A critically endangered Japanese birch species’ seeds have been successfully germinated in the United Kingdom.
Only 21 trees of the Betula chichibuensis species, commonly known as the Chichibu birch, remain in the wild, according to some estimates.
The Red List of Threatened Species says the population of this Japanese birch is unlikely to exceed 50 mature trees. The Chichibu birch has no close relatives, meaning the species is most likely very ancient.
Due to the size of the remaining population, scientists are fearful that it is too small to sustain itself. Part of the problem comes from the fact that the species is self-incompatible, meaning that it needs two of the trees to be close enough to cross pollinate.
In 2014, scientists from the University of Oxford Botanic Gardens traveled with a team from the University of Tokyo to the Chichibu birch’s remote habitat in the mountains of Central Honshu.
“It has got very, very low viability so we were very lucky that we were able to collect a lot of seeds,” Dan Luscombe, a dendrologist from the Forestry Commission’s Bedgebury National Pinetum and Forest, told BBC News. “Birch seeds shatter and shed everywhere, so once it has done that you will never find it.”
The team was able to collect about 1,000 seeds and from that about 100 seedlings have grown. These saplings will be spread across the UK so that various arboretums can attempt to grow the tree in different climates and soils.
Scientists also intend to plant a grove of Chichibu birch trees to provide an ongoing supply of seeds.