Seedling Tolerance and Phasiological Response to Short-Term Soil of Three Eucalypts Species

Abstract

The present paper involves a detailed comparison between the salt tolerance and physiologicalresponseof three eucalypt species occurring within the Swan Coastal Plain, Western Australia.Eucalyptusgomphocephala DC (Myrtaceae) (common nameTuart �) is restricted to the calcareous (limestone), brown or yellow sand of the coastal Spearwood dunes.Eucalyptus marginataSm. (common nameJarrah �) is a small tree on the porous, well-drained sandy soils ofthe 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 investigateimplemented 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. NeitherE. marginataand C. calophyllacould tolerate the highest salinity (0.25 M NaCl solutions) with 9 -13% survival, althoughE. marginatawas 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.