Population Structure and Reproductive Success of Cypripedium calceolus (Orchidaceae, Liliopsida) on Karst Landscapes of Southern Timan (Komi Republic): Effect of Slope Exposure

The effect of slope exposure on the population structure, morphometric peculiarities, and reproductive characteristics of the rare orchid Cypripedium calceolus L. in karst landscapes of Southern Timan on the territory of the Paraskinye Lakes Nature Reserve (northeastern European part of Russia) was studied. In 2023, six populations of this species were surveyed on karst landforms: five on slopes of different exposures and one on a flat area. It was detected that the species forms the largest populations on slopes of western and northwestern exposure. In all populations, generative shoots damaged by frosts were noted, but their portion on the western slopes was more than 50%. The slope exposure affects the morphometric indices of shoots and seeds. The fruit set is associated with both weather conditions and exposure: the lowest pollination efficiency was noted on cold northwestern slopes; the highest, on southern ones. A decrease in the real seed productivity of the fruit was detected as the slope orientation changed from north to south (from 9861 to 3761 pieces), which is associated with the underdevelopment of some seeds. The average real seed productivity of the generative shoot on the karst outlets of Southern Timan was 1292 pieces (from 985 to 1769 pieces in different populations). Along with vegetative renewal typical for this species, seed renewal was also noted in the populations studied, which is indicated by the presence of juvenile individuals in them, the portion of which varies from 1 to 13.5%.