Pinus torreyana ssp. torreyana
|Scientific Name:||Pinus torreyana ssp. torreyana|
See Pinus torreyana
|Taxonomic Source(s):||Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.|
|Red List Category & Criteria:||Critically Endangered B1ab(ii,iii,v)+2ab(ii,iii,v) ver 3.1|
|Reviewer(s):||Thomas, P. & Stritch, L.|
Urbanization is encroaching on the mainland population (ssp. torreyana) with the effect that trees outside the Torrey Pines State Park are still disappearing. There is also an acute risk of a major fire wiping out a large part of the population, a risk that is known to increase for various reasons where housing developments are near the population in a potentially fire-prone area. The present decline is probably slow, but ongoing. The extent of occurrence and area of occupancy are both very small (20 km2 and 4 km2 respectively) and the whole area can be treated as a single location. The mainland subspecies is therefore listed as Critically Endangered.
|Previously published Red List assessments:|
|Range Description:||Endemic to southern California (San Diego Co., on the coast north of San Diego), USA.|
Native:United States (California)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There are an estimated 3,000-3,500 mature trees in the population.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Pinus torreyana subsp. torreyana is a relict taxon now confined to littoral habitat on the coast (up to 1.6 km inland) of southern California. It grows from immediately above the high tide mark to about 180 m a.s.l. on rocky or sandy slopes. On these sites it seems dependent on the daily fog that comes in from the ocean in the afternoon, mitigating the heat of the sun and the resulting excessive evapo-transpiration. It grows with a sparse chaparral and few other trees; in ravines sometimes accompanied by a few oaks (Quercus sp.) and Arbutus menziesii.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||30|
|Use and Trade:||Torrey Pine is not used as a timber tree; at present the two disjunct populations are protected by law. It is in cultivation in California in gardens and some arboreta, but rare elsewhere. In the better growing conditions of gardens it can grow to a large tree; a specimen in New Zealand was 45 m tall with a d.b.h. of 1.5 m in 1982 (Grimshaw and Bayton 2009: 626).|
|Major Threat(s):||The small population on the mainland that constitutes this subspecies is in part (southern subpopulation) legally protected in the Torrey Pines State Park. However, the small overall size, fewer than 3,500 mature trees covering ca. 320 ha in two subpopulations, and close proximity to major urban development, puts the subspecies highly at risk of destructive events such as fires, pest epidemics and diseases. Trees outside the reserve are often not adequately protected from development; they are sometimes incorporated in urban landscaping and sometimes felled (A. Farjon personal obs. 1992). Urbanization outside the reserve is ongoing, with expanding housing projects encroaching on the population of Torrey Pines. The permits required to fell a tree do not seem to have stopped this happening. It is expected that this will result in continuous, slow loss of mature trees unless all are incorporated in a protected area and a total ban on felling is enforced.|
|Conservation Actions:||One of the two subpopulations is protected within a specially created reserve (Torrey Pines State Park), where collecting and other activities detrimental to the pines are strictly prohibited and regulations enforced. The Torrey Pine is protected by a city tree ordinance in Del Mar, near the native habitat, and construction projects and citizens need an approved permit before they can remove any trees. It is strongly recommended to create a reserve for as many trees as possible in the second (northern) subpopulation, and stop housing projects from encroaching on the natural range of this pine. Although conservation measures for this taxon seem to be in place at present, growing this taxon more widely as an ex situ backup is strongly recommended; it is also an interesting taxon to grow and requires a mild climate with warm, sunny summers and (near) absence of frost in winter.|
Farjon, A. 2010. Conifer Database (June 2008). In: Species 2000 & ITIS Catalogue of Life: 2010 Annual Checklist (Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin T., Baillargeon G., eds). Reading, UK Available at: http://www.catalogueoflife.org/.
Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Griffin, J.R. and Critchfield, W.B. 1972. The distribution of forest trees in California. USDA Forest Service, Research Paper PSW-82 (reprinted with supplement, 1976). Pacific Southwest Forest and Range Experiment Station, Berkeley, CA.
Grimshaw, J. and Bayton, R. 2009. New Trees: Recent Introductions to Cultivation. Kew Publishing, Kew.
IUCN. 2013. IUCN Red List of Threatened Species (ver. 2013.1). Available at: http://www.iucnredlist.org. (Accessed: 12 June 2013).
Lanner, R.M. 1999. Conifers of California. Cachuma Press, Los Olivos, California.
|Citation:||Farjon, A. 2013. Pinus torreyana ssp. torreyana. The IUCN Red List of Threatened Species 2013: e.T34015A2840365.Downloaded on 29 August 2016.|
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