Climatic Response of Larch (Larix sp.) Radial Increment in Provenances on the Krasnoyarsk Forest Steppe

This article presents the results of a comparative analysis of the radial increment of various larch species and provenances growing on a common ecological background in experimental forestry established in 1965–1967 on the Krasnoyarsk forest steppe by employees of the Sukachev Institute of Forest, Siberian Branch, Russian Academy of Sciences. The provenances of Siberian larch ( Larix sibiric a Ledeb.) from different elevation belts of the Southern Siberian Mountains, Gmelin larch ( L. gmelinii Rupr.) from the Trans-Baikal and Zeya provinces (Eastern Siberia), and Japanese larch ( L. leptolepis Gord) introduced from the island of Sakhalin are studied. Based on the cluster analysis of radial increment series, four groups of provenances are identified with different growth strategies, depending on the response to environmental factors: mountain–forest steppe and mountain–taiga provenances of Siberian larch and provenances of Gmelin larch from Transbaikalia. The provenance of Japanese larch from Sakhalin has formed a separate cluster. The highest values of radial increment are found in groups of mountain–forest-steppe provenances formed by Siberian larch and Gmelin larch trees introduced from East Siberian provinces. Low values of radial increment are noted in provenances of Siberian larch trees from Southern Siberia mountain–taiga zone and Japanese larch from Sakhalin. Dendroclimatic analysis is used to identify the relationship between the environmental variables of the introduction zone and the radial increment of the studied provenances. In the Krasnoyarsk forest steppe, the main factor limiting radial increment is the moisture content of the root layer in the middle of the growing season (July–August). Larch trees introduced from wetter habitats respond more strongly to an increase in water stress, while the radial increment of trees taken from drier habitats responds positively to an increase in the length of the growing season.