Characteristics of the photosynthetic apparatus of Pinus sylvestris L. and Larix sibirica Ledeb. from different locations of the Irkutsk region (Eastern Siberia)

Abstract

Abstract The characteristics of the photosynthetic apparatus of coniferous growing in various forest types and climatic conditions of the Irkutsk region (Taishet, Bratsk, Shelekhov, Irkutsk districts) have been explored. The content of photosynthetic pigments, total, free, and bound water in the needles of P. sylvestris and L. sibirica were studied. Using a pulse fluorimeter PAM 2500 (Waltz, Germany), the chlorophyll fluorescence in needles was measured based on such induction curve indices as Fv/Fm, Y(II), NPQ, and ETR. According to the chlorophyll fluorescence induction curve parameters of Scots pine and Siberian larch needles growing in different forest growth conditions, the most effective potential of primary photochemical processes in PSII was observed in Scots pine. While studying the pigment fund of Scots pine and Siberian larch needles, it was found that the highest values of the content of chlorophyll (Chl) a, b, and carotenoids were observed in P. sylvestris and L. sibirica growing in the climatic and forest growth conditions of the Shelekhov district. It is assumed that the revealed characteristics of the parameters reflect the processes of adaptation of the photosynthetic apparatus to various environmental conditions during vegetation development, as well as its high plasticity in different climatic growth conditions.