Pohorielova M. Macrophytes of different types of wave-dominated delta distributary channels (on the example of the Kilia Danube Delta)

The paper is devoted to macrophytes of the distributary channels of the secondary wave-dominated delta of the Danube Kilia arm. Their species richness has been studied, the systematic, ecological, geographical structure is analyzed and the vegetation structure is established. Peculiarities of macrophytes distribution along the distributary channel depth and length have been revealed. The process of distributary channel overgrowth is studied; its dependence on runoff reduction is established. The regularities of the distribution of species richness and the manifestation of the marginal effect on the final sections of the distributary channels and in the canals connecting the lentic and lotic systems are revealed. Cluster analysis of hydrological parameters of the studied watercourses allowed to identify five groups of watercourses that differ significantly in floristic, vegetation composition and the nature of overgrowth. An assessment of anthropogenic impact was carried out and reference conditions for KDD watercourses were established. It is shown that among the three European indices used to assess the ecological status of surface water bodies. The most suitable is the IBMR index, according to which distributary channels of Kilia delta are in high, good and moderate status.