Seedling Tolerance and PhasiologicalResponse to Short-Term Soil of ThreeEucalypts Species

摘要

The present paper involves a detailed comparison between the salt tolerance and physiological responseof three eucalypt species occurring within the Swan Coastal Plain, Western Australia. Eucalyptus gomphocephala DC (Myrtaceae) (common name ‘Tuart’) is restricted to the calcareous (limestone), brown or yellow sand of the coastal Spearwood dunes. Eucalyptus marginata Sm. (common name ‘Jarrah’) is a small tree on the porous, well-drained sandy soils of the Bassendean dunes Plain, and a much larger tree on the Darling Range. Corymbia calophylla (Lindl.) K.D. Hill & J. A. S. Johnson (common name ‘Marri’), and has a similar distribution to that of Jarrah, but is more common on wetter, well drained soils. This investigate implemented to find out the seedling tolerance of these three species to soil-induced stressor, namely salinity via addition of sodium chloride solution. Tolerance assessment measured changes in seedling growth, leaf allocation and leaf physiology after 70-80 days. Neither E. marginata and C. calophylla could tolerate the highest salinity (0.25 M NaCl solutions) with 9-13% survival, although E. marginata was clearly the least tolerant with 52% reduction in relative growth rate and a 88% in transpiration rates. E. gomphocephala was the most tolerant to salt stress in terms of survival and growth parameters.