Genetic guidelines for tree species and perspectives on the conservation and sustainable use of forests

Forest conservation and the sustainable use of forests are important issues for biodiversity conservation, water supply, disaster prevention, recreation, carbon stock, and wood resources for human use. Reforestation for restoration, greening and laying down carbon stock on degraded land such as disaster areas and poor plantations has recently become a very active process, carried out by not only governments but also NPO and NGP groups and as a company social contribution activity (CSR) in Japan. However, when plantation materials of different origins are used, they sometimes cause a problem because they produce hybrid offspring with native individuals and then offspring cannot always adapt to the local environment. For non-experts, planting guidelines are necessary when collecting seeds for planting and determining planting sites. Genetic guidelines for seedling transfer in 43 Japanese tree species was proposed using DNA information. However, these guidelines are just the first step in achieving the conservation and sustainability of forests. Thus, to facilitate the management of healthy forests for conservation and sustainability, I propose to use the existing genetic guidelines for tree species and revise them to add further important data regarding their phenotypes and eco-physiological alterations under global climate change. In this review, I discuss how forests have established and historical human disturbance of forests in Japan, the mechanisms of formation of genetic structure within species, and the importance of genetic guidelines for planting.