Rhododendron liboense, a distinctive species occurring in the Maolan National Nature Reserve, Libo County, Guizhou Province, China, belongs to the subgenus Hymenanthes. This evergreen tree, reaching 2–5 m in height, is highly ornamental, with pink, bell-shaped flowers c. 8 cm in diameter that bloom during April–May. The species was categorized as Critically Endangered on the Botanic Gardens Conservation International Red List of Rhododendrons (2011) and the Red List of China’s Higher Plants (2013). A survey confirmed its extreme rarity, identifying only three wild populations with a total of 85 individuals (Huang et al., 2018, Oryx, 610–611).

Starting in 2022, supported by the Forestry Research Project in Guizhou Province (Qian Lin Ke He 2021-08) and Guizhou Provincial Key Technology R&D Programme (Qian Ke He Zhi Cheng [2023] YiBan 035), integrated conservation strategies for R. liboense were implemented, including in situ protection, ex situ relocation and reintroduction. In October 2025, the outcomes of these measures were assessed by evaluating in situ population size, the survival rate of ex situ seedlings and the performance of reintroduced plants. A 10 ha in situ conservation zone was established in 2022 to protect the Donghua population, demarcated with fencing and boundary markers. Recent monitoring indicates this population has increased by 15 individuals since 2018, raising the total number of naturally distributed individuals to 101. From 2022 to 2024, three ex situ conservation sites were established at the Guizhou Botanical Garden, Guizhou State-owned Longli Forest Farm and Qiannan Botanical Garden, with 70 3-year-old seedlings planted at each site. The survival rate of these seedlings was 70–80%, resulting in a total of 162 surviving individuals across the three sites. Simultaneously, in March 2022–2024, three rounds of reintroduction were conducted within the Maolan Nature Reserve, with each round involving the planting of 180 seedlings into limestone microhabitats similar to the original habitat, using native soil as the substrate. The overall survival rate of reintroduced seedlings was 22%, contributing 121 new individuals to the wild and leading to the establishment of two new populations. Collectively, these actions have resulted in comprehensive protection efforts for this Critically Endangered species.

However, survival rates from initial reinforcement plantings were low. We found that most surviving seedlings were in karst stone troughs and crevices. This finding will be applied to select better future planting sites, aiming to improve survival, increase the number of wild individuals and expand the population.

Rhododendron liboense in flower.