Abstract:
Four red oak species including Nuttall oak (Quercus nuttallii), Shumard oak (Q. shumardii), Water oak (Q. nigra), Willow oak (Q. phellos) and one white oak species, Live oak (Q. virginiana) from Southern USA were introduced for establishing plantations at different sites and soil types in Yangtze River Delta of China. When 1-or 2-year-old bare-root seedlings were planted after a long distance of transportation, the survival rates of Nuttall oak, Shumard oak, and Water oak were higher than 94%, while the survival rates of Willow oak and Live oak were 76% 81% and 42% 50% respectively. Obvious differences existed among species in root and shoot growth habits, phenology and pest occurrence at young stage. For the four red oak plantations established on paddy soil, the mean annual DBH increments and height increments after 8 10 years ranged from 0.96 to 1.76 cm and 0.8 to 1.33 m with the reserved density of 900 1 500 trees per hectare. But the mean annual DBH increments and height increments of stands on hill with red-yellow soil ranged from 0.64 to 1.01cm and 0.57 to 0.78m, respectively. The Live oak stands planted with 2-to 4-year-old seedlings with clod-ball on coastal saline soil had a survival rate of higher than 87%, and the mean annual DBH increments and height increments at the age of 7 9 were 0.78 1.13 cm and 0.59 0.75 m respectively with the density of 1 110 3 900 trees per hectare. All the trees of the 5 oak species begun to bear fruit at the age of 6 9. The research showed that the 5 oak species had good adaptability to natural conditions in Yangtze River Delta. Water oak, Nuttall oak, Shumard oak and Willow oak can be applied for construction of plain landscapes and ecological stands, and Live oak has broad prospects for coastal protective forest.