GROWTH SIGNS OF Nymphaea candida IN VARIOUS ECOLOGICAL AND CENOTIC CONDITIONS OF DESNA BASIN (UKRAINE)

Abstract

Nymphaea candida J. et C. Presl. is a relict species which is a typical representative of an ecological group of attached aquatic higher plants with floating leaves. The conducted research was meant to evaluate the indicators that characterize the Nymphaea candida growth in different conditions of the Desna River basin and to find out the influence of the leading ecological-cenotic factors on them. Based on the analysis of 12 dynamic metric morphological parameters values and five dynamic allometric values, the information on Nymphaea candida plant growth rate in six communities is provided. The influence on the growth of such environmental factors such as the phytocoenoses Total plant cover, water column, its transparency andnature of bottom sediments was evaluated. The water colum and phytocoenoses overall projective coverage showed statistically significant effects, with a force of 54.4-99.0% and 23.6- 90.0%, respectively, on all dynamic morphoparameters of Nymphaea candida plants. The bottom sediments did not show a statistically significant effect on only one morphoparameter, and the factor influence force on the dimensional features of Nymphaea candida plants mainly varies within 8.7-89.5%. Water transparency did not show a statistically significant effect on the three morphological parameters, given the influence of this factor on all other features at the level of 13.2-19.4%. In Nymphaea candida plants, the largest majestic significant proportion (58.8%) of the dynamic morphoparameters were in the population of Nymphaea candida - Potamogeton lucens community, the smallest (in 64.7%) were in Numphoides peltata - Ceratophyllum demersum. The fastest growth of Nymphaea candida plants is in areas where there is no flow, the water columnvaries within 50-100 cm, the water transparency reaches the bottom, the silt bottom sediments are represented, and the phytocoenoses total projective coverage is 60-85%. Nevertheless, the total plant cover of Nymphaea candida can be from 10% to 40%. Within the study area, such habitat conditions are optimal to ensure the continued existence of populations of this species as a whole.