European black pine, Austrian pine, Crimean pine. German: Schwarzkiefer, Schwarzföhre. Bulgarian: Cheren Bor. Serbian: Crni Bor. Turkish: Karaçam.
A member of Pinus sect. Pinus.
Like the other two widespread European pines, P. sylvestris and P. mugo, this species has received an excessive number of described names, a consequence of very narrow subspecific and varietal concepts applied notably in France and parts of Eastern Europe. In some areas virtually every small clump of trees has been given its own scientific name, many of them invalid under the International Code of Nomenclature for Algae, Fungi and Plants, giving P. nigra the appearance of an extremely variable species. Although it is variable, it is not markedly so compared to other widely distributed conifers worldwide; across its entire range, it shows a level of genetic diversity similar to many other Pinus species (Scaltsoyiannes et al. 1994). The eight or more subspecific names accepted by Vidakovic (1974) and some others is not reflected in usage among other conifers with similar levels of variability.
The most prominant variation in P. nigra occurs between trees from the eastern and western halves of its range, which differ strongly in foliage (Christ 1863, Koehne 1893, Delevoy 1949, Dallimore et al. 1967, Vidakovic 1974, Christensen 1993) and genetic structure (Scaltsoyiannes et al. 1994) and have been assigned to different subspecies. The (typical) eastern subspecies, found in Austria, the Balkans, Greece, Turkey, Cyprus and the Crimea, has stout, rigid needles usually 1.5-2.0 mm thick, which persist for 4-7 years on the tree. Their needle anatomy shows 3-6 layers of hypodermal cells with strongly thickened cell walls. The western (salzmannii) subspecies, from Italy, S France, Corsica, Spain and the Atlas Mountains of NW Africa, has slender, flexible needles 0.8-1.5 mm thick which persist for 2-4 years on the tree. In needle anatomy they have only 1-2 layers of hypodermal cells with thin cell walls.
The difference in foliar morphology between the subspecies reflects a more severe winter climate in the eastern populations. Winter temperature minima are markedly lower in this more continental climate, with absolute minima sometimes falling below -30°C in most of the eastern subspecies' range. Minima in the western subspecies' range rarely fall as low as -20°C. Forestry trials in cold areas of the USA (Lee 1968, Wheeler et al. 1976) have consistently found eastern origins to be significantly more cold-tolerant than western origins.
The two subspecies are separated by a large range gap across the Adriatic Sea and the Po valley of Northern Italy, leaving unoccupied over 600 km of apparently suitable habitat in the southern Alps. Given the range disjunction and the differences in morphology and adaptation, the eastern and western groups meet accepted criteria for the rank of subspecies in conifers (e.g. Christensen 1987) and are here so treated. The eastern populations form the typical subspecies, subsp. nigra, with the western populations classified as subsp. salzmannii (Dunal) Franco (Christensen 1993, 1997).
Within both subspecies, further minor geographic variation occurs, mainly in cone size and colour, needle length and bark colour, which may be treated at varietal level. There is considerable overlap and clinal gradation in these characters (Vidakovic 1974), and the populations are only reliably distinguishable on the basis of means compiled from the measurement of many trees. This is confirmed by isoenzyme and allozyme studies (Nikolic and Tucic 1983, Scaltsoyiannes et al. 1994), which show high within-population genetic diversity accounting for 94% of the diversity (Scaltsoyiannes et al. 1994), with most alleles distributed across the range of each subspecies. Individual trees are therefore not always assignable to a variety without prior knowledge of their origin. Each of the subspecies is divided here into three varieties.
Subsp. nigra J.F. Arnold (this page), the thick-leaved eastern subspecies, comprises:
See also subsp. salzmannii (Dunal) Franco, the thin-leaved western subspecies.
A tree to 25-45 m tall and 1-1.8 m dbh. Stem straight; bark on entire trunk thick, scaly-plated, grey-brown, to pinkish on some very old trees. Crown with stout level branches with upswept tips; dense ovoid-conic when young and becoming rounded to flat-topped with age. Branching uninodal. Shoots green at first, becoming orange-buff by the end of the first summer, densely leaved. Buds ovoid-acuminate, red-brownish with whitish fringes to scales, usually with some patchy grey-white resin. Leaves in fascicles of two, (6-) 8-15 (-18) cm long, stout, 1.5-2 mm thick, dark green, often curved and slightly twisted, margins finely serrulate; persistent for 4-7 years; leaf sheath blackish-grey, 10-15 mm. Leaf anatomy shows 3-6 layers of thick-walled hypodermal cells. Male cones 10-15 mm, yellow. Cones (4.5-) 5-10 (-12) cm long, conic, symmetrical or nearly so, green ripening grey-buff to shiny yellow-buff; mature in October- December, 20 months after pollination, opening ovoid-conic from February to April, and falling soon after seed shed or a year or two later; scales rounded, flat to protuberant, with a transverse ridge and a minutely mucronate dorsal umbo. Seeds dark grey, 5-6 mm, with a 15-22 mm wing.
