Reaction of Larix gmelinii roots under low soil temperatures in northern parts of central Siberia [Russian Federation]
2002
Prokushkin, S.G. (V.N.Sukachev Inst. of Forest, Krasnoyarsk (Russian F.)) | Prokushkin, A.S. | Stasova, V.V. | Mori, S. | Sakamoto, Y. | Quoreshi, A.M. | Koike, T.
This study examined how permafrost soils affect morphology, anatomy and metabolism of Dahurian larch (L.. gmelinii) roots at five different sites in northern parts of Central Siberia. Field monitoring using custom-made rhizotrons showed that there were three different periods for seasonal root growth. Root growth was most active in the latest season (mid-July to late August) when soil-temperature and moisture were favorable. Use of an artificial watering treatment revealed that the larch root was developing resulted in even root growth throughout the growing season. The larch trees developed superficial root systems on permafrost soils and each root stretched into the warm mounds of soil. Moreover, L. gmelinii generated adventitious roots following litter accumulation. Comparative analysis of anatomic root structures between L. gmelinii growing on the permafrost and L. sibirica from southern region showed some interspecific differences; e.g. prevalence of other fine root tips, in the number and diameter of growth roots, inter-cell spaces and cell layers. Analysis of biochemical characteristics of fine roots of L. gmelinii demonstrated that the level of free amino acids on colder soils was 1.5-2 times higher than on warmer soils. Conversely, protein nitrogen content was 1.5-2 times larger in warmer soils. These anatomical, morphological and physiological features were discussed from the viewpoint of the adaptive growth characteristics for L.. gmelinii against severe climate conditions in the permafrost region.
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