Effect of Illumination on the Reproductive Success of Platanthera Bifolia (L.) Rich. (Orchidaceae) on the Northern Border of the Range (Komi Republic)

The influence of illumination conditions on the reproductive characteristics of the rare orchid Platanthera bifolia (L.) Rich has been studied on the territory of the Komi Republic, where the species is located on the northern border of its range. In 2023, five populations of the species were surveyed in habitats with varying level of canopy closure (from 6.5 to 82.3%). It was found that there is a decrease in the values of some indicators of reproductive success: the number of flowers, the proportion of generative plants, and the main indicators of seed productivity, according to the gradient of increasing of the level of canopy closure.