The article proposes one of the tools for effective forest management – a methodology for assessing forest biodiversity based on the Shannon index or the evenness of biomes formed by dominant edificator trees. The concept is given and the formula for determining the Shannon biodiversity index for communities (biomes) is provided, depending on the probability distribution of edificator trees. Moreover, the biome index is determined on the basis of the occurrence, and the probability distribution of edificators is determined by the dominant species: larch, pine, cedar, spruce and birch on the territory of their continuous and mosaic growth in the taiga and forest-tundra zones of forestry enterprises in the north of Western Siberia. This makes it possible to give a preliminary estimate of the possible values of the biodiversity index of a vast area occupied by forest using satellite observations. Using the descriptions of biomes of the noted edificator trees given by B.N. Norin, V.I. Valutskiy and E.I. Lapshina, the authors of the article obtained indices of the Shannon biodiversity and uniformity for a number of biomes similar in terms of growing conditions to the forest zone of the Yamalo-Nenets Autonomous Area. The probability distribution of edificator trees was obtained on the basis of data on the growing area of these species on the interactive map “Forests of Russia” as of 01.01.2018. As a result, an assessment of the biodiversity of the forest area in each forestry enterprise was obtained and a map of the Yamalo-Nenets Autonomous Area forestry enterprises with the digital values of this index is provided.