Much of the data used in the analysis of environmental ecological data is being obtained over time. If the number of time points is small, the data will not be given enough information, so repeated measurements or multiple survey points data should be used to perform a comprehensive analysis. The method used for that case is longitudinal data analysis or mixed model analysis. However, if the amount of information is sufficient due to the large number of time points, repetitive data are not needed and these data are analyzed using time series analysis technique. In particular, with a large number of data points in the current situation, when we want to predict how each variable affects each other, or what trends will be expected in the future, we should analyze the data using time series analysis techniques. In this study, we introduce univariate time series analysis, intervention time series model, transfer function model, and multivariate time series model and review research papers studied in Korea. We also introduce an error correction model, which can be used to analyze environmental ecological data.

We developed a new ecotoxicological test method using native test species, eggs of Ephemera orientalis, and five kinds of industrial wastewater were tested to validate the test method. The water samples were collected in Jun 2006 from the following industries: pesticide, metal plating, PCB, leather1, and leather2. Wastewater and effluent were diluted by distilled water, respectively, to prepare various concentrations, 100, 50, 25, 12.5, 6.3, 3.1, and 0%. For the egg bioassay, 20 freshly laid eggs (<24 h old) were exposed to test solutions in a Petri dish (52×12 mm) at 20℃ with photoperiod of 16 h light and 8 h dark for 14 days. The median egg hatching concentrations (EHC50) were estimated using Probit analysis. All EHC50s of wastewater were less than 3.1%, which meant very high ecotoxicity except for the wastewater of PCB industry having 6.1% of EHC50. Among the effluents, the least toxic effluent was from pesticide industry having 58% of EHC50, while the effluent of leather2 was the most toxic having 7.3% of EHC50.

Population dynamics of maize weevil, Sitophilus zeamais, and their parasitoids Anisopteromalus calandrae were examined while considering the spatio-temporal interactions using population modelling as a tool. The modelling of two species host-parasitoid systems identified the some factors concerning the long-term dynamics of interacting populations. In the single host system, the total density of S. zeamais increased exponentially and reached a saturated, asymptotic level with time. This stabilization in the density could be explained by the spatio-temporal dynamics among the patches. S. zeamais disperses continuously from patches of high density to those of low density. This density-dependent dispersal could be one of the mechanisms for stabilizing the S. zeamais population density. In the S. zeamais-A. calandrae system, both populations showed long-term coexistence. The long term coexistence could be attributed to spatio-temporal interactions of S. zeamais and A. calandrae resulted from dispersal of host and a non-random searching behavior of the parasitoid. Because such spatio-temporal variation in population dynamics, the overall host-parasitoid system may have been in a stable state, although the local population system in each patch was unstable.

Population dynamics of American serpentine leafminer, Liriomyza trifolii, were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator. The DYMEX model simulator consisted of series of modules with the parameters of temperature dependent development and oviposition model of L. trifolii from pre-published data. Leaf surface temperature of cherry tomato leafs was monitored according to three tomato plant positions using an infrared temperature gun. Air temperature was monitored at same three positions using a self-contained temperature logger. Data sets of observed air temperature and average leaf surface temperatures were prepared, and incorporated into DYMEX simulator to compare the effects of air and leaf surface temperature on population dynamics of L. trifolii. The number of L. trifolii larvae was counted by visual inspection in tomato plants to verify the performance of DYMEX simulation. The egg, pupa, and adult stage of L. trifolii were not counted due to its availability of visual inspection. Based on correlation analysis, L. trifolii was affected greatly by the leaf temperatures, rather than air temperatures.

Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum, were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator. The population phenology model of T. vaporariorum was developed and simulated. Leaf temperature on reversed side of cherry tomato leafs was monitored according to three tomato plant positions (top, >1.6m above the ground level; middle, 0.9 - 1.2m; bottom, 0.3 - 0.5m) using an infrared temperature gun. Air temperature was monitored at same three positions using a temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures. The number of T. vaporariorum immatures was counted by visual inspection in three positions to verify the performance of DYMEX simulation. A significant positive correlation between the observed and the predicted numbers of immature and adults was found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with air temperatures. This study demonstrated that the population dynamics of T. vaporariorum was affected greatly by the leaf temperatures, rather than air temperatures in cherry tomato greenhouses. This work was supported by Development of field-oriented model for forecasting outbreak of diseases or insect pests based on GIS and IT Program (R1003852) from Rural Development Administration, Republic of Korea.

two different sizes of yellow sticky traps (small trap: 9.6×8.0cm; large trap: 9.6×16cm) for sampling greenhouse whitefly (GHWF), Trialeurodes vaporariorum (Westwood), adults in four commercial cherry tomato greenhouses. The patch size of GHWF immatures between plants was also estimated using visual counts. Two variogram models were fitted to the empirical variograms developed from the data collected by each sampling method. All the variograms reached the sill indicating the presence of spatial dependence among the spatial data obtained by the two sampling methods. For GHWF adults on sticky traps the range of variogram (a measure of attractive distance) was not different between the two trap sizes. This result indicated that the attractive distances of the two different yellow sticky traps were very similar. The ranges of the variograms for the visual count of immatures on plants were always less than those for adults, indicating that the attractive distance of the traps for GHWF adults extends beyond the patch size for immatures on cherry tomato plants. These data have implications for developing sampling plans for the management of GHWF in tomato greenhouses.