Korean aspen (Populus tremula var. davidiana or P. davidiana) is distributed in the Far East of Russia, China, Mongolia, and Korea. Although it is growing at their geographic range margin, it contains high level of genetic variation (Lee et al. 2011) and thus has high value in conserving biodiversity. However, population decline has already started possibly by climate change. Their number dwindles and will eventually disappear. In 2016, fine-scale spatial genetic structure was determined for small natural stands of Populus davidiana using AFLP markers. The species mainly regenerates from root suckers when forest is disrupted by fire or other damages. To conserve the remnant populations, National Institute of Forest Science, Korea selected 204 trees from wild populations. The selected trees were further screened in the nursery and 60 clones were chosen to establish ex situ conservation stands at 6 different locations in 1991 and 1992. As the stands aged, further 50 selections were made from the overlapping populations for establishment of new ex situ conservation in 2018 and 2019. Their performance at ages 6, 12, and 27 in the conservation sites were evaluated and the clones were ranked according to their growth performance including survival rate, height and diameter growth. The clones could be utilized in the future when the demand arises.
Both P. koreana and P. maximowiczii are growing in a few small patches in mountain valleys along the eastern part of the Korean peninsula. The populations of both species in Korea are at their geographical range margins and thus prone to extinction. In 2017, National Institute of Forest Science, Korea selected 105 trees of P. koreana and 57 trees of P. maximowiczii to secure genetic resources. Controlled crosses between the two species in the greenhouse also produced viable seeds that germinated normally. They are being grown in the nursery for further test.