• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.2
• /
• pp.121-129
• /
• 2014

Marine algal flora and community structure were seasonally investigated at four sites in the vicinity of the Igidae on the southern east coast of Korea from May 2010 to February 2011. A total of 66 species including 9 of Chlorophyta, 14 of Phaeophyta, 43 of Rhodophyta were found during the survey period. Among these species, 16 species were found throughout the year. Seasonal mean biomass in wet weight was 123.6 (spring), 2,061.6 (summer), 412.0 (autumn), 678.9 (winter) $g{\cdot}m^{-2}$. Maximum biomass was recorded in summer($2,061.6g{\cdot}m^{-2}$), and minimum was recorded in spring($123.6g{\cdot}m^{-2}$). Spatial maximum and minimum species number were recorded at station 3 and 4(50 species) and at station 1(47 species). At station 1, 2 directly exposure on Yongho and Daeyeon cheon (stream) run off, and discharge from Nambu sewage treatment plants near coastal area, species diversity was relatively low and dominant species were similar throughout four seasons. The R/P, C/P and (R+C)/P value reflecting flora characteristics were 3.07, 0.64 and 3.71, respectively. The flora investigated could be classified into six functional groups such as coarsely branch form 39.39 %, sheet form 30.30 %, thick leather form 13.64 %, filamentous form 12.12 %, crustose form 3.03% and jointed calcareous form 1.52 % during survey period. The number of marine algae species in Igidea were 96 species at 1996 to 1997 and 66 species at 2010 to 2011, respectively. The change of seaweed species is due to the pollution loaded from sewage treatment plant and stream. We thus recommend that the positive maintenance control method like sewage treatment, for the protection of seaweed bed should be proceeded to near coastal area.

• Journal of Korean Society of Forest Science
• /
• v.81 no.4
• /
• pp.310-319
• /
• 1992

Vegetational data obtained from 24 quadrats of Mt. Paekdu area were analysed by applying two multivariate methods : two-way indicator species analysis(TWIMSPAN) for classification and detrended canonical correspondence analysis(DCCA) for ordination. DCCA technique allowed to extract the ordination axes that could be related to 9 environmental factors. The dominant tree species distributed in the region between 1,700-1,950m from sea level were Betula ermanii, Larix olgensis, Abies nephrolepis, and Picea jezoensis in descending order. The dominant tree species distributed in the region between 1.300-1.500m were Abies nephrolepis, Pinus koraiensis, Larix olgensis, Betula mandshurica, and Picea jezoensis in descending order. The available phosphorus content in forest soil ranged from 7 to 1.153ppm. The distribution of the major communities showed a close relationship with elevation gradient. From high to low elevation, the communities of Alnus fruticosa var. mandshurica, Betula ermanii, Larix olgensis, Abies nephrolepis, Picea jezoensis, Pinus koraiensis, and Quercus mongolica were found in descending order. At the communities where Betula ermanii was dominant, Betula ermanii forest was distributed in the high elevation area, Betula ermanii-Larix olgensis forest in the good nutrition of organic matter and $K^+$, and Abies nephrolepis forest in the good nutrition of $Mg^{{+}{+}}$ and $Ca^{{+}{+}}$. The most dominant factor influencing community distribution was elevation.

• Korean journal of applied entomology
• /
• v.34 no.3
• /
• pp.256-265
• /
• 1995

The effect ground-cover weeds on the occurrence of apple pests and their natural enemies was studied in an apple orchard in Ahnsung, Kyung-gi do during seasons of 1993 and 1994. The major apple pests and their parasitoids and predators were surveyed on the apple tree canopy in tow experimental plots; a weed-free lot where all weeds were removed by herbicide treatment, and a mowed plot where weeds were allowed restrictly by cutting with an asickle. Also, a sweep net sampling was taken from ground-cover weeds in the mowed plot. There were no significant differences in the abundance of mite and aphids between two plots, although mite densities tend to be lower in the mowed plot. The apple leaf miner, Phyllonorycter ringoniella, was significantly fewer in the mowed plot,. The densities of natural enemies of mites and aphids were slightly higher in the mowed plot. The parasitism of apple leaf miner in the mowed plot was 6~10% and 20~25% higher than that in the weed-free plot in 1993 and 994, respectively. Several natural enemies such as Apanteles kuwayamai (Braconidae), Orius sauteri (Anthocoridae), Chrysopa sp. (Chrysopidae), coccinellidae, and Eulophidae were collected both from weeds and the apple trees, However, potential apple pests were not observed on weeds. The development of insect community on the apple tree canopy was restricted by the pesticide spray on apple trees, while the insect community on weeds was maintained without significant destruction by pesticides spray on apple trees. Consequentely, the ground-cover weeds under apple trees affected occurrences of apple pests and their natural enemies in apple trees. te specialist natural enemies such as apple leaf miner's parasitoids dispersed from weeds to the apple canopy and affected apple leaf miner density significantly. However, generalist predators that have preys available on weeds stayed on weeds, hence their control effects for mites and aphids on the apple canopy were low.

