Evaluation of flooding tolerance in two-year-old seedlings of common ash (Fraxinus excelsior L.)

The aim of this study was determining the physiological and morphological responses of two-year-old common ash (Fraxinus excelsior L.) seedlings to flooding stress. For this purpose¡ seedlings of common ash were examined in a completely randomized design for 102 days under continuous flooding¡ temporary flooding treatment (for 60 and 42 days drainage¡ respectively) and control. Stomatal conductance¡ transpiration¡ and photosynthesis rate were progressively decreased by flooding while all seedlings survived at the end of flooding. Also¡ flooded plants were able to adequately recover their physiological activities. In addition¡ height¡ root length¡ leaf area¡ and biomass accumulation of seedlings decreased under flooding conditions (particularly in continuous flooding). Diameter growth on the other hand¡ increased in seedlings subjected to temporary flooding. Overall¡ the results showed that two-year-old seedlings of F. excelsior had a suitable response to flooding stress until day 60. After 42 days drainage¡ the physiological characteristics of the seedlings were recovered. Generally¡ on the basis of the findings in this research¡ it is expected that F. excelsior can be used for the purpose of restoration of lowlands and wood production in areas subjected to periodic flooding.