Strategy for screening eucalypts for saline lands

摘要

We present a new approach for selecting seed sources of Eucalyptus to be grown on saline land. We evaluated our method using 22 seed sources, 11 tree-form species and 11 mallee-form species. We found that the commonly used strategy of selecting seed sources on the basis of average productivity was inappropriate, as average productivity was poorly correlated with the relationship between productivity and salinity that was actually observed. Using our new approach, we categorized seed sources as salt-sensitive or salt-tolerant based on the strength of the observed relationship between salinity and productivity. Seed sources defined as sensitive were associated with relatively large (−24.8 to −64.2%) productivity losses, while the changes in productivity for tolerant seed sources ranged from −17.1 to 10.5%. On average, reductions in height due to increased salinity were about 30% greater for sensitive seed sources than tolerant ones, although the effect was smaller for mallee-form and greater for tree-form seed sources. The difference between sensitive and tolerant seed sources was similar after 1, 2 and 4 years of growth. Keywords ‘Geonics’ EM-38 meter - Height - Mallee-form eucalyptus - Salinity response - Screening - Tree-form eucalyptus