TITLE:
Effects of Two-Year Variation in Soil Moisture Condition on the Development of Larch Root System in Eastern Siberia
AUTHORS:
Chisato Takenaka, Mie Miyahara, Takeshi Ohta, Trofim C. Maximov
KEYWORDS:
Larch, Soil Water Content, Root Distribution, Memory Effect
JOURNAL NAME:
American Journal of Climate Change,
Vol.5 No.2,
June
6,
2016
ABSTRACT: Recent climate changes, including an increase in precipitation, have affected tree physiology in eastern Siberia. We investigated the response of larch to wet and dry soil water conditions in pot experiments using larch seedlings grown under near-natural conditions in eastern Siberia over two growing seasons. Three patterns of wet- and dry-treatment combinations were applied over 2 years: wet treatments in 2006 and 2007 (WW treatment), dry in 2006 and wet in 2007 (DW treatment), and dry in 2006 and 2007 (DD treatment). After 1 year of treatment, no significant difference between the dry and wet treatment was found in root distribution and needle water content, except for the content of abscisic acid in roots. After 2 years of treatment, the DW treatment induced different tendencies in the gas exchange activity and in the needle biomass and root distribution of seedlings in comparison with WW treatments, despite the same water condition in 2007. We suggest a possibility that seedlings that experience drought stress might store some memory of drought that influences their physiology in the next growing season.