The ecosystem provides a diverse array of environmental conditions for organisms, and only those that are capable of successfully adapting to these conditions within their habitats can endure, thrive, and proliferate. Further, the environmental conditions within these habitats can significantly affect the bioavailability of chemicals that are introduced therein, thus resulting in varied adverse impacts on the organisms. The present study aims to evaluate the sensitivity of Yuukianura szeptyckii - a species adapted to riparian - to heavy metals following ISO guideline 11276, with the objective of assessing its potential as an indicator species for ecotoxicological evaluations in riparian habitats. The findings revealed that cadmium and copper both had significant toxic effects depending on their concentrations. For cadmium, the LC50 was 280 mg kg-1, EC50 was 66 mg kg-1, and NOEC and LOEC were 25 and 50 mg kg-1, respectively. For copper, the LC50 was 911 mg kg-1, EC50 was 151 mg kg-1, and LOEC was 50 mg kg-1. Comparative analysis with previous results for the international standard species Folsomia candida and the domestic standard species Allonychiurus kimi indicated that Y. szeptyckii exhibited even greater sensitivity to toxicity values. The adverse effects on survival and reproduction were closely associated with the influx concentration of heavy metals in their bodies. Altogether, the results suggest that Y. szeptyckii is a sensitive species for ecotoxicological assessments in riparian habitats, thus making it suitable as an indicator species, particularly in riparian ecosystems that are characterized by relatively high humidity conditions.

Many changes in the scale and structure of the Korean rice cropping system have been made over the past few decades. Still, insufficient research has been conducted on the sustainability of this system. This study analyzed changes in the Korean rice cropping system’s sustainability from a system ecology perspective using an emergy approach. For this purpose, an emergy table was created for the Korean rice cropping system in 2011, 2016, and 202, and an emergy-based indicator analysis was performed. The emergy analysis showed that the total emergy input to the rice cropping system decreased from 10,744E+18 sej year-1 to 8,342E+18 sej year-1 due to decreases in paddy field areas from 2011 to 2021, and the proportion of renewable resources decreased by 1.4%. The emergy input per area (ha) was found to have decreased from 13.13E+15 sej ha-1 year-1 in 2011 to 11.89E+15 sej ha-1 year-1 in 2021, and the leading cause was a decrease in nitrogen fertilizer usage and working hours. The amount of emergy used to grow 1 g of rice stayed the same between 2016 and 2021 (specific emergy: 13.3E+09 sej g-1), but the sustainability of the rice cropping system (emergy sustainability index, ESI) continued to decrease (2011: 0.107, 2016: 0.088, and 2021: 0.086). This study provides quantitative information on the emergy input structure and characteristics of Korean rice cropping systems. The results of this study can be used as a valuable reference in establishing measures to improve the ecological sustainability of the Korean rice cropping system.

Glyphosate, a worldwide most used herbicides, can have complex implications for terrestrial ecosystems, extending beyond its intended target, weed control. This study investigated the cascading effects of glyphosate application on both plant and collembolan communities. Our findings reveal that glyphosate application can reduce the richness of plant communities, and these effects can be pronounced in areas with low initial plant diversity. Furthermore, our results confirm that the fluctuations in plant community composition induced by glyphosate application can also impact the richness of collembolan communities. This research highlights the importance of considering both plant and invertebrate communities when assessing the impacts of herbicide use in agroecosystems.

The effects of temperature and salinity on egg development and settlement of the ascidian Herdmania momus were investigated. Adult specimens were collected from the Dodu Yacht facility in Jeju Island, Korea (33°30′30.54″N, 126°27′55.46″E) in August 2018. Egg development and larval settlement were observed and recorded at 8 h intervals using a stereomicroscope, under nine temperature (10, 13, 16, 19, 22, 25, 28, 31, and 34°C), and four salinity regimens (28, 30, 32, and 34 psu). The highest hatching rate (82.8±7%) was observed at 32 psu and 25°C and the lowest hatching rate (1.0±2%) was at 34 psu and 13°C. The developmental rate (0.222±0.0994) was highest at 28 psu and 28°C, and lowest (0.016±0.008) at 30 psu and 13°C. The highest settlement success rate (77.1±5%) was at 32 psu and 25°C and the lowest (0.1±1.0%) was at 30 psu, and 13°C. The rate of settlement (0.080±0.000) was highest at 28 psu and 28°C, and lowest (0.013±0.000) at 30 psu and 13°C. Both hatching and settlement success rates increased as temperature increased and tended to decrease beyond an optimal temperature range. Herdmania momus preferred 30-34 psu salinity and 22-25°C temperature. This study provides baseline information about the life history of H. momus, and important data to control the damage caused by the increase in number and distribution of this invasive ascidian.

