One of the world's rarest pines, confined to a single locality in Yunnan, China with only about 20 mature individuals.
Distribution
Known from a single location in China in Yunnan Province (Qiaojia Xian). The population consists of two small stands less than one kilometre apart. The most recent surveys (2010) indicate that there are 29 individuals of which 18 are coning trees. Three mature trees have been lost during severe weather in recent years.
Habitat and Ecology
This extremely rare pine grows on northeast and southwest facing slopes at altitudes ranging from 2000-2200 metres above sea level. Surrounding vegetation consists of disturbed open woodland with Pinus yunnanensis, Pinus armandii and various broad-leaved shrubs and trees. Regeneration is very limited.
Human Uses
The species has been reported to have been locally used for timber and firewood. It is not in cultivation outside of China.
Conservation Status
Global status and rationale
Critically Endangered D
This species has an extremely restricted range, with an estimated extent of occurrence of less than 4km2. Although there has been a slight reduction in the number of mature trees due to severe weather in 2008, there does not appear to be a continuing decline. Despite this its small population size means that it qualifies as Critically Endangered under criterion D.
Global threats
The small size of the population makes this species highly susceptible to stochastic events such as fires or extreme weather events. Genetic research that has been undertaken indicates very low levels of variability: inbreeding is a potential threat.
Conservation Actions
Pinus squamata was listed as a first class protected plant in 1999. The area where it occurs has also been declared a nature reserve and there is a strict ban on any felling. Some ex-situ work has been undertaken and a replanting programme is being planned. It has recently been include in Yunnan's programme for conserving plant species with extremely small populations (PSESP).
References and further reading
Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Li Xiang-Wang. (1992). A new series and a new species of Pinus from Yunnan. Acta Botanica Yunnanica 14: 259-260.
Wu, Z. & Raven, P.H. (eds). (1999). Flora of China: Vol.4. Cycadaceae through Fagaceae. Science Press (Beijing) & Missouri Botanical Garden (St. Louis).
Deng, L.L., S.J. Lu, G.S. Fan & X.W. Li (1995). Some community characteristics of Pinus squamata. Journal of Tropical and Sub-Tropical Botany 3(4):76-78.
Zhi-Yong Zhang, Yong Yan Chen, De Zhu Li (2005). Detection of low genetic variation in a critically endangered Chinese pine, Pinus squamata, using RAPD and ISSR markers. Biochemical Genetics 43(5/6):239-249.
Yang, Y. & Christian, T. (2013). Pinus squamata. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 13 July 2013.
Yongpeng Ma, Gao Chen, R. Edward Grumbine, Zhiling Dao & Weibang Sun (2013). Conserving plant species with extremely small populations (PSESP) in China. Biodiversity and Conservation. 22(3): 803-809
