Pinus taiwanensis var fragilissima (Businsky) Farjon
A recently described variety known from one small area of Taiwan. It may meet the D criteria for Vulnerable but uncertainty about its population size and distribution has led to an assessment of Near Threatened.
Description
Taxonomic notes
Pinus taiwanensis is similar to P. hwangshanensis, P. luchuensis and P. densiflora and these species are closely related according to phylogenetic analyses using DNA sequence data. Recently, Businský (2003) revisited the morphology of some of these pines and separated some trees in Taiwan as a new species, Pinus fragilissima. Most of the characters evaluated are either similar to those of P. taiwanensis, or they show overlapping states. The seed scales are described as "thin" in the formal description and elsewhere as "fragile" but these are difficult to quantify and may be attributes of the other taxa as well. It also has somewhat longer leaves and only slightly longer seed cones.
Distribution
Endemic to Taiwan (Taitung Co, Kuan Shan massif).
Habitat and Ecology
The type locality is described as a steep ravine with side gullies, carved by the Hsinwulu River coming down on the eastern side of the Central Mountain Range of Taiwan. The pines were seen on rocky outcrops surrounded by steep slopes covered in angiosperm woodland, usually on the S to SW exposed sides, at altitudes between 500 m and 1,000 m a.s.l. A second locality was postulated by Businský (2003) to occur in the coastal Haian Shanmo Hills from a single herbarium specimen identified at C and a sighting of pines in the distance. The climate in this area is characterized by dry winters and wet summers.
Human Uses
No specific uses have been recorded.
Conservation Status
Global Status and Rationale
Nothing is known about population size and population trends. The habitat at the type locality seems of a kind unlikely to be under threat of logging or deforestation, and if limited to this and one other locality it is likely to be rare and restricted. If limited to two small localities, it could meet criterion D for Vulnerable. Since this is not known for certain it is assessed as Near Threatened until more information is available.
Global Threats
No specific threats are known although its currently known restricted distribution and possible small population size may make it susceptible to stochastic events.
Conservation Actions
Further research on the range, population size and trends and any potential threats is required. Taxonomic research is also required to resolve the relationship of this taxon to mainland plants.
References and further reading
Businský, R. 2003. Pinus fragilissima sp. nov. Novon 13(3): 281-288.
Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden
Hilton-Taylor, C., Yang, Y., Christian, T. & Farjon, A. 2013. Pinus taiwanensis var. fragilissima. The IUCN Red List of Threatened Species 2013: e.T191647A1991456. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T191647A1991456.en. Downloaded on 22 December 2016