3种引进的耐盐观赏树种耐盐能力比较

以从美国引进的观赏树种秋橄榄（Elaeagnus umbellata）、沙枣（E．angustifolia）和美国白蜡（Fraxinus americana）2年生苗为材料，在高含盐量（0．8％）、中含盐量（0．6％）、低含盐量（0．2％）3种不同盐地上进行耐盐性试验．结果表明：3种树种的成活率、株高、地径、冠幅、分枝5项指标随盐浓度的增加都呈递减趋势，其中美国白蜡在高盐地的成活率较高，耐盐性较强．生理指标显示3种植物都具有较好的耐盐性，且耐盐性由强到弱为美国白蜡〉秋橄榄〉沙枣，其中秋橄榄、沙枣适合种植于中低盐地，美国白蜡可种植于中高盐地．

Comparative Analysis of Salt Tolerance in Three Species of Introduced Ornamental Plants

By studying 2 year-old seedlings of Elaeagnus umbellate, E. angustifolia and Fraxinus americana introducted from the USA, we identified their survival rate, stem length, ground diameter, crown diameter and branch under different saline land （0.8%, 0.6% and 0.2%）. The results show that with the increasing salinity, the 5 indices in these seedlings decreased. E americana shows a higher survival rate and wider salt tolerance. Physiological indicators show that all of the three species of plants show strong tolerance to salt. The strength of salt tolerance can be placed in descending order as E. angustifolia〉E, umbellata〉F, americana. Comprehensive evaluation of salt tolerance suggests that all these 3 ornamental plants have strong salt tolerance, good planting and good ornamental value. E. angustifolia and E. umbellata are suitable for planting in middle and low saline land, whereas F. americana develops well in middle and high salt soil.