• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.15-29
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• 2021

The purpose of this study is to establish an ecosystem model that can predict ecosystem fluctuations in the Nakdong estuary, and use this model to calculate total primary production and respiration. AQUATOX model was used as the ecosystem model, and the model was calibrated and verified using the measured data. For the calibration of the model, chlorophyll-a data measured at the Nakdong estuary were used, and the model verification was performed using DO, TN, and TP data. In general, the total primary production and respiration volume vary greatly depending on the season, but the total primary production and respiration in the Nakdong estuary were greatly influenced by the amount of water discharged from Nakdong estuary bank. When the amount of effluent increased, photosynthesis could not be performed due to the loss of phytoplankton living in the lower area, and the total primary production amounted to zero, whereas the respiration increased sharply due to the inflow of organic substances contained in the effluent. The increase in the inflow water means the inflow of organic substances contained in the inflow water, and the organic substances are decomposed by oxidation, reducing dissolved oxygen. Compared with other countries' estuaries, the Nakdong estuary shows the lowest total primary production and because the respiration is larger than the total primary production, the dissolved oxygen is depleted by the oxidation of organic matter.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.259-273
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• 2022

Interactions between species in a community are very complex, and they are visualized and analyzed through a food web in simple way. Food web is a network of species connected by trophic links showing energy flow from prey to predator. Various models were developed to characterize the food web in ecosystems. In this study, we classified food web models to static models such as Ecopath and dynamic models such as AQUATOX. We presented characteristics of several different types of food web models in each category, and reviewed their applications used in aquatic ecosystems. Finally, we presented issues to be considered to develop food web models.