Climate change is a global phenomenon and has major impacts on ecotoxicology. A variety of environmental variables affected by climate change can alter the fate of chemical and responses of organism. Especially, soil temperature is an important factor in ecotoxicology. Increasing temperature results in an increase in the rate of uptake and degradation of toxic compound. Therefore, the research of temperature effect on toxicity is needed to understand the change of toxic effect under climate change. In this regards, the response of Paronychiurus kimi (Collembola) to Geunsami™ (glyphosate-based herbicide) were evaluated at different temperatures (20℃, 25℃) and soil aging time (7, 15 days). Survived adults and hatched juveniles were counted after 28-day exposures in artificial soil spiked with 1, 5, 50, 100, 500 mg/kg of glyphosate in different temperature and soil aging time conditions. In addition, we investigated the fatty acid composition of Paronychiurus kimi. Increasing soil aging time and temperature, EC20 value of P. kimi was increased. Fatty acid composition of P. kimi was similar with that of Folsomia candida mainly composed of 18:1 w9c, 16:0 and 18:0 fatty acids. UI (Unsaturation Index) and the ratio C16/18 of fatty acid composition decreased with increasing temperature. The 18:0 (Stearic acid) fatty acid increased with increasing concentration of glyphosate.

Behavioral reaction can be measured as a sensitive endpoint for sublethal toxicity of copper, and can be used to obtain easily and quickly. Also behavioral endpoints may serve as a more insightful evaluation tool of the ecological effects of toxic chemicals. In this study, four invertebrates in freshwater which are usually used indicate species for water quality were selected as test species (Chironomus riparius, Heterocypris incongruens, Daphnia magna, and, Triops longicaudatus). Each test species was exposed to copper for 6 hours, and total distance, velocity, and, turn angle were measured for 1 hour using video analysis system (Ethovision : Noldus Information Technology) in laboratory condition. Each endpoints reflected effect of copper toxicity appropriately for all test species. These endpoint have possibility that can be used to identify characteristic behavioral responses to a metal toxicity. We viewed this study as a preliminary experiment for future research to investigate the significance of behavioral endpoints to various toxic chemicals.

Environmental risk assessment aims to estimate the impacts of various stressors on populations and communities in the environment. However, most of the exposure tests conducted under the laboratory level. This gap between the controlled condition of the experiments and the complexity of the field situation can lead to irrelevant estimation of stress effects. For this reason, dynamic model approach in ecology that including integrated mechanistic understanding has become important. The dynamic models at the individual level can be used to interpret the individual’s response to stress, extrapolate which response to untested conditions, and predict the impacts on the higher ecological level. The overall objective of this case study was to simulate the chronic toxicity of copper on Daphnia magna using dynamic energy budget theory with the improved toxicity module component. The model system was constructed and evaluated, using the PowersimⓇ software. The toxicity model system was integrated with toxic effects on allocation of reserve, structure, and maturity energy of D. magna into improved toxicity module. The model was calibrated and verified by actual data sets where obtained from a laboratory experiment including growth, maturity and survival measurement of D. magna during copper exposure. The simulation results showed that the response of D. magna under copper exposure was well estimated by model system.

Recently, an integrated approach in insect ecology that including development of biological models and estimation of various effects using a logical model has become important. Through the biological components of ecosystem having complex temporal and spatial patterns, and complicated interactions of biotic and abiotic factors, dynamic models can be useful tools to investigate the whole ecosystems. Pollutants in terrestrial ecosystem can be transferred to insect body through insect’s sucking plant tissue, and effect on their biological properties. Trend of pollutants transfer from soil to plant root can be estimated using free ion activity model (FIAM), and distribution and accumulation in plant parts can be described by dynamic model with water potential, water translocation, and transfer rate. Biological response of plant and insect can be illustrated the dynamics model based on experiment data. The combination of these models show an overall behavior of toxicant and the interaction between plant and insect with time. The objectives of the research are to comprehensively analyze the transfer and effects of pollutant in soil, plant and insect system and to develop the assessment technique for soil ecosystem using dynamic modelling concerning the causal relationship and feedback processes. We are aimed specifically at prediction and assessment of various polluting scenarios of soil ecosystem through data collection from laboratory and field investigation, modelling and evaluation using module software programing.

