Photosynthetic and stomatal responses of Larix kaempferi seedlings to short-term waterlogging

The effects of short-term waterlogging on net photosynthesis, stomatal conductance and shoot water status of 2 year old seedlings of Larix kaempferi (Lamb.) Carr. were studied under controlled environmental conditions. Waterlogging for 8 days induced significant stomatal closure and reduced net photosynthesis. After 3 days of waterlogging, stomatal conductance was reduced to 35% of that of non-waterlogged plants, and net photosynthesis was reduced to 25% of the pre-waterlogged level. At the beginning of waterlogging, slight shoot dehydration was observed. However during the latter stage of the waterlogging shoot dehydration disappeared and stomatal conductance and net photosynthesis increased. No adaptive morphological changes to waterlogging were observed in the stems and roots. Recovery of stomatal conductance and net photosynthesis after drainage was not observed within 11 days.