본 연구의 목적은 질산, 황산, 암모니아수, 과산화수소에 대한 생태독성평가를 통해서 사고대비물질들에 대한 기초 독성 데이터베이스를 구축하여, 향후 화학사고 발생시 환경 피해에 관한 의사결정에 과학적 근거를 제공하는 데 있다. 이를 위해 본 연구에서는 사고대비물질 중 토양의 물리·화학적 성질을 변화시킬 수 있는 질산, 황산, 암모니아수, 과산화수소를 대상으로 국내 토착 절지동물인 김어리 톡토기 (Paronychiurus kimi)를 이용한 생태독성평가를 수행하였다. 7일간의 급성독성평가와 28일간의 만성독성평가를 수행하였으며, 시험물질 농도에 따른 토양의 pH 변화를 관찰하였다. 토양의 pH는 질산, 황산, 과산화수소, 암모니아수의 농도가 10,000 mg kg-1 soil dry wt.일 때, 각각 2.86, 2.72, 7.18, 9.69이었다. 질산, 황산, 과산화수소, 암모니아수에 대한 만성독성평가 결과, LC50 값은 각각 2,703, 5,414, 3,158, 859 mg kg-1 soil dry wt.이었으며, P. kimi의 산란 수에 대한 EC50 값은 각각 587, 2,148, 1,300, 216 mg kg-1 soil dry wt.이었다. 비록 본 연구에서는 사고대비물질들의 유입에 따른 토양 pH의 변화만이 조사되었지만, 본 연구의 결과는 P. kimi가 사고대비물질에 의해 변화된 토양의 pH뿐만 아니라 사고대비물질의 유입에 의해 감소된 유기물 함량과 생성된 반응 산물에 의해서도 사망률과 산란수에 영향을 받을 수 있음을 의미한다. 대부분의 사고대비물질들이 토양의 특성을 변화시킬 수 있다는 점을 감안할 때, 토양의 특성 변화와 이에 따른 생물 영향을 고려한 화학사고 후 평가 및 복원 방법이 필요하다.

The purpose of this study was to investigate the toxic effects of zinc in collembolan Paronychiurus kimi at the individual (survival and juvenile production) and population (population growth and age structure) levels after 28 days of exposure in artificially spiked soil. These toxic effects were interpreted in conjunction with the internal zinc concentrations in P. kimi. The EC50 value for juvenile production based on the total zinc concentration was 457 mg Zn kg-1 dry soil, while the LC50 value for adult survival and ri=0 value for population growth were within the same order of magnitude (2,623 and 1,637 mg Zn kg-1 dry soil, respectively). Significant differences in adult survival, juvenile production, and population growth compared with the control group were found at concentrations of 1,500, 375, and 375 mg Zn kg-1 dry or higher, respectively, whereas significant differences in the age structure, determined by the proportion of each age group in the population, were observed in all treatment groups. It appeared that the internal zinc level in P. kimi was regulated to some extent at soil zinc concentrations of ≤375 mg Zn kg-1 dry soil, but not at high soil zinc concentrations. These results indicate that, despite zinc being regulated by P. kimi, excess zinc exceeding the regulatory capacity of P. kimi can trigger changes in the responses at the individual and population levels. Given that population dynamics are affected not only by individual level but also by population level endpoints, it is concluded that the toxic effects of pollutants should be assessed at various levels.

During a recent study to understand an interaction of Collembola community and their environmental factors, two species in the genus Folsomia, F. quadrioculata Tullberg 1871 and F. octoculata Handschin 1925, were found in the forest of South Korea. From 2013 to 2015, these two species were sampled from six mountains and F. quadrioculata or F. octoculata was the dominant species in 5 sampling sites among 6 sampling sites. F. quadriocualta and F. octoculata were found in litter of deciduous and pine forest, respectively. Therefore, the major tree species seems to be one of the important factors determining their habitat. F. quadiroculata is newly recorded from the Korean Peninsula and F. octoculata is redescribed based on new materials from South Korea.

