AN IN-GROUND NATURAL DURABILITY FIELD-TEST OF AUSTRALIAN TIMBERS AND EXOTIC REFERENCE SPECIES .11. RESULTS AFTER MORE THAN 25 YEARS EXPOSURE

The condition of untreated heartwood specimens after more than 25 year s' exposure in an Australian field test of in-ground durability is dis cussed. Median specimen life (MEDSL) values are provided at all five s ites for 42 of the 77 timbers in test. Overall, decay contributed more to specimens becoming unserviceable than did termites. While six timb er species have not given MEDSL values at either of the two sites with greatest decay hazards, only two have not given such values at either of the two sites with greatest termite hazards. Only Eucalyptus wando o was common to both listings. Mean ratings are provided for any timbe r not having yielded a MEDSL, with such ratings showing that Sequoia s empervirens was in the best condition at the driest site. Sapwood of P inus radiata treated to 12 kg/m(3) with CCA was performing better than heartwood of any of the naturally durable species at each of the five sites.