• Journal of Korean Society of Forest Science
• /
• v.96 no.6
• /
• pp.730-736
• /
• 2007

The heterogeneity of forest environment plays an important role in the structure and dynamics of tree population, the composition of forest community, and the maintenance of species diversity. Based upon the research data of the nine hectare permanent plot in the typical mixed broadleaved-Korean pine forest, this study was conducted to analyze the characteristics of spatial pattern of Acer tegmentosum population for seedlings, saplings, and living and dead trees so as to evaluate the effect of micro-topography on spatial pattern of the species. The results noted that A. tegmentosum preferred to gentle slopes. There was no difference in density of seedlings by the variation of aspect, but the density of saplings, and living and dead trees was high on the western and southeastern slopes. Living trees of A. tegmentosum showed the clumped pattern for all scales within 150 m and highest at the scale of 30 m. Dead stems of the species indicated the clumped pattern within 111 m, highest at the scale of 72 m, and random pattern beyond the scale of 111 m (P < 0.01 ). The similarity of occurrence by developmental stages of A. tegmentosum showed that seedlings vs. saplings, saplings vs. living trees, and living trees vs. dead stems had highly positive correlation to each other, respectively (P < 0.01 ), indicating that the occurrence of previous developmental stages was positively correlated to following stages.

• Journal of Wetlands Research
• /
• v.14 no.4
• /
• pp.667-674
• /
• 2012

This study was conducted to understand landscape ecological characteristics on habitats of Nannophya pygmaea, an endangered species in South Korea. The ecological characteristics of the habitats were investigated in abandoned paddy fields where N. pygmaea populations have been found in Chungcheongnam-do Kongju, Gyeonggi-do Kwangju and Gyeongsangbuk-do Mungyeong from 2009 to 2010. We surveyed the dominant vegetation, areas, water depth and temperature, and plant height and coverage to compare the wetlands living N. pygmaea and not living N. pygmaea. As a result, habitats of N. pygmaea in all regions were dominated by Salix koreensis community. There is no signigicant difference in the water temperature, plant height and coverage among wetlands of the three different sites, but depth was varied within 2.5~9.5cm. The water depth of habitat was deeper in Gongju than the others. Percentage of open water was 1.7~6% in the wetlands living N. pygmaea. but it did not appear in the wetlands not living N. pygmaea. Therefore, the ecological characteristics of wetlands as abandoned paddy fields should be taken into account for N. pygmaea habitat conservation and restoration.

• Korean Journal of Environmental Agriculture
• /
• v.22 no.2
• /
• pp.153-165
• /
• 2003

This study was conducted to get some information on plants abilities to enhance water purification and to find out away to conserve the ecosystem in Mankyeong river. Vegetation were surveyed at 4 sites pointing by 1:5,000 topographical map, from June 2001 through March 2002. T-N content in water were high in all sites of Mankyeong river, the average T-N levels were 8.59 and 17.23 mg/L, summer and winter, respectively. The average T-P level during summer was 0.47 mg/L but that was 1.79 mg/L during winter. The BOD level in Mankyeong upstream ranged from 0.95 to 2.57 mg/L which would be in I or II grade according to water quality criteria by Ministry of Environment but BOD level in Mankyeong downstream ranged from 6.87 to 9.72 mg/L. The plant species of river flora were found 251, 98 and 85, upstream midstream and down stream, respectively. Among the surveyed plants, Ceratophyllum demersum, submerged plant and Nuphar subinteperrimum took up higher contents of phosphate and nitrogen than other piano. The Phragmites communis and Zizania latifolia having much biomass were thought to be suitable plants for enhancement of e natural water purification.

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.600-606
• /
• 2019

The study site was the camping area in the Hwarang Amusement Park in Danwon-gu, Ansan-si. Study activities were conducted three times a week from July 20, 2018, to August 1, 2018. A control site, natural enemy site, and Bti(Bacillus thuringiensis israelensis) site were selected. The analyses included habitat environment and species composition analyses, community analysis, correlation analysis, and similarity analysis. The water quality analysis found no significant difference in water quality over the study period (p>0.05). A total of 4,818 individuals, 38 species, 22 families, and 11 orders were observed during the study period. The natural enemy site observed during the study period had a similar species composition as the control site. The Bti site differed from other sites by the low number of species and individuals present. According to the community analysis, the natural enemy site was a stable community and the Bti site was an unstable community during the study period. Diptera showed negative associations with temperature and water temperature and mosquito larvae showed significant correlations with temperature and water temperature. The similarity analysis showed that the control site and the natural enemy site were 61.11-73.68% and the Bti site showed 30.77-56.00% similarity.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.2
• /
• pp.77-84
• /
• 2012

