Результаты разработки полуэмпирической теории фракционирования концентраций минерального фосфора и азота фитопланктоном в воде фотического слоя по данным мониторинга Севастопольской бухты

Abstract

The article is devoted to the development of the theoretical basis of Academician V.I. Vernadsky's concept of the unity of the processes of reproduction of living matter and its habitat conditions, taking into account the patterns of conditioning the marine environment as a result of primary production processes. The objectives of the study were: to study the distribution of mineral compounds nitrogen (NO₂, NO₃, NH₄) and phosphorus (PO₄) in the waters of the coastal waters of Sevastopol Bay based on the monitoring results of 2012-2014; to develop a semi-empirical mathematical model of the dynamic characteristics of phytoplankton mineral metabolism as a theoretical basis for assessing the impact of meteorological, thermohaline and primary production processes on the biotic conditioning of marine to obtain evidence of the existence of a natural biogeochemical mechanism for regulating the ratio of biogenic elements in water by comparing the results of observations and numerical experiments on the model; to determine the bifurcation role of switching limiting factors in the water of the photic layer and their effect on new primary phytoplankton production and energy dissipation. The work was carried out in the area with coordinates (44^o36.930'N; 33^o30.177'E); the hydrochemical parameters of the samples were determined in a certified laboratory; the primary objectives of the study were: to study the distribution of mineral compounds of nitrogen (NO₂, NO₃, NH₄) and phosphorus (PO₄) in the waters of the coastal waters of Sevastopol Bay based on the monitoring results of 2012-2014; to develop a semi-empirical mathematical model of the dynamic characteristics of phytoplankton mineral metabolism as a theoretical basis for assessing the influence of meteorological, thermohaline and primary production processes on the biotic conditioning of the marine environment; comparing the results of observations and numerical experiments on the model to obtain evidence of the existence of a natural biogeochemical mechanism for regulating the ratio of biogenic elements in water; to determine the bifurcation role of switching limiting factors in the water of the photic layer and their effect on new primary phytoplankton production and on energy dissipation. It was found that on the annual time scale, the primary production of phytoplankton depended on the water temperature and the length of daylight hours, with phosphorus limitation prevailing. From the second half of the growing seasons, there was a tendency for the ratio of concentrations of mineral forms of nitrogen and phosphorus to reach a stationary stoichiometric value of the Redfield parameter Rat = 16. The dependence of the limitation of production processes on the concentration of biogenic elements in the water was reliably described by power functions. The differential semi-empirical model had sufficient objective complexity to be used as a theoretical basis for describing the patterns of biogenic element fractionation by phytoplankton. In numerical experiments on the model, the rule of natural regulation of the productive characteristics of phytoplankton communities was confirmed: "Whenever the concentration of biogenic elements in the aquatic environment deviates from the standard or regionally specific stoichiometric ratio, the functioning of natural photosynthetic systems is always directed towards their restoration." It was established that the primary production of phytoplankton had an impact on the ratio of biogenic elements in the water due to its concentrating function for mineral forms of nitrogen and phosphorus. It has been shown that at the system level, the phytoplankton production system is negative feedback according to Le Chatelier-Brown, which, within certain limits, accelerates the dissipation of energy flows in the biosphere. It was found that on an annual time scale, the primary production of phytoplankton depended on water temperature and daylight duration, with phosphorus limitation prevailing. From the second half of the growing seasons, there was a tendency for the ratio of concentrations of mineral forms of nitrogen and phosphorus to change towards achieving a stationary stoichiometric value of the Redfield parameter Rat = 16. The dependence of changes in the limiting factors of production processes on the concentration of biogenic elements in the water was reliably described by power functions. The differential semi-empirical model had sufficient complexity to be used as a theoretical basis for describing the patterns of fractionation of biogenic elements by phytoplankton. 

Keywords: Sevastopol Bay, biogenic elements, primary phytoplankton production, stoichiometric ratios, theory of mineral metabolism, patterns of biotic conditioning of the marine environment