Gene flow and genetic diversity in eucalypt plantations and native forest in north coast New South Wales

In Australia, plantation eucalypts have the potential to form intra- and interspecific hybrids with native trees from the surrounding local forest. One of the major plantation species grown for hardwood timber production is Eucalyptus grandis Hill ex Maiden (flooded gum). There is public concern that gene flow (seed dispersal and pollen movement) between these plantations and locally growing native trees of the same species may have impact on the genetic composition of the native forest. Gene flow via plantation pollen and seed may influence the genetic composition of native forest by the production of viable progeny that can compete and survive to reproductive maturity. This study will initially address the first two of these issues, whether there are significant differences in genetic diversity in material used in plantations in relation to the same species in adjacent native forests and attempt to detect and quantify gene flow. Broad-scale population structure of E. grandis has been assessed using a chloroplast marker. Other genetic markers such as microsatellites will be used to determine genetic diversity in plantations and native forest, and measure gene flow parameters in a planting of E. grandis in the North Coast region of New South Wales.