Abstract
Plantations have many environmental benefits, for example, plantations sequester carbon during the growing cycle, they can be used to revegetate marginal agricultural land and increase biodiversity and they produce sustainable timber as an alternative to imports and harvesting native forests. However there are environmental risks that need to be assessed, especially where plantations are close to existing native forests. The risks of genetic pollution by new plantation species need to be assessed for these species to be widely adopted by industry and environmental groups. This chapter reports on a series of discrete studies on environmental risks, benefits and opportunities for plantations. We examined the risks of genetic pollution from Corymbia hybrids into native forests (sections 5.1 and 5.2). In particular, some Corymbia hybrids may present risks to bees and the environment due to their attractiveness to stingless bees and we report on this risk (5.2). We also examined opportunities for breeding in these studies for Corymbia (5.1). Similarly we examined Eucalyptus breeding systems to identify risks of genetic pollution and opportunities for breeding (section 5.3) and Khaya breeding systems to assess possibilities for breeding (section 5.4). Climate change implications were addressed in terms of the risks to plant stock from climatic variability and change, both temporally and spatially (section 5.5). This included scenario modelling of climatic conditions including extreme event analysis. This research was conducted in collaboration with other researchers from the Plantation Hardwoods Research Fund project "Characterising Wood Properties for Deployment of Elite Subtropical and Tropical Hardwoods", and this allowed a wider range of sites and species to be tested.