Structure, pigment content, and photosynthesis of Siberian larch needles in Northern and Sub-Arctic Urals

摘要

The structure and functional organization of the photosynthetic apparatus of Siberian larch growing on the western slope of Northern and Sub-Arctic Urals were studied. The needle morphostructure, the mesophyll cell ultrastructure, and the pigment complex of chloroplasts were quantitatively characterized. Active photosynthesis of larch was observed during warm days with a low deficit of humidity. Photoassimilation depression under hot and dry weather was followed by a decrease in the stomatal conductance of needles. Under extreme conditions of mountains, Siberian larch has low photosynthesis. It decreased gradually from Nothern to Sub-Arctic Urals.