In this study, Folsomia octoculata and Folsomia quadrioculata which is common and representative Collembola species in temperate forests of Korea, were selected as potential bioindicator species. Through three years of survey of the density of the two Folsomia species and environmental factors of the sampling sites, the distribution and habitat preference of the two Folsomia species was investigated. The habitats of the two species were highly distinguished, mainly due to differences in preference for temperature, organic matter content, pH, available phosphorus. In addition, these two-species showed different preferences for vegetation. F. quadrioculata and F. octoculata were mainly found in habitat which Quercus and Pinus sp. live, respectively. This is because the distributions of two tree species are the result of interaction with temperature, available phosphoric acid, and soil organic matter content.

Acute and chronic toxicities of methyl ethyl ketone and methanol were investigated on Paronychiurus kimi (Collembola), for evaluating the potential effects of accidental exposures of these chemical substances on the terrestrial environments. This study was undertaken to establish a toxicity database for these chemical substances, which was required for the preparation of the response compensation and liability act for agricultural production and environmental damage. The 7-d acute toxicity and 28-d chronic toxicity were conducted using the OECD artificial soil spiked with varying, serially diluted concentrations of methyl ethyl ketone and methanol. Mortality was recorded after 7-d and 28-d of exposures, and the number of juveniles were determined after 28-d of exposure in the chronic toxicity test. In both assessments, methanol was more toxic than methyl ethyl ketone in terms of mortality (LC50) and reproduction (EC50). The 7-d LC50 of methyl ethyl ketone and methanol were 762 and 2378 mg kg-1 soil dry wt., respectively, and the 28-d LC50s were 6063 and 1857 mg kg-1 soil dry wt., respectively. The 28-d EC50 of methyl ethyl ketone and methanol were 265 and 602 mg kg-1 soil dry wt., respectively. Comparison of results obtained in this study with literature data revealed that P. kimi was more sensitive to methanol than other soil invertebrates. However, given the high volatility of the chemicals tested in this study, further studies are necessary to improve the current test guideline, or to develop new test guidelines for an accurate assessment of chemicals that require toxicity databases for chemical accidents.

To assess the temperature change effects on Collembola communities, we selected 9 Korean mountains in different latitudes. Top soil was collected and Collembola extracted from 3 sites in different elevation in each mountain. Extracted Collembola were sorted to genera and this data were summarized as total abundance, family richness and diversity. Additionally, soil temperature in each plot, physical and chemical properties of the soil was investigated and that correlated with Collembola community data. Average soil temperature and soil properties affected patterns in Collembola abundance and family richness. The results indicate that temperature change and soil properties strongly affected Collembola communities. Therefore, Climate change has high potential to affect Collembola communities.

Estimating compensation payment for environmental damages by chemical accidents has been controversial because accurate quantification of damages of chemical accident is so complicated and there is lack of scientific studies about impact of chemical accidents. In this study, for supporting chemical accidents compensation criteria, the 7 days acute and 28 days chronic toxicity test was conducted with 4 major chemical accident substances (Sulfuric acid, Nitric acid, Methanol and Methylethylketone) according to the OECD 232 guidelines. Methylethylketone was most toxic chemical followed by methanol, nitric acid and surfuric acid. Further study of comparison between pH and chemical effects was needed.

Toxicity test of contaminate soil is very complex because of differential bioavailability in the soil. Therefore, bioavailability of metals in soil is a major factor influencing estimates of toxicity. In this study, the two major test was conducted. First, the toxicity of arsenic for the Collembola, Paronychiurus kimi, was assessed by determining the effects of increasing arsenic concentration on survival, reproduction and body concentration of As in five forested soils with different available phosphate and oxide-metal concentration. Second, the sequential extraction procedure (SEP) for arsenic by choosing extraction reagents commonly used for sequential extraction of metals was tested. The EC50 based on total As concentration in soil was estimated respectively. The available phosphate and oxide-metal concentration in soil influenced on As fraction in soil. Especially, As in soil which is non specifically and specifically sorbed (fraction 1, 2) has strong correlation with available phosphate and oxide-metal concentration (p<0.05). The toxicity is more higher in the soil with high available phosphate and low oxide-metal concentration. In addition, the high arsenic concentration in fraction which is amorphous and poor-crystalline hydrous oxide of Fe and Al (fraction 3) had effect to the toxicity. As a result, the toxicity of As is related with As concentration in fraction 1, 2 and 3 and the soil properties and the arsenic fractionation in soil have a influence on the bioavailability and toxicity.