Effect of environmental factors on growth and physiological status of generative shoots of Cladium mariscus in a protected calcareous fen habitat

Abstract

Effective conservation of priority habitat 7210* Calcareous fens with Cladium mariscus and species of the Caricion davallianae depends on complete knowledge of the biology of Cladium mariscus. This study was aimed to determine effect of temperature and habitat water level on growth, development and physiological status of generative shoots of C. mariscus. Maximum quantum yield of photosystem II photochemistry dynamics during both seasons was similar; but in summer 2016 the values were significantly higher than in 2015. Difference in height of generative shoots was not found between years. Average number of generative shoots indicated a significant difference between years. Immediate effect of temperature or habitat water level changes on generative shoot growth were not observed. However, two-season measurements of maximum quantum yield of photosystem II photochemistry showed that C. mariscus is welladapted to high habitat water level and might be sensitive to habitat water level fluctuations, when the water level falls below 5 cm. On the north-eastern limit of the distribution range the number of generative shoots of C. mariscus in the next growing season is affected by previous autumn drought and temperature below 0 °C as well.