Abstract: One year old Taxodium distichum seedlings were grown in pots with varied soil water and salt (NaC1) levels (alone and in combination) under greenhouse conditions to determine their effects on the growth and biomass allocation of the seedlings. The results showed that there were significant effects of soft salt and water contents on the relative height growth, relative stem diameter growth, biaomass increment and allocation, shoot/root ratio, seedling survival, ratio of branch to stem area, ratio of leaf mass to stem area, and ratio of leaf mass to branch area. According to the biomass increment, relative height growth and relative stem diameter growth, 20 treatments were classified into 3 groups by means of systematic cluster analysis. The first one was the treatments waterlogging, flooding, waterlogging + 0.15% NaC1, flooding + 0.15% NaC1, and waterlogging + 0.3% NaC1, which had a high growth, the second one was the treatments flooding + 0.45% NaC1, flooding + 0.3% NaCl, 75% of field capacity, and 75% of field capacity + 0.15% NaCl, which had a medium growth, and the last onewas the treatments 50% of field capacity, 50% of field capacity + 0.15% Nat1, waterlogging + 0.45% Nat1,25% of field capacity, 25% of field capacity + 0.15% NaC1, 75% of field capacity + 0.3% NaC1, 75% of field capacity + 0.45% NaC1, 25% of field capacity + 0.3% NaC1, 50% of field capacity + 0.3% NaC1, 50% of field capacity + 0.45% NaC1, and 25% of field capacity + 0.45% NaC1, which had a poor growth.

Key words: Quercus variabilis, trunk diameter, sap flow, water regime, meteorological factor.