Monitoring of a <i>Cypripedium guttatum</i> (Orchidaceae, Liliopsida) population on the northern border of its distribution range (Komi Republic, European Russia)

Abstract

The results of our 12-year study of a population of the rare orchid Cypripedium guttatum Sw. on the northern border of its range, on the territory of the Komi Republic (north-east of European Russia) are presented. Our research has shown that weather factors (temperature and precipitation) have an impact on the seasonal development of shoots and plant size. The number of shoots is influenced by the weather conditions of the previous growing season, namely: the temperature of the first decade of August influences positively while early autumn frosts and the amount of precipitation of the entire period do negatively. A negative correlation was found between the number of flowering shoots and the temperature of the second decade of July of the previous growing season and a positive relationship between the number of juvenile plants and the precipitation of August of the previous growing season. Fruit set was quite low (17.1%), which is typical for this species. The pollination efficiency of C. guttatum was negatively affected by the high temperature during its flowering (the second decade of June). One box contained an average of 4065 seeds. The real seed productivity per shoot varied from 1989 to 7064 pcs., it is associated with precipitation in the second decade of July of the current growing season. The high number of the population studied (25 thousand shoots), the correspondence of the ontogenetic spectrum to the basic one of the species, the annual presence of juvenile plants of seed origin indicates its stable condition.