동해 울릉분지의 동계수직혼합 변동에 따른 식물플랑크톤 기능성 타잎의 변동성: 모델링 연구

Abstract

We investigated the impacts of varying winter vertical mixing and atmospheric deposition on the lower trophic level ecosystem using a zero-dimensional European Regional Seas Ecosystem Model (ERSEM) for 2001-2012. The model results show that the changes in winter vertical mixing had varying effects on the competitive advantages of PFTs and thereby altered the succession process of PFTs in the upper mixed layer. As the winter vertical mixing increases, the annual mean of NPP and peak biomass of the total phytoplankton increased, and vice versa. Diatoms responded most positively to the change. Deepening winter vertical mixing would increase NPP but decrease the biomass of flagellates and picophytoplankton becauseof increased grazing. When winter vertical mixing deepened, the NPP and biomass of dinoflagellates decreased as their growing duration decreased. Because the PFTs showed opposite trends in biomass change, there was no significant increase in the total phytoplankton biomass. Taken together, the model suggests that the shallower MLD in the Ulleung Basin may result in a shift toward dominance of small phytoplankton such as flagellates and picophytoplankton and the increasing atmospheric deposition would amplify such changes. the changes in winter vertical mixing had varying effects on the competitive advantages of PFTs and thereby altered the succession process of PFTs in the upper mixed layer. As the winter vertical mixing increases, the annual mean of NPP and peak biomass of the total phytoplankton increased, and vice versa. Diatoms responded most positively to the change. Deepening winter vertical mixing would increase NPP but decrease the biomass of flagellates and picophytoplankton becauseof increased grazing. When winter vertical mixing deepened, the NPP and biomass of dinoflagellates decreased as their growing duration decreased. Because the PFTs showed opposite trends in biomass change, there was no significant increase in the total phytoplankton biomass. Taken together, the model suggests that the shallower MLD in the Ulleung Basin may result in a shift toward dominance of small phytoplankton such as flagellates and picophytoplankton and the increasing atmospheric deposition would amplify such changes.