Influences of Prolonged Soil Flooding on Leaf Gas Exchanges and Growth of Populusdeltoides and Taxodiumdistichum Seedlings

The effects of 450-days of flooding on morphological and gas exchanges responses were investigated under controlled conditions for Populus deltoides (colon 77.51) and Taxodium distichum seedlings. Seedlings were subjected to three outdoor treatments: not flooded (control), flooded to 3 cm above the soil surface (shallow flooded), and flooded to 15 cm above the soil surface (deep flooded). Flooding had no significant effect on the height growth and survival of T. distichum seedlings during 450-day period, but survival and height growth of deep flooded seedlings in P. deltoides were decreased. Under flooding conditions diameter growth increased in T. distichum and decreased in P. deltoides. Leaf area and biomass accumulations reduced by flooding in both species. Flooding reduced net photosynthesis, stomata conductance and transpiration in both species. Overall, even though at flooding status in both species some morpho-physiological variables reduced but due to satisfactory of some other variables like survival, height growth and shoot biomass in 450 days of experiment, possibility of growth and survival of seedlings will be excepted.