A new collembolan species (Paranura rosea) which was native to Korea was selected for evaluating the effect of temperature on their biology. Development, and reproduction of P. rosea were investigated at 15, 20, 25 and 30℃ Hatchability of egg was not affected by experimental temperature, and the lower threshold temperature for development of P. rosea was estimated to be 7.53℃. The temperature reduced the juvenile and adult (maturity period). The intrinsic rate of natural increase and finite rate of increase per week at 20℃ which are maximum values showed significant difference with other experimental temperatures. Survival rate, cumulative reproduction and head capsule width was fitted by several models. Especially, the model which fitted for estimating head capsule width was used to determine their life stage. Estimated head capsule width of P. rosea at the initial oviposition varied with temperature from 0.36 ± 0.007 to 0.45 ± 0.007 with maximum at 20℃ and minimum at 30℃, and significant difference was observed at all the experimental temperature (P<0.05). However, estimated head capsule width at the last oviposition showed different statistically result at only 30℃. Molting frequency per week of one P. rosea was increased as the temperature increased. Based on this study, temperature greatly influenced on their life stage and reproduction. Therefore, relationship between temperature and P. rosea is very important for understanding their biology.

We evaluated the effect of water pH (6, 7, 8 and 9) and hardness (40mg/L and 160mg/L as CaCO3) on the growth of H. incongruens. Both water pH and hardness affected the growth parameter of H. incongruens such as head capsule width and maturity time. The head capsule width of the adults in the highest ph condition was 9.7% increased compared to the lowest ph condition. The maximum difference of the maturity time was 192 hours among the test conditions. Overall, as water ph level increase makes head capsule size of the test animal large, the inter-molt period and maturity time become shorter significantly. The effect of water hardness increasing showed a similar tendency with ph level. Especially, the difference of the growth parameter among the test conditions was increased by growing test animal. There are strong correlation between available amount of intake calcium and growth parameters of test animal. These results indicate that because of calcium demand for growth, water pH level and hardness are the important effect factor in life-cycle of the H. incongruens..

In this study, the toxic effects of fenoxycarb on biological traits of nontarger arthropod P. rosea, Collembola. The tests were assessed in the OECD artificial soil under two different exposure condtions, one was exposed in the bulk soil, and the other was exposed in the compacted soil which unidirectional force was applied to the soil surface. In the bulk system, survived adults and hatched juveniles were counted after 28-day exposures, and in the compact system, survived adults, eggs, hatched juveniles and molts were counted everyday until no more hatching. The toxic effect of fenoxycarb on survival and juvenile production of P. rosea in the bulk system was more toxic than that of the compact system. Juveniles and eggs were seriously affected as compared with toxic effect for adults. Particularly, toxic effect on hatching rate (3.75 mg/kg EC50juvenile) were very higher than that on oviposition (200.868 mg/kg EC50egg) or survival rate of adults ( >1200 mg/kg LC50). The molting freauency of P. rosea was decreased in a concentration dependent manner. These results suggest that the IGRs fenoxycarb exhibit significant impacts on the biological traits of non-target organisms P. rosea and its toxic effects are differently assessed depending on the exposure conditions.

Proteomics may help to detect subtle pollution-related changes, such as responses to mixture pollution at low concentrations, where clear signs of toxicity are absent. Also proteomics provide potential in the discovery of new sensitive biomarkers for environmental pollution. We utilized SELDI-TOF MS (surface enhanced laser desorption. / ionization time-of-flight mass spectrometry) to analyze the proteomic profile of Heterocypris incongruens exposed to several heavy metals (lead, mercury, copper, cadmium and chromium) and pesticides (emamectin benzoate, endosulfan, cypermethrin, mancozeb and paraquat dichloride). Several highly significant biomarkers were selected to make a model of classification analysis. data sets obtained from H. incongruens exposed to pollutants were investigated for differential protein expression by SELDI-TOF MS and decision tree classification. Decision tree model was developed with training set, and then validated with test set from profiling data of H. incongruens. Machine learning techniques provide a promising approach to process the information from mass spectrometry data. Even thought the identification of protein would be ideal, class discrimination does not need it. In the future, this decision tree model would be validated with various levels of pollutants to apply field samples.

The use of insect growth regulators (IGRs) has been gaining popularity as an environmentally friendly option to improve existing integrated pest management (IPM) strategies. Although IGRs have a selective effect on target organisms, they may exert a more selective effect on non-target organisms. In this study, the toxic effects of teflubenzuron on biological traits of P. rosea, Collembola, were assessed in the OECD artificial soil under two different exposure conditions, one was exposed in the bulk soil, and the other was exposed in the compacted soil which unidirectional force was applied to the soil surface. After 28 days of exposure, the toxicity of teflubenzuron on the survival and juvenile production of P. rosea in the bulk system was more toxic than that of the compact system. Moreover, not only the egg production but also the hatching rate and molting frequency of P. roseas was decreased in a concentration dependent manner. These results suggest that the IGRs teflubenzuron exhibit significant impacts on the biological traits of non-target organisms P. rosea and its toxic effects are differently assessed depending on the exposure conditions.

