• Weed & Turfgrass Science
• /
• 제4권4호
• /
• pp.338-347
• /
• 2015

Reinforcement cells are used to aid grass growth and taken together, this serves to extend greenery beyond the conventional spaces of lawns, tree pits, gardens, and parks, and is advantageous to urban cities since space for greening is often limited. Drought has variable effects on plant life and the resilience of turf to drought resistance also varies with species. Changes in photosynthetic ability were more pronounced for media rather than grass species. The media of sand without organic matter was found to be least suited for drought resistance. Normalized difference vegetation index (NDVI) and digital image analysis (DIA) data were generally in favour of Zoysia species as oppose to A. compressus. In A. compressus, selective traits such as, a more extensive root system and lower specific leaf area (SLA) were not an underlying factor that assisted this grass with enhanced drought resistance. Generally, WUE was found to be strongly related to plant characterises such as overall biomass, photosynthetic features as well as the lushness indexes, and specific leaf area. This study found a strong relationship between WUE and a suite of plant characteristics. These traits should serve as useful selection criteria for species with the ability to resist water stress.

• 한국산림과학회지
• /
• 제95권5호
• /
• pp.595-600
• /
• 2006

The plot design influences the budgets and the precision of forest inventory results. The objective of this study is to determine the efficiency of estimating forest variables such as tree density, basal area, volume, and species richness based on various plot sizes using fixed-area plot sampling in the natural deciduous forest of Pyeong-Chang County, Gang-won Province, Korea. In this study, 108 reference plots were established with a fixed plot size and shape of 0.09 ha ($30m{\times}30m$). In order to determine the optimal plot size for the interest of variables, each sample plot was established using different shapes (square, circle, and rectangle) and was divided into different plot sizes from 100 to $900m^2$. The mean relative difference (MRD) for the sum of the basal area and volume, and tree density per hectare decreased as plot size increased. But the MRD for three variables were only below 13% at the plot size of $500m^2$. Species richness for each reference stand observed ranging from 2 to 15 species, demonstrated highly positive significant relationships with plot size. The minimum plot size for the estimation of tree density, the sum of the BA and volume was determined to be about $400m^2$, whereas the estimation of species richness required a minimum plot size of $500m^2$.

• Parasites, Hosts and Diseases
• /
• 제21권1호
• /
• pp.118-124
• /
• 1983

The distribution, external morphology, radula, chromosome numbers of Planorbidae snails were studied. 1. The specimens were collected at four stations in Nonsangun, Kongjugun, and Daedukgun which are located around Geum river. Three genera and three species of Planorbidae, Hippeutis cantorir Segmentina hemisphaerula and Gyraulus cenvexiusculus, were collected. H. cantori was the most abundant species among the three species. G. convexiusculus was the least abundant one. 2. Each species could be identified on the basis of its external characteristic, since the periphery of each species has a peculiar shape. H. cantori was the largest one among the three species. 3. The radula formula of each species was very similar to other species. The size of radula was proportional to the size of shell. The radula formulae of H. cantori, S. hemisphaerula, and G. convexiusculus were 29 : 1 : 29, 23 : 1 : 23, and 16 : 1 : 16 respectively. The difference of radula formula could be found in the total numbers of laternal and marginal teeth. 4. The haploid chromosome number of H. cantori was eighteen (n=18), S. hemisphaerula and G. convesiusculus were assumed to be same in their chromosome numbers (n: 18).

• Journal of Species Research
• /
• 제6권spc호
• /
• pp.38-50
• /
• 2017

This study describes a new species of cytheroid ostracod, Paradoxostoma koreana sp. nov., collected in Korea. In addition, three other cytheroid ostracods, P. setoense Schornikov, 1975, Loxoconcha pulchra Ishizaki, 1968, and Ishizakiella miurensis (Hanai, 1957), are reported with brief descriptions and images. Paradoxostoma setoense and L. pulchra were previously only known from Japan, while I. miurensis was previously reported from Korea. Here, we describe variability in hemipenis morphology observed in the Korean population. The new species is closely related to several East Asian species, but its sister species is P. rhomboideum Okubo, 1977. The primary difference between the new species and P. rhomboideum is morphology of the distal projections of the hemipenis, but minor differences exist in the details of the cheatotaxy of other appendages. This report also provides a list of all East Asian Paradoxostomatidae.

• 한국산림과학회지
• /
• 제4권1호
• /
• pp.39-41
• /
• 1965

(1) The durability of fifteen species of hard woods grown in Kangwon-do in relation to Polystictus Versecolor L. Fr. and Irpex consors Berk was studied. (2) The least affected hard wood species by Polystutus Versecolor L. Fr. were Q. serrata, C. crenata, M. amurensis, F. rhynchophylla and J. mandschrica; the moderatly affected species were Q. Variabilis, U. Davidiana var japonica, B. latiforia, C. controversa, P. padus and A. mono; and the most highly affected species were P. serrulata var. spondanea, S. obassia, T. amurensis and B. schmidtii. The least affected hard wood species by Irpex consors Berk, were U. Davidiana var japonica, C. crenata, M. amurensis, F. rhynchophylla, and J. mandshurica; the moderatly affected species were Q. Valiabilis, Q. serrata, P. serrulata var. spondanea, C. controversa, and A. mono; and the most highly affected species were B. latiforia, P. padus, S. obassia, T. amurensis, and J-mandshurica. (3) No difference was obscured on the durabilities on effected by kind of fungus. (4) Correlationship between specific gravity and durability of the woods was not significant.

