Broad implications of southern United States pine clonal forestry on planning and management of forests

Forest management activities are designed not only to meet the growing economic and commodity production needs of the human population, but also to maintain, conserve, and protect ecological and social values. This paper presents a set of broad implications of advances in tree cloning technology on forest management and planning, and how these advances relate to socio-economic and environmental concerns of a growing human population. The discussion is divided into topics that present socio-economic and political issues and topics that present environmental issues. On the production side, there are difficulties in initiating embryogenic tissue of cloned trees, and genetic variation may still occur during the tissue culture process. However, if production issues can be overcome, tree cloning techniques may possibly accelerate forest tree selection processes and reduce cloned seedling costs. The silviculture applied to clonal tree plantations may differ from current seed orchard-based plantations as it relates to site preparation, planting density, thinning opportunities, intermediate treatments, and final rotation age. These alternatives need to be assessed, yet it seems that clonal tree plantations could result in a higher rate of return for a forest investment, due to higher growth rates and more uniform tree characteristics. Plantations composed of cloned seedlings may also result in wood quality traits that are more consistent, although manufacturing processes may have to take into account higher levels of juvenile wood. Matching desired genetic characteristics of trees to site conditions is a challenge, although limited results suggest low levels of response differences of clonal plantations to changing environmental conditions. Maintaining genetic diversity and managing risks associated with mass infestation of trees from diseases and insects are other issues for forest management and planning. And politically, forest managers must address the notion that the natural genetic pool may become polluted. These issues are important at the stand and the landscape level, as losses (for example) due to disease can be catastrophic in forests with limited genetic variability. The potential impact of climate change might suggest conservation strategies that differ from tree breeding objectives for timber production, although fast-growing trees may help reduce CO₂ from the atmosphere, since biomass accumulation is related to the diameter and height of trees. Clonal forestry research efforts may also be valuable in identifying tree varieties that are more adaptable to climate change, should naturally-regenerated stands become affected on a large scale.