ADAPTIVE PECULARITES OF CHLOROPHYLL CONTENT DYNAMICS IN PINUS SYLVESTRIS AND PICEA OBOVATA CONIFERS UNDER VEGETATION CONDITIONS IN THE SOUTH OF EASTERN SIBERIA

Abstract

One of the most important factors in the study of photosynthesis is the state of the pigment Fund of the photosynthetic apparatus. Under different climatic and natural conditions, photosynthetic activity will tend to the maximum values. In the conditions of the South of Eastern Siberia, coniferous stands are most widespread, the stability and biological productivity of which directly depends on the realization of photosynthetic potential during the growing season. The study presents the analysis of the dynamics of the content of photosynthetic apparatus pigments of common pine (Pinus sylvestris L.) and Siberian spruce (Picea obovata Ledeb.) at optimal moisture and unfavorable soil humidity during vegetation season. The material was selected at the experimental site located on the outskirts of Irkutsk (the territory of SIFIBR SB RAS). The content of chlorophyll a and b in needles was determined using the SF 56 spectrophotometer in an extract with acetone during the vegetation periods under study. Photosynthetic uptake of carbon dioxide by needled shoots of the pine and spruce of the second year of lifespan was recorded by a multi-channel unit mounted on the basis of the IK gas analyzer “Infralyt-4”. Two types of coniferous photosynthesis strategies are shown under different humidification conditions. It was found that under different conditions of soil moisture during the growing season in coniferous trees, the dynamics of chlorophyll content in light-harvesting complexes of photosystem II has several periods of increase.

Keywords

• chlorophyll
• light-harvesting complexes
• photosynthetic apparatus
• photosynthesis
• adaptation
• climatic factors
• coniferous trees