Seed Productivity of Epipactis atrorubens (Hoffm.) Besser (Orchidaceae, Liliopsida) on the Northern Border of Its Distribution Range

• Published in: Biology bulletin of the Russian Academy of Sciences Vol. 48; no. 10; pp. 1813 - 1821
• Main Authors: Kirillova, I. A., Kirillov, D. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2021; Springer Nature B.V
• Subjects: Anthropogenic factors; Biochemistry; Biomedical and Life Sciences; Cell Biology; Echinacea atrorubens; Ecology; Epipactis atrorubens; Flowers; Fruit set; Geographical distribution; Life Sciences; Limiting factors; Morphometry; Population studies; Productivity; Rare species; Seeds; Shoots; Vegetation; Zoology; reproductive biology; Orchidaceae; fruit set; seed productivity
• ISSN: 1062-3590; 1608-3059
• DOI: 10.1134/S1062359021100137

Orchids, due to their biological features, high decorative properties, and poor resistance to anthropogenic factors, are one of the most vulnerable components in the vegetation of the world. Their conservation cannot be efficient without knowledge of their reproductive biology. These data are especially important for species at the boundaries of their distribution area with additional reproduction-limiting factors. Our object of study is the rare orchid species Epipactis atrorubens (Hoffm.) Besser. During field research on the territory of the Komi Republic (northeast Russia), we studied 50 populations of E. atrorubens . The reproductive characteristics (fruit set, seed productivity, and seed morphometry) were studied in 19 of them. We established that the main limiting factor in the North is the short vegetation period. Frost damages generative shoots and does not allow seeds to ripen. The capsule of E. atrorubens at the northern distribution boundary contains fewer seeds than in the central part of the range. The real seed productivity is also lower here. Within the Komi Republic, in a sample of two sites (the Timan Range and the Ural Mountains), we also noted a decrease in all reproductive characteristics from south to north: the number and size of flowers and the number and quality of seeds decrease, and their shape changes (they become less elongated, which reduces their ability to be distributed). However, the deterioration in seed productivity is compensated for by an increase in the seed volume. Populations of fewer than 50 shoots in which juvenile plants are not found are in critical condition.