The dependence of redfield ratio from phase of water regime of river ecosystems

The authors compared the Redfield ratio (RR) of water in rivers Prut, Dniester and Siret in the Chernivtsi region within a phase of the lower summer and spring floods. Samples of water were taken by Rutner's batometr near two types of flood plains it is meadow and forest flood plains. Statistical analysis was performed by using computer program Statistica 6.0. Compliance of distribution of Redfield ratio determined by cumulative criteria: the convergence median, mean and fashion, zero index of asymmetry and kurtosis, confirm the hypothesis H0 by Shapiro-Wilk criterion. On the basis of nonparametric statistics proved the accuracy of the difference between the distributions by this indicator compared to the aqueous phases. It is shown that ratio of the sum ranks of the Redfield index in the phase of spring floods in the lower summer flows phase for all rivers it is constant and is 2.8. For all rivers of Chernivtsi region discovered a greater magnitude values of the Redfield ratio during the spring flood period in comparison with the lower summer flows too. Based on the Redfield calculator found that during the spring flood the mean and median of the RR of all investigated rivers of Chernivtsi region are in a range favorable for the development of green algae. During the summer low water the average values and median Redfield of water of the rivers Siret and Prut in the range favorable for the development of blue-green algae, and the Dniester River – in the range, which is characterized by minimal development of both groups of algaes. Was established a descending series by to the median of Redfield ratio for study the rivers during the spring flood: Dnister (229,5)  Prut (185,8)  Siret (53.4). Instead, during the lower summer flows the median of Redfield ratio of the Prut and Siret coincide and descending series takes the following form: Dniester (18,4)  Prut = Siret (5.8). Convergence of the mean and median Redfield ratio was fixed for both phases of the water regime of the river Siret, it shows indicating to a smaller contribution of the anthropogenic component in the formation of its significance for the these river compared with the other two rivers.