%0 Articles %T Effect of waterlogging on boreal forest tree seedlings during dormancy and early growing season %A Wang, Ai-Fang %D 2017 %J Dissertationes Forestales %V 2016 %N 224 %R doi:10.14214/df.224 %U http://dissertationesforestales.fi/article/2010 %X

Increasing rain in winter with climate change may expose boreal forests especially on drained peatlands to winter or spring waterlogging. Information about the response of main forest species on soil waterlogging is important for improving predictions of forest productivity and assessing the demand for ditch-network maintenance. In this study, the aim was to find out the physiological and growth responses of one-year-old Norway spruce (Picea abies (L.) Karst.), silver birch (Betula pendula Roth) and pubescent birch (Betula pubescens Ehrh.) seedlings subjected to one-month waterlogging in late dormancy, and to find out the morphology, physiology and growth of both birch species subjected to one-month waterlogging in the early growing season.

Dormancy waterlogging (DW) led to a reduction of root volume in spruce, but did not affect dark-acclimated chlorophyll fluorescence or biomass of needles, stems and roots. Root biomass and root hydraulic conductance of silver birch were reduced but aboveground organs were not affected by DW. In pubescent birch stomatal conductance and net photosynthesis (Amax) were reduced by DW, however, root morphology and leaf, stem and root biomass was not negatively affected. In conclusion, these tree species tolerated one-month winter waterlogging well.

Growth waterlogging (GW) led to the reduction of stomatal conductance and Amax as well as leaf area in both birch species. Leaf contents of potassium, calcium, magnesium, manganese and boron were reduced in silver birch, whereas only calcium and magnesium contents were reduced in pubescent birch by GW. In pubescent birch, fine cluster roots, the occurrence of leaf trichomes and stem lenticels were increased by GW. However, silver birch did not show such acclimation to waterlogging. In conclusion, GW caused more negative effects to both birch species than DW. The morphological rather than physiological differences may explain why pubescent birch grows better in wet soil than silver birch.