Seasonal Changes in the Photosynthetic Pigment Complex of Sphagnum Mosses: The case of Sphagnum papillosum Lindb.

The authors studied the content of photosynthetic pigments and their ratio during the warm period of the year (May–October) and during the period with stable snow cover (April) in sphagnum moss Sphagnum papillosum Lindb. on an oligotrophic bog in Arkhangelsk oblast. The content of photosynthetic pigments decreased from May to July, reaching a minimum, and then increased again by autumn. The content of pigments in moss tissues under the snow was comparable to the July minimum. Based on the results of factor and cluster analyses, it was suggested that the S. papillosum pigment complex in the first half of the growing season is adapted to high insolation and a long photoperiod, which is reflected by such indicators as the chlorophyll a/b ratio and the proportion of chlorophylls in the light-harvesting complex. In addition, during the growing season, the pigment complex apparently adapts to moisture conditions that depend on precipitation, especially during the period of summer decrease in the bog water level, which reflects the Chl/Car ratio.