|Scientific Name:||Pinus balfouriana|
Pinus balfouriana Balf. subspecies austrina Bruijn & J.Mastrog.
Pinus balfouriana Balf. variety austrina (Bruijn & J.Mastrog.) Silba
|Taxonomic Notes:||The two disjunct (sub)populations have been treated as distinct subspecies or varieties, with the southern population named P. balfouriana subsp. austrina. The differences are very small and include chemical characters (terpene compounds). The populations being disjunct, it is likely that some differences can be found, e.g. in leaf colour, and that these may be partly genetic in origin. Mostly the differences involve character gradients and would appear to be not truly distinct if wide sampling was done before analysing the data. Pinus balfouriana appears to be closely related to P. longaeva, a species which occurs to the east, also in isolated populations on high mountains. There are at least some consistent differences in the morphology between these two species, but it could as well be defended that there is only a single species with two or three subspecies or varieties. On the IUCN Red List Pinus balfouriana is treated as a distinct species without any varieties or subspecies.|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer/s:||Thomas, P. & Stritch, L.|
Based on comprehensive sampling of specimens held in herbaria in California and elsewhere, and the fact that very few if any stands of this species would have an area of occupancy (AOO) larger than 4 km² an AOO of only 136 km² was calculated. There are two main areas, separated by nearly 500 km, but the northern area has two locations, one with a much smaller subpopulation than the other. Fragmentation and number of locations therefore also fall within the threshold for Endangered; however, the population appears to be stable at present and there is no evidence of past decline within the last few hundred years. Climate change and air pollution (the latter only relevant to the southern subpopulation) are potential threats. It is therefore appropriate to list this species as Near Threatened (almost qualifies for listing under criterion B2ab).
|Range Description:||USA: mainly California, in two disjunct (sub)populations in northern (Klamath Mts.) and in southern (Sierra Nevada) California. One locality (metapopulation) of the northern (sub)population is just across the state border in Oregon (Lanner 2007).|
Native:United States (California, Oregon)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total number of mature trees is not known, but the population is fragmented, first by a gap of nearly 500 km between the northern and southern (sub) populations, and second by the fact that individual stands are (widely) scattered within these two areas. Numbers of trees in each of these stands vary between a few score to many hundreds. Regeneration and growth to maturity are extremely slow in most stands and may be episodic; this means that if little or no regeneration is observed in a stand at present this will not be evidence of decline. A tree that lives for several millennia only needs to produce offspring a few times in that whole period to replace itself and maintain the population.|
|Habitat and Ecology:||Pinus balfouriana occurs in the subalpine to alpine zones of the Klamath Mountains (the northern [sub]population) and of the southern Sierra Nevada (the southern [sub]population). In the north it is found at altitudes of between 1,600 m and 2,400 m a.s.l., in the south between 2,900 m and 3,700 m. Stands of this pine are very open and occur on dry, rocky, exposed high slopes and ridges, usually devoid of other significant vegetation. Stands may be pure or mixed with P. albicaulis, sometimes Juniperus occidentalis grows with it, too. Regeneration and growth are extremely slow and stands commonly look as if entirely composed of veteran trees of great age. Regeneration is probably episodal and may be linked with climatic cycles. Unlike its even longer lived 'cousin' P. longaeva, growing only 35-40 km to the east of the Sierra Nevada, little is known about the exact ages of some of the oldest trees, but they are likely to be more than 2000 years old.|
|Major Threat(s):||This species may be at risk in the long term from climate change if this is continuing to accelerate, possibly bringing in competitors and/or pathogens it may not be able to cope with. At present, both disjunct populations are well protected within National Parks and National Forest Wilderness Areas and unaffected by long-term effects of fire suppression in forests as the trees usually occur in remote subalpine locations where such measures have not been undertaken. It would be profitable to study the (aut-)ecology of this species in more detail in order to be able to estimate risks under various climate change scenarios. The southern (sub)population in Kings Canyon N.P. and Sequoia N.P. are subject to air pollution from major urban centres such as Los Angeles. The effect, if any, on this species is as yet unknown and needs to be researched.|
|Conservation Actions:||This species is mostly present within protected areas, including famous national parks like Kings Canyon and Sequoia N.P.|
|Citation:||Farjon, A. 2013. Pinus balfouriana. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 07 March 2014.|
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