This study suggested the planting model of Zelkova serrata communities in the areas with the warmth index of both 80~100 and $100{\sim}120^{\circ}C{\cdot}month$. Warmth index was calculated with 449 weather points using inverse distance weighted interpolation method. The planting species were selected by correlation analysis between Z. serrata and each species of four or more frequency among the 36 relev$\acute{e}$ surveyed for this study. The result of this study is summarized as follows : Warmth index of Z. serrata communities was among $74{\sim}118^{\circ}C{\cdot}month$. Results of the correlation analysis between Z. serrata and each species observed that the Z. serrata belongs to the tree layer with warmth index of 80~100 and $100{\sim}120^{\circ}C{\cdot}month$. On the other hand, the species of Carpinus laxiflora, Quercus serrata, Prunus sargentii and Platycarya strobilacea appeared only in the tree layer with warmth index of $80{\sim}100^{\circ}C{\cdot}month$. Z. serrata and Styrax japonica appeared in the subtree layer with the warmth index of 80~100 and $100{\sim}120^{\circ}C{\cdot}month$, while Acer pseudosieboldianum, Lindera erythrocarpa, Acer mono, Quercus serrata, etc. appeared in the subtree layer with the warmth index of $80{\sim}100^{\circ}C{\cdot}month$. Z. serrata, Ligustrum obtusifolium, Lindera obtusiloba, Callicarpa japonica and Zanthoxylum schinifolium all appeared in the shrub layer with the warmth index of 80~100 and $100{\sim}120^{\circ}C{\cdot}month$. Lindera erythrocarpa, Orixa japonica, Staphylea bumalda, Akebia quinata and Sorbus alnifolia appeared in the shrub layer with the warmth index of $80{\sim}100^{\circ}C{\cdot}month$ and Styrax japonica and Stephanandra incisa appeared in the shrub layer with the warmth index of $100{\sim}120^{\circ}C{\cdot}month$, The numbers of each species planted in a $100m^2$ area of the Z. serrata community were suggested as follows : five in tree layer, five in subtree layer and nine in shrub layer. The average area of canopy are suggested to be about $86m^2$ for tree layer, $34m^2$ for subtree layer and $34m^2$ for shrub layer.

• Korean Journal of Plant Resources
• /
• v.23 no.4
• /
• pp.261-273
• /
• 2010

This study intended to investigate the environmental factors including soil and vegetation in order to understand the environmental and ecological characteristics of seven different habitats of Viola websteri. These habitats, according to investigations, are mostly located on the slope of mountains facing north at an altitude of 343 m to 991 m above sea level with angle of inclination from 1 degree to 33 degrees. The type of soil is mostly sandy loam and the average field capacity of soil is 28.97%. Their average organic matter is 16.63%, soil pH 5.62, and available phosphorus is 14.75%. A total of 133 vascular plants are identified in 18 quadrates of seven habitats. Dominant species of woody plants in seven habitats are represented as Acer pictum subsp. mono and Quercus mongolica in tree layer, and Acer pictum subsp. mono in subtree layer. Importance value of Viola websteri is 9.66%, as regards the herbaceous layer, and five highly ranked species such as Meehania urticifolia(8.53%), Pseudostellaria heterophylla(6.51%), Hylomecon vernalis(5.15%), Oxalis obtriangulata (4.52%), and Pseudostellaria davidii(4.15%) are considered to be an affinity with Viola websteri in their habitats. The degree of their average species diversity is 1.32, and that of dominance and evenness are 0.08 and 0.89, respectively. Correlation coefficients analysis based on environmental factors, vegetation and soil analysis shows that the coverage of Viola websteri is correlated with silt and sand ratio, and coverage of tree layers are correlated with species richness and altitude. Cluster analysis based on vegetation structure of each habitats are forms a three groups.

• Korean Journal of Remote Sensing
• /
• v.37 no.5_1
• /
• pp.917-926
• /
• 2021

Lodging rice is one of critical agro-meteorological disasters. In this study, the UAV-based multispectral imageries before and after rice lodging in rice paddy field of Jeollanamdo agricultural research and extension servicesin 2020 was analyzed. The UAV imagery on 14th Aug. includesthe paddy rice without any damage. However, 4th and 19th Sep. showed the area of rice lodging. Multispectral camera of 10 bands from 444 nm to 842 nm was used. At the area of restoration work against lodging rice, the reflectance from 531 nm to 842 nm were decreased in comparison to un-lodging rice. At the area of lodging rice, the reflectance of around 668 nm had small increases. Further, the blue and NIR (Near-Infrared) wavelength had larger. However, according to the types of lodging, the change of reflectance was different. The NDVI (Normalized Difference Vegetation Index) and NDRE (Normalized Difference Red Edge) shows dome sensitivities to lodging rice, but they were different to types of lodging. These results will be useful to make algorithm to detect the area of lodging rice using a UAV.