RIDGLEY, TASMANIA — RESEARCHERS at the Associated Pulp and Paper Mills (APPM) research station here are searching for the perfect tree.It has to grow fast, be frost resistant, and deliver a high pulp yield. Once researchers find the right characteristics, these will be cloned into the tree farms APPM is planting in areas it has cleared or on farms or grassland. The research is centered around a hybrid of two eucalyptuses, the shining gum and the Tasmanian blue gum. "The shining gum has superior frost tolerance while the Tasmanian blue gum seems to have a higher pulp yield," says David de Little, a research manager for APPM. APPM, working with the Commonwealth Scientific and Industrial Research Organization, is now evaluating trees planted 10 years ago. "We can certainly pick the top trees," says Mr. de Little. Because it takes 10 years to see the results of generational changes, the cloning has been an important part of the research. By cloning, APPM can incorporate the genetic gains rapidly. "If we had to put them into a seed orchard, we would have to wait another 10 years to get seed off them," says de Little. Last year de Little began an extensive field trial for the hybrids. There are now 37 acres of clonal trees. "Preliminary research indicates some degree of success," he says.