The effect of slope exposition on the growth dynamics of Larix gmelinii in permafrost conditions of Central Siberia. I. Differences in tree radial dynamics growth in the north- and south-facing slopes

• Main Authors: А. V. Benkova, D. А. Mashukov, V. Е. Benkova, А. S. Prokushkin, А. V. Shashkin
• Format: Article
• Language: English
• Published: Russian Academy of Sciences, Siberian Branch Publishing House 2015-08-01
• Series: Сибирский лесной журнал
• Subjects: radial increment; climate factors; solar radiation; moss-lichen cover; thermal soil properties; Central Evenkia; Central Siberia
• Online Access: http://xn--80abmehbaibgnewcmzjeef0c.xn--p1ai/upload/iblock/71e/71ed21780948e6d074a0ee1d65f29db4.pdf

This paper is devoted to revealing the distinctive characteristics of radial growth of larch trees (Larix gmelinii (Rupr.) Rupr.) growing in permafrost contrast conditions of the north and south facing slopes (Central Siberia, 64°19´23˝ N, 100°13´28˝ E). Even-aged larch stems regenerated after strong fire in 1899 in opposite north and south facing slopes of the hills situated on the banks of Kulingdakan stream were under study. Two sample sites at the middle part of the slopes were established. 23 model trees in the north facing slope and 13 ones in the south-facing slope were selected for dendrochronological analysis. From each tree, disks at 1.3 m height of the stems were taken. Tree ring widths were measured, comparative analysis of dynamics of radial growth in the slopes was made. In order to separate time intervals, characterized by distinctive climate impact on radial increment, sliding response functions were calculated and analyzed. Daily solar radiation for both sample sites was calculated. The results showed that solar radiation in the north-facing slope is 20 % less than that in south-facing slope. Solar radiation regime promotes intensive thickening of moss-lichen cover, so that its thickness to 2009 was nearly two times thicker than in south-facing slope. Both factors affected the worth thermal soil growth conditions in the north facing slope. The latter was responsible for narrower ring widths formation in the stems and governed higher sensitivity of the trees to air temperature in the periods of cambium reactivation, start and intensive growth.