauna. Other four species are described as new to science: Porcellidium bipartitum n. sp. found from a single algal species, Procellidium wandoensis n. sp. from ten algal species, Porcellidium acutum n. sp. from five algal species, and Porcellidium brevlcacum n. sp. from two algal species. It is found that the associations between the species of Porcellidium and macroalgae reveal weak specificities.

• Animal Systematics, Evolution and Diversity
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• v.8 no.1
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• pp.57-68
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• 1992

Only four copepod species associated with sea stars have beenknown from the north Pacific . The examination of Korean sea stars for copepod associates revealed two species ; Scottomyzson gibberum and a new species belonging to the genus Synstellicola. Both species are (re) described. S. gibberum , A sole member of the genus hitherto known only from the northeastern Atlantic , is recorded in this report to be associated with various sea stars and distributed widely in Korean seas.

• The Korean Journal of Mycology
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• v.51 no.2
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• pp.121-125
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• 2023

In this study, we examined the ectomycorrhiza (ECM) formed by a species of the genus Tuber, T. koreanum, with two indigenous Korean oak species, Quercus acutissima and Q. dentata. T. koreanum showed a high colonization rate for both oak species, with a higher mean colonization rate observed for Q. acutissima. The mycorrhizal characteristics of T. koreanum were described, revealing distinct morphological and anatomical differences between the ECM formed with the two host plants. This study is significant because it is the first to elucidate ECM formations of T. koreanum in indigenous oak trees. However, further studies are required to differentiate the ECM associations formed by T. koreanum from those of other Tuber species.

• Journal of Plant Biology
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• v.9 no.1_2
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• pp.7-16
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• 1966

In order to determine the factors related to site quality, 13 areas of Larch growing in the Kwangung and its vicinity forest as sample plots, were examined. Sample plots included various site classes as well as age classes. Three were divided into two groups (major and minor trees). Average height of dominant trees was determined through messurement of 5 to 6 dominant tree in each sample plots. Average height of dominant 30 year-old trees was the basis for site index. A Standard Yield Table for the larch produced in Kwangnung forest was made by various data, which included age class 5, ranging from 10 to 45 years. The relationship of the height of the trees, the site conditions, and ground vegetation are investigated in this paper. The site indexes of 40 forest class age in 28-B and 28-G forest classes of the larch associations for ground vegetation had comparatively rarge differences due to the sampled areas. The relation of the direction of forest communities to the height and the diameter of the tree shwoed that its communiteis of northest and northwest parts appeared higher valueof the height and the diameter. The diameter and the height of trees were closely realted to each other. The samller the occupied area per tree and the smaller the average distance among trees, the more density was increased. The larger the density was the lower height of the trees. In the ground vegetation of the larch communities, there seems to be a definite correlation between the height of trees and the occupied area per tree or the average distance among the trees. The height of trees and site index of two larch communities were as follow: 28-B forest class site index 20.8, height 24.0m, 28-G forest class site index 18.4, height 20.9m. The ground layer was analyzed by the method of Quadrat(20/20sq. cm) with an interval of 1M. It set up 40 Quadrats of the larch communiteis. The community structure of the ground vegetation of two larch was analyzed, and important value was calculated and then evaluated. The ground vegetation under the larch had developed Burmannii Beauv stratal society below the 28-B and 28-G the forest class. Accordingly, the first important value of Burmannii Beauv was found in two ground vegetation below the larch. Therefore, this species could be quantitatively considered as the forest indicator species. Common species of each community appeared 18 species out of 34 species in the ground vegetation under two larch communities. The ground vegetation of the 28-B forest class showed more than that of the 28-G forest class. the similarity of the ground vegetation was measrued by the Frequency Index Community Coefficient. The differences between the associations were lcearly manifested by the ground vegetation tested by Gleason's Frequency Index of Community Coefficient for the analysis of each stratal society of all associations. According to F.I.C.C. the ground vegetation under two larch(28-B and 28-G) forest classes showed higher value. An investigation into the relationship of physical and chemical properties of soil and site was considered the next step to be taken in the study of the larch site classification.

• Asian Journal of Turfgrass Science
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• v.9 no.4
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• pp.317-329
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• 1995

The study of standing crop of the ground vegetation under the coniferous stands was pursuited in regard of soil nutrients at Kwangnung plantation from May to Octoher, 1971 and 1991. The coniferous stands implied pine and larch associations of which the young stands of each as-sociation were 9~12 years and the older one 40~70 years. The larch stands were more plentiful in species than in the pine stands and the Festuca ovina and Oplismenus burmannii each were dominant species of pine and larch stands. The standing crop of pine stands is from 98.02g /$m^2$ to 385.32g /$m^2$ The standing crops of those stands showed great increase from June to August when the air temperature and rainfall were fairly high. The standing crop has correlation to total nitrogen and organic matter in the soil.