Collecting and conserving the exceptional species, Taiwan Tanoak

Conservation Problem

Taiwan Tanoak (Lithocarpus formosanus), assessed as Critically Endangered, is restricted to Southern Taiwan and shows little evidence of natural regeneration as seed production appears to be poor and heavily predated.

Project Goal

The goal of this project is to secure the survival of this endemic, exceptional species in ex situ conservation collections in botanic gardens in Taiwan and through population reinforcement.

Why this species?

Taiwan Tanoak is found only on the Hengchun Peninsula in Southern Taiwan and is assessed as Critically Endangered on The Red List of Vascular Plants of Taiwan 2017.

The population in Hengchun is believed to consist of less than 50 mature individuals and there has been little evidence of natural regeneration in the recent past. Seed crops appear to be poor and there is evidence of seed predation by squirrels in the field. While the population of Taiwan Tanoak exists fully within Kenting National Park, the species is a well-known endemic and seeds may be harvested for inclusion in private collections. Germination of the seeds for conservation collections have been difficult in the past due to barriers to seedling development associated with the acorns having a thick coat and that the seeds require prolonged exposure to cold temperatures to break their dormancy.

Conservation methods involving living collections are needed for the conservation of this exceptional species as it cannot be adequately preserved long-term using current seed banking best practices.

Taiwan Tanoak (Lithocarpus formosanus). Credit: Jean Linsky/BGCI

What are we doing about it?

This GTC project complements on-going ecological research on the species by local universities and the Forestry Bureau. GTC has partnered with the Dr. Cecilia Koo Botanic Conservation Center (KBCC) and the Dept. of Forestry and Natural Resources at National Chiayi University (NCYU) to develop strategies for the ex situ conservation of the species and to develop ex situ collections which can be used to reinforce the species in the wild. Key objectives of the project include:

  • Securing the species in genetically representative ex situ conservation collections at KBCC and NCYU
  • Initiating propagation of individuals for wild population reinforcement
  • Improving local awareness of the threat of over collection of endemic species

KBCC staff and students from NCYU find L. formosanus in Southern Taiwan. Credit: Jean Linsky/BGCI

Key achievements

In 2018, data from the Taiwan assessment and consultations with NCYU were used to complete the global IUCN Red List assessment for this species which was assessed as Critically Endangered. A team from KBCC obtained permits from Kenting National Park and has surveyed the population in 2018 and 2019.  Cuttings were collected and trials to identify the best conditions for propagation have begun. Specific facilities for propagating woody cuttings have been created at KBCC to trial the effect of various conditions including humidity and temperature on rooting. Currently 200 cuttings are part of these trials. As another alternative to seed propagation, Prof. Yue Ken Liao and his team in the Tree Genetics and Physiology Lab at NCYU are working to develop tissue culture propagation protocols for the species.

Alternative methods such as tissue culture are being used to propagate L. formosanus. Credit: Dr. Yue Ken Liao/ NCYU

Cuttings of L. formosanus are growing at KBCC. Credit: Peter Tsai/KBCC

Contact details

For more information on this project, please contact globaltrees@bgci.org

Did you know?

There are more than 500 different oak species in the world. Find out about our work to protect the world’s most threatened oaks.