Native to USA and Mexico. Even though this species is fire-adapted and to some extent fire-dependent it is still at risk.
Distribution
Recorded from USA: California (Coast Ranges); and Mexico: Baja California Norte. Pinus coulteri has a relatively limited area of occupancy (816 km2) that is within the threshold for Vulnerable but is known from more than 10 locations. Subpopulations are severely fragmented.
Subpopulations are severely fragmented and there is a general decline in the population trend
Habitat and Ecology
In California, Coulter Pine is prominent in the southern California Mixed Conifer Forest, especially at the lower limit of this forest type, where it merges into fire-prone chaparral. In Baja California it is also a tree of mixed chaparral, together with Quercus chrysolepis, or growing on granite boulder formations around Laguna Juárez. Its altitudinal range is from 300 m to 2,100 m a.s.l. (in Mexico 1,200-2,150 m). It is most commonly found on dry, rocky slopes and ridges, where competition from other trees is minimized. The climate is of a Mediterranean type with winter rain and long, hot and dry summers.Phenology: pollen dispersal occurs in May-June
Human Uses
Coulter Pine has no particular commercial value as a timber tree and its seeds, although edible, are not harvested for consumption. It is quite frequently represented in parks and arboreta in southern Europe and themilder parts of the British Isles, and this pine has also been introduced as an amenity tree in Australia and New Zealand. In California it is also planted in parks and large gardens, often in small groups. No cultivars are known of this pine and it is apparently rarely grown and sold by horticultural nurseries. The impressive cones are often collected and displayed as curiosities in private houses as well as schools and other public buildings
Conservation Status
Global Status
Near Threatened
Global Rationale
Pinus coulteri has a limited area of occupancy. It may also be adversely affected by fire management policies. Although there are no data to quantify a rate of decline in the past or present, it is inferred that continuous and/or increased suppression of forest fires will in the long term lead to such a decline. It is therefore appropriate to flag this species as Near Threatened (it almost qualifies for a threatened category under criterion B2ab(ii,iii,v)), while closer monitoring is required.
Global Threats
This fire-adapted and fire-dependent (to some extent) species could be at risk from forest succession leading to dominance of less fire-adapted trees in those (usually urbanized) areas where fires are being prevented or put down. Conversely, too frequent fires could destroy seedlings and saplings before they reach a reproductive age. Thus fire control, if not conducted with the ecology of this species in mind, could work against the long-term survival chances of Pinus coulteri. It is unknown whether this situation has already led to decline of the population.
Conservation Actions
This species occurs in several protected areas. However, a more adequate management of forest fires affecting this species than conducted at present in most areas is required. Research into the effects of fire suppression on regeneration of Coulter Pine and competition from other species is required.
References and further reading
Burns, R.M. and Honkala, B.H. 1990. Silvics of North America. USDA, Forest Service, Washington, DC.
Chardon, N.I., Cornwell, W.K., Flint, L.E., Flint, A.L. and Ackerly, D.D., 2015. Topographic, latitudinal and climatic distribution of Pinus coulteri: geographic range limits are not at the edge of the climate envelope. Ecography, 38(6),590-601.
Huttunen, S., Bytnerowicz, A., Arbaugh, M.J., Bent, K., Karhu, M. and Tuohimaa, P., 2014. Diagnostics of Epistomatal Wax of Californian Pine Needles, and Their Association with Ozone-Caused Chlorotic Mottle. American Journal of Plant Sciences, 5(12), 1733-1744.
Minnich R.A., Goforth B.R., Paine T.D. (2016) Follow the aater: extreme drought and the conifer forest pandemic of 2002–2003 along the California Borderland. In: Paine T., Lieutier F. (eds) Insects and Diseases of Mediterranean Forest Systems. Springer, Cham
