• Ocean and Polar Research
• /
• v.35 no.3
• /
• pp.219-228
• /
• 2013

In Korea, more than 300 oil spill accidents occur every year. Despite the frequency, only a small pool of data is available on the initial effect of oil spill on macrobenthic fauna inhabiting rocky shores. The aim of this study was to analyze the variation of macrobenthic fauna composition and community structure on rocky shores, and understand the impact of oil on rocky shore organisms after the Hebei Spirit oil spill. Field surveys were carried out in five regions dose to the wreck site in January, April and September 2008. Polluted sites after the Hebei Spirit oil spill showed that biological index consistently decreased for 9 months limited to breeding and recruitment of organisms by spilled oil. Macrobenthic community was subdivided into 3 groups by species elimination and differences between density of major dominant species: enriched biota community under a relatively stable environment, the second with relatively low ecological index and the last with poor community. In this study, species number did not clearly reflect the effect of oil on the rare and mobile species. However, mean density, biomass and community structure showed the effect of oil by considering breeding activity, decline in recruitment and variation pattern with time.

• Journal of Forest and Environmental Science
• /
• v.28 no.4
• /
• pp.232-241
• /
• 2012

We investigated the relationship between vegetation type and soil carbon dynamics in even-aged alder (Alnus hirsuta) and Korean pine (Pinus koraiensis) plantations in central Korea. Both forests were located on the same soil parent material and occupied similar topographic positions. Soil $CO_2$ efflux in the two plantations was determined using a dynamic chamber method accompanied by measurements of soil moisture content and temperature. Mean soil temperature was similar in the two plantations, but mean soil water content was significantly higher in the alder plantation than in the pine plantation. In both plantations, seasonal patterns in soil $CO_2$ efflux exhibited pronounced variation that corresponded to soil temperature. Soil water content did not affect the seasonal variation in soil $CO_2$ efflux. However, in summer, when soil temperature was above $17^{\circ}C$, soil $CO_2$ efflux increased linearly with soil water content in the alder plantation. Estimated $Q_{10}$ was 3.3 for the alder plantation and 2.7 for the pine plantation. Mean soil respiration during the measurement period in the alder plantation was 0.43 g $CO_2\;m^{-2}\;h^{-1}$, which was 1.3 times higher than in the pine plantation (0.33 g $CO_2\;m^{-2}\;h^{-1}$). Higher soil $CO_2$ efflux in the alder plantation might be related to nitrogen availability, particularly the concentration of $NO_3{^-}$, which was measured using the ion-exchange resin bag method.

• Journal of Ecology and Environment
• /
• v.42 no.3
• /
• pp.111-119
• /
• 2018

Background: Juniperus chinensis L. populations are distributed locally on several areas including coastal cliffs which are difficult to access in the central eastern Korea. Wild populations inhabit relatively barren environments such as rocky areas and cliffs, which are very sensitive to even minor environmental disturbances including artificial interventions and natural disturbances, and thus demonstrate great fluctuations in the population size and density. This study aims to analyze the genetic diversity, differentiation, and genetic structure of each population in order to provide useful data required to establish a substantial conservation strategy of J. chinensis. Results: The genetic diversity of J. chinensis at the population level (P = 78.7%, h = 0.282, S.I. = 0.420) was somewhat higher compared with those measured in the same genus, Juniperus. The genetic differentiation degree among nine populations established naturally in central eastern Korea was 11.50% and that among sub-populations within the same area was 5.52%. On the other hand, genetic variation of individuals within the populations was 82.93%. But frequency of the main allele was different among loci. In particular, fixation of allele frequency and occurrence of rare allele in the highly isolated population suggest a likelihood that genetic drift would occur in populations of this plant. As the result of analysis on the genetic structure of nine populations, nearby populations and isolated populations tended to form separate clusters from each other as the hypothetical number of clusters (K) increase. Conclusions: This result implies that if the population size of J. chinensis is reduced due to environmental change and artificial and/or natural disturbances in the future, it could affect negatively on the genetic diversity of the plant species. In order to maintain and conserve genetic diversity of J. chinensis, ecological network, which can help genetic exchange among the local populations, should be prepared, and conservation strategies in situ as well as ex situ are also required with continuous monitoring.

• Journal of Plant Biology
• /
• v.38 no.2
• /
• pp.173-180
• /
• 1995

We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.32-32
• /
• 2019

The aim of this study was to provide basic guidelines for conservation and management of endangered plants in the national parks of Korea. Iris dichotoma Pall. (Iridaceae), which is a popular garden plant, is considered a second-class endangered species by Korean government and it is listed as a EN (Endangered) species in Red Data Book of Korea. We analyzed ecological conditions of I. dichotoma habitats based on vegetation properties and soil characteristics. This species which is known to inhabit in grassland adjacent to the ocean of lowlands slope and its population was located at an elevation of 8 m to 11 m. In the study sites, the mean of soil organic matter, total nitrogen and soil pH were 6.16%, 0.234% and 5.39 respectively. Additionally, the genetic variation and structure of three populations were assessed using ISSR (Inter Simple Sequence Repeat) markers. The genetic diversity of I. dichotoma (P = 59.46%, H = 0.206, S = 0.310) at the species level was relatively high. Analysis of molecular variance (AMOVA) showed 82.1% of the total genetic diversity was occurred in within populations and 17.9% variation among populations. Lastly, we developed predicted distribution model based on climate and topographic factors by applying SDMs (Species Distribution Models). Consequently, current status of I. dichotoma habitats is limited with natural factors such as the increase of the coverage rate of the herbs due to ecological succession. Therefore, it is essential to establish in situ and ex situ conservation strategies for protecting natural habitats and to require exploring potential and alternative habitats for reintroduction.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.22 no.2
• /
• pp.104-111
• /
• 1977

This study was carried out in order to know the ecological variation and yield factors under the Korea weater with the 25 sunflower varieties which have been introduced from abroad recently. As the results of this of this study we can conclude that high yield and high oil content varieties seemed to have the short period comparatively from planting to head visible and to have long period from flowering to maturity.