• 한국자원식물학회지
• /
• 제28권3호
• /
• pp.357-362
• /
• 2015

Carbohydrate sources are one of important factors associated with macro- and micro nutrients and phytohormones in vitro culture medium for shoot growth. The optimal carbohydrates for eight species of the genus Prunus which are economically important fruit crop was evaluated at the initiation and elongation stages. All carbohydrate seemed utilized for the bud break and leaf growth at the early stage of culture. However, shoot elongation and fresh weight of species tested were superior in the medium containing 90 mM of fructose or glucose rather than sucrose. There was no difference between glucose and fructose. Adventitious shoots from the axillary buds were induced in most species but no significant differences were observed except for two species (P. salicina ‘Shiro’ and P. tomentosa). These result demonstrated that glucose and fructose were suitable carbohydrate sources for diverse Prunus species than sucrose, although the response to the carbohydrates in the medium were slightly different in the species.

• The Korean Journal of Ecology
• /
• 제17권1호
• /
• pp.11-22
• /
• 1994

전북 완주군 상관면 죽림리에 위치한 편백 식재림의 하중식생은 식재림 외부보다 출현종수 및 개체수가 매우 적으며, 인공림내에서도 순편백림이 편백-일본잎갈나무림보다 더 적다. 빈도 10% 이상인 종은 109종류 중에서 27종 뿐이었고, 청가시덩굴과 청미래덩굴의 빈도가 가장 높았다. 식재림내의 지표면 조도와 토양을 분석한 결과, 광량의 부족과 토양의 낮은 pH, 그리고 토양 무기물의 차이가 빈약한 하충식생의 원인으로 추정되었다. 그리고 종에 따라 다르나 토양을 이용한 실험실에서의 생물정량으로 임외종의 발아와 신장 생장이 더 억제되는 경향을 보였고, 편백 litter 추출액과 leachate에 의한 생물정량에서도 임외종의 발아와 신장생장이 억제되는 경향을 보였다. 따라서 litter와 leachate를 통한 편백의 allelopathy 효과가 적어도 부분적으로나마 본 식재림의 빈약한 하중식생의 한 원인이 될 수 있을 것으로 사료된다.

• 한국초등과학교육학회지:초등과학교육
• /
• 제32권3호
• /
• pp.346-360
• /
• 2013

The purpose of this study was to develop a multimedia game program as a strategy for teaching alien species and to examine the effect of the program on recognition, motivation and achievement about alien species. In order to find the effect of developed program, 62 students among 6th graders at S Elementary School located in Gyeonggi-do were divided into two groups. Lesson with multimedia game was given to the experimental group, and the control group received traditional lesson. The results were as follows. First, the experimental and control groups showed significant difference in recognition of alien species. Second, the two groups showed statistically significant difference in learning motivation. For the subdomains of the recognition, significant results were obtained at the significance in attentiveness, relevance, confidence and satisfaction. Third, the two groups showed significant difference in academic achievement. Lastly as a result of interviewing subjects of the experimental group about lesson based on game, subjects generally had positive opinions that the new learning method is interesting and has helpful influence on the lesson.

• 아시안잔디학회지
• /
• 제25권2호
• /
• pp.195-201
• /
• 2011

해조추출물과 2종의 키토산 제형을 뗏장잔디 생산농장에서 가을철에 creeping bentrgass (Agrostis palustris Huds) Penn-A1 품종과 Kentucky bluegrass (Poa pratensis L.) 혼용품종(Midnight 33%, Moonlight 33%, Prosperity 33%)에 살포하였다. 잔디 질에 미치는 잔디 잎색, 엽록소함량 및 NDVI을 조사하였다. 키토산과 해조추출물 처리는 엽록소 함량과 잔디생장에서 유의성 있게 증가하였다. Kentucky bluegrass 종의 혼용품종과 creeping bentrgass 종의 Penn-A1 품종의 잔디에 엽록소 함량과 잔디생장이 키토산 제형 과 해조추출물의 엽면시비에 의해 유의성 있게 증가하였다. 잔디의 잎색은 유의성이 없었다. 이들 결과는 키토산 제형과 해조추출물이 가을철 골프장에 잔디관리에 도움이 될 것으로 생각한다.

• Journal of Periodontal and Implant Science
• /
• 제48권1호
• /
• pp.12-21
• /
• 2018

Purpose: The goal of this study was to develop and validate a standardized in vitro pathogenic biofilm attached onto saliva-coated surfaces. Methods: Fusobacterium nucleatum (F. nucleatum) and Porphyromonas gingivalis (P. gingivalis) strains were grown under anaerobic conditions as single species and in dual-species cultures. Initially, the bacterial biomass was evaluated at 24 and 48 hours to determine the optimal timing for the adhesion phase onto saliva-coated polystyrene surfaces. Thereafter, biofilm development was assessed over time by crystal violet staining and scanning electron microscopy. Results: The data showed no significant difference in the overall biomass after 48 hours for P. gingivalis in single- and dual-species conditions. After adhesion, P. gingivalis in single- and dual-species biofilms accumulated a substantially higher biomass after 7 days of incubation than after 3 days, but no significant difference was found between 5 and 7 days. Although the biomass of the F. nucleatum biofilm was higher at 3 days, no difference was found at 3, 5, or 7 days of incubation. Conclusions: Polystyrene substrates from well plates work as a standard surface and provide reproducible results for in vitro biofilm models. Our biofilm model could serve as a reference point for studies investigating biofilms on different surfaces.