материалы конференции

En

14th MEDCOAST Congress on Coastal and Marine Sciences, Engineering, Management and Conservation, MEDCOAST 2019

2019

Laboratory experiments show that phytoplankton cells can regulate C/N/P ratios in response to changes of external factors. The adaptation mechanism is determined by physiological response traits, which differ for species and are characterized by significant variability. An effective regulatory mechanism provides the observed plasticity of phytoplankton, which allows it to grow even under severe conditions. We investigated this problem using numerical modelling of phytoplankton community growth under varying conditions. In the proposed model, growth was determined by external (temperature, insolation, nutrients supply) and internal factors, such as nitrogen and phosphorus contents in phytoplankton cells. The internal factors are controlled by an equation reflecting balance between the increase in nutrients content by uptake from the environment and costs on growth. Specified growth rate, nutrient uptake rates depend on nitrogen and phosphorus saturation of cells. All physiological traits, such as half-saturation “constants”, maximum uptake rates, minimum and maximum quotas of nutrients in a cell, maximum growth rate were estimated as functions of temperature, insolation, cell volume, and taxon group using neural network technique. With these approximations in our model, we investigated the influences of irradiance, water temperature and nutrients supply on phytoplankton growth, nutrients assimilation and intracellular stoichiometry.

CELLS, CYTOLOGY, INCIDENT SOLAR RADIATION, NITROGEN, PHOSPHORUS, PHYSIOLOGICAL MODELS, PHYSIOLOGY, PHYTOPLANKTON, RATE CONSTANTS, STOICHIOMETRY

2019-12-12 15:49:00