Preservation of biological diversity: top-priority tasks of society and state

In this article a concept and meaning of the term 'biological diversity" associated with the variety of living organisms is described. A scheme of structural-functional links among the basic levels of organization of the living things taken from the monograph by Prof. M.A. Holubets is represented and discussed. The biodiversity of Ukraine is characterized and the role and significance of the Red Book of Ukraine is critically evaluated. The author describes thoroughly a paradigm, object, subject and research methods of a new biological science, biodiversitology. A proper attention is paid to the studies for threats of impoverishment and extinction of different structures of the biodiversity, as well as the actions required for protecting populations of rare and relict species and landscapes and those valuable for the medicine, industry and science, which are commonly recognized and conserved because of their historical and cultural values. The tasks of Ukrainian botanists, zoologists and hydrobiologists are examined in relation with the International Year of Biodiversity announced by the United Nations in 2009.