• Korean Journal of Environment and Ecology
• /
• v.28 no.4
• /
• pp.472-483
• /
• 2014

Major cities have strengthened their efforts to improve the environmental function of the urban forest through aspects of quantity and quality. Yet, it is difficult to propose both long-term improvement and management policy direction continuously due to a lack of evaluating method that social needs could be reflected. After all, effective strengthening of the function of an urban forest, composed of social and biotic environments, is essential to create evaluation criteria. Such data reflects a quantity variation and identifies the distribution and habitation of biotic sources as well. An assessment of utilization possibilities presents such values as a green connectivity, an ecological healthiness, and usage and access opportunities. Consequently, this research was executed to create an urban forest sustainability index that proposes a management and policy direction based on the evaluation of quantity and quality aspects. This study was processed by the following steps: a degree of importance of ecological aspect, a sub-classification index choice, and an examination of adequacy. This research was conducted from premises that urban forest had another functions comparisons to a natural forest. As a result, a criteria of sustainability should be considered to evaluate an ecological aspect, as well as the social and management aspects regarding human disturbance. This research is designed to develop an evaluation index for ecological aspect. In order to evaluate the ecological healthiness of an urban forest, a vegetation index considers aspects of related rarity, damage possibility, naturalness, area, and diversity. In a wildbird index-related study, forest duration and area were selected. Finally, a variance analysis is presented, inclusive of stability, naturalness, diversity, potentiality, and possibility of wildlife inhabitation, which is indicative of an urban forest sustainability index.

• Journal of Korean Society of Forest Science
• /
• v.103 no.1
• /
• pp.105-112
• /
• 2014

The main purpose of this study is to measure spatio-temporal variation of forest tree volume based on the RCP(Representative Concentration Pathway) 8.5 scenario, targeting on Pinus densiflora forests which is the main tree species in South Korea. To estimate nationwide scale, $5^{th}$ forest type map and National Forest Inventory data were used. Also, to reflect the impact of change in place and climate on growth of forest trees, growth model reflecting the climate and topography features were applied. The result of the model validation, which compared the result of the model with the forest statistics of different cities and provinces, showed a high suitability. Considering the continuous climate change, volume of Pinus densiflora forest is predicted to increase from $131m^3/ha$ at present to $212.42m^3/ha$ in the year of 2050. If the climate maintains as the present, volume is predicted to increase to $221.92m^3/ha$. With the climate change, it is predicted that most of the region, except for some of the alpine region, will have a decrease in growth rate of Pinus densiflora forest. The growth rate of Pinus densiflora forest will have a greater decline, especially in the coastal area and the southern area. With the result of this study, it will be possible to quantify the effect of climate change on the growth of Pinus densiflora forest according to spatio-temporal is possible. The result of the study can be useful in establishing the forest management practices, considering the adaptation of climate change.

• Journal of Digital Convergence
• /
• v.20 no.4
• /
• pp.469-482
• /
• 2022

The purpose of this study is to analyze regional variation factors of hypertension treatment rate in COVID-19 based on the analysis results based on ecological methodology. To this end, data suitable for ecological analysis were collected from the Korea Centers for Disease Control and Prevention's regional health statistics, local government COVID-19 confirmed cases, National Health Insurance Corporation, Health Insurance Review and Assessment Service's welfare statistics, and Korea Transport Institute's traffic access index. Descriptive statistics and correlation analysis were conducted using SPSS Statistics 23 for regional variation and related factors in hypertension treatment rate, and geographical weighted regression analysis was conducted using Arc GIS for regional variation factors. As a result of the study, the overall explanatory power of the calculated geo-weighted regression model was 27.6%, distributed from 23.1% to 33.4% by region. As factors affecting the treatment rate of hypertension, the higher the rate of basic living security medical benefits, diabetes treatment rate, and health institutions per 100,000 population, the higher the rate of hypertension treatment, the lower the number of COVID-19 confirmed patients, the lower the rate of physical activity, and the alcohol consumption. Percentage of alcohol consumption decreased due to COVID-19 pandemic. It was analyzed that the lower the ratio, the higher the treatment rate for hypertension. Based on these results, the analysis of regional variables in the treatment rate of hypertension in COVID-19 can be expected to be effective in managing the treatment rate of hypertension, and furthermore, it is expected to be used to establish community-centered health promotion policies.

• Korean journal of applied entomology
• /
• v.54 no.2
• /
• pp.137-144
• /
• 2015

Plants can affect adversely the interaction among herbivores by inducing insect resistance chemicals and change of attack behavior of natural enemies. Also, plants may induce favorable effects to herbivores by production of allelochemicals, nutritional variation, or morphological changes. In this review, we examined the effects of the interaction among herbivores mediated by plants and plant-response induced by insect attack, or the life history strategies of insects on the community structure of herbivore insects, and discussed its ecological significance in community level.