Soil contamination can be one path for stream and groundwater contamination. In this study, the toxicity of soils sampled in the vicinity of the abandoned mine located in the Gyeonggi province was evaluated using freshwater organisms Heterocypris incongruens. Two different exposure scenarios, one is in the aqueous only exposure, and the other is in the aqueous + soil exposure. The seven different soil samples were tested depending on the contamination level; reference (1 soil), moderately contaminated (4 soils) and highly contaminated (2 soils). In the toxicity tests, H. incongruens were exposed to water extracts (aqueous only exposure) and soils (aqueous + soil exposure) which were serially two-fold diluted with either EPA moderate hardwater or clean sand, respectively. After 6 days of exposure, no significant impact on the survival was found in the both systems for reference soil, while only significant impact was found in the aqueous + soil system for moderately contaminated soil. And the survival of H. incongruens was dramatically decreased with decreasing dilution series for highly contaminated soils. Interestingly, the toxicity of aqueous + soil system was higher than that of aqueous only system, implying the exposure of chemicals to H. incongruens may be a consequence of its foraging behavior onto the surface of sediment. From the results of this study, the freshwater organism H. incongruens can be used as surrogate test species to assess the soil contamination.

Sedimentation of soil particles in water is perhaps the most significant pathway to contamination of aquatic ecosystems. In this scenario, the use of freshwater organisms for assessing sediment toxicity will be considered more ecologically relevant than tests that use aqueous soil extracts. To evaluate the toxicity of soils sampled in the vicinity of the abandoned mine located in the Gyeonggi province, Daphnia magna were exposed to a 1:4 of soil to water which soil samples were serially two-fold serially diluted with clean sand to concentrations ranging from 6.25 to 100 % % (w/w) for 24- and 48-h. Irrespective of exposure time, the survival of D. magna for reference soil was not decreased, while the survival of D. magna showed high sensitivity to the soils with moderate as well as high metal concentrations. Moreover, the heavy metal concentrations in the water samples increased with increasing the heavy metal concentrations in the soils, which indicates the increased sensitivity is the consequences of the bioavailable fraction of contaminants in soils. These results clearly showed that the freshwater organism D. magna can be used as test species to assess the potential impact of soil contaminants into aquatic ecosystems.

In recent, the ISO has suggested a new guideline by using an avoidance behavior of soil invertebrates for the use of screening tools in the evaluation of soil contamination. In this study, we used a collembolan, Paronychiurus kimi which is native to Korea, as a test species because of its ecological relevance to Korean soil. The objectives of this study were to evaluate whether the exposure time (24, 48, 72, 96 and 120 h) and cadmium concentration (50, 100, 200 and 400 mg/kg of dry soil) affect the avoidance behavior of P. kimi. Twenty collembolans were introduced to the center of the soil which divided into two sections; cadmium untreated soil was placed in one of the section, and the cadmium treated soil was placed in the opposite section. To minimize soil structural effect on the avoidance behavior, the both soils were compacted by applying unidirectional force to the soil surface. The avoidance behaviors of P. kimi were not significantly affected by cadmium concentrations after 24 and 48 h of exposure, but were significant after 72-120 h. There results showed that avoidance behavior appears to be a good endpoint for the use in evaluation of soil contamination with 72 h of exposure duration.

Male cicadas produced species-specific calling songs to attract conspecific receptive females. Male cicadas typically occupy tree trunks or tree branches during calling song production. We studied calling site preference in four species of cicada: Cryptotympana dubia, Meimuna opalifera, Oncotympana fuscata, and Meimuna mongolica. Several males were observed to sing together in a tree in C. dubia, but males of other species tended to sing singly in trees. There were also cases in which two or three individuals of different species sang together in a tree. Species differed significantly in height of and distance to trunk from calling site. Both tree height and tree crown were significant factors for calling site preference. The height of calling site was the highest in C. dubia, followed by M. opalifera, M. mongolica, and O. fuscata. The distance to trunk from calling site in M. opalifera was the farthest and was significantly different from those of other species. Males of other species tended to sing close to tree trunks. Males of M. opalifera were mobile when they produced calling songs, whereas males of other species were stationary. That is, males of M. opalifera sang only for short periods of time and moved around adjacent trees. Segregation of calling sites suggests that these four cicada species occupy different sections of trees, thereby avoiding competition for calling sites.