The varieties may be distinguished as follows:
var. nigra: leaves 6-14 cm, cones dull grey-buff, 4.5-9 cm, bark on old trees grey.
var. caramanica: leaves 8-16 cm, cones bright yellow-buff, 5-10 cm, bark on old trees orange-pinkish.
var. pallasiana: leaves 10-18 cm, cones dull grey-buff, 7-12 cm, bark on old trees orange-pinkish.
Subspecies nigra occupies the mountains of the northeastern Mediterranean region. Its constituent varieties are distributed as follows:
Var. nigra in Austria, Romania, Slovenia, Croatia, Yugoslavia, Macedonia, Albania and Bulgaria, at low to moderate altitudes (200-1200 m), in southeast European continental climates with some summer rainfall; intergrading with var. caramanica in the south.
Var. caramanica in Greece, Turkey (southern or possibly all), and Cyprus, at moderate to high altitudes (800-2000 m) in strictly Mediterranean climates with no summer rainfall.
Var. pallasiana in the Crimea and the Black Sea coast of the Caucasus, at low to moderate altitudes (200-1200 m), with some summer rainfall; northern Turkish populations may belong here.
The species is also naturalized in Canada: Alberta, British Columbia, Ontario, and Québec; and USA: Illinois, Maine, Massachusetts, Michigan, Missouri, New Jersey, New York, Ohio, Pennsylvania (PLANTS database 2009.03.31), and probably Washington (pers. obs.). Hardy to Zone 5 (cold hardiness limit between -28.8°C and -23.3°C) (Bannister and Neuner 2001).
I have few data for trees in habitat. Räsänen (2012) reports that the Durmitor National Park in Montenegro has many pines 45 m tall, with the highest measured being 47.4 m (laser measurement) and 94 cm dbh. He measured other pines at Durmitor up to 133 cm dbh.
Some exceptional trees have been planted in the U.K. A specimen of var. caramanica at Beaufort Castle, Highland, has a dbh of 137 cm and is 41 m tall. One at Beaupont Park, Sussex, is 167 cm dbh and 37 m tall (Mitchell et al. 1990). I have also heard of a Turkish specimen 22 m tall and 178 cm dbh, found by a Dr. Karaca (of the Karaca Arboretum), but have no further information.
Widely used in Europe and the US as an ornamental, and in forestry for shelterbelts, and for timber production in areas too cold for the faster- growing subsp. salzmannii. USDA hardiness zone 5. Very tolerant of chalk and limestone, and also of urban pollution - perhaps the most pollution-tolerant of any pine.
Crna Poda in Durmitor National Park, Montenegro, may be the finest remaining old-growth P. nigra forest. Besides P. nigra, it also hosts fine stands of Abies alba, Picea abies; and even Pinus mugo on the high peaks (Räsänen 2012).
Arnold, J. F. 1785. Reise nach Mariazell in Steyermark. Wien (p. 8).
Christ, H. 1863. Uebersicht der Europäischen Abietineen (Pinus Linn.). Verhandlungen der Naturforschenden Gesellschaft Basel (n.s.) 3: 541-557.
Christensen, K. I. 1987. Taxonomic revision of the Pinus mugo complex (Pinaceae). Nordic Journal of Botany 7: 383-408.
Christensen, K. I. 1993. Comments on the earliest validly published varietal name for the Corsican Pine. Taxon 42: 649-653.
Christensen, K. I. 1997. Gymnospermae (Pinophyta). Pp. 1-17 in: Strid, A. & Tan, K. (eds.), Flora Hellenica vol. 1. Koeltz, Königstein.
Delevoy, G. 1949. A propos de la systématique de Pinus nigra Arnold. Travaux Station Recherches de Groenendaal série B. 12: 1-37.
Koehne, B. A. E. 1893. Deutsche Dendrologie. Stuttgart.
Lee, C. H. 1968. Geographic variation in European Black Pine. Silvae Genetica 17: 165-172.
Mitchell, A.F., V.E. Hallett, and J.E.J. White. 1990. Champion trees in the British Isles. Forestry Commission Field Book 10.
Nikolic, D., and N. Tucic, N. 1983. Isoenzyme variation within and among populations of European Black Pine (Pinus nigra Arnold). Silvae Genetica 32: 80-89.
Räsänen, K. 2012. Crna Poda – a new height record for European black pine. www.ents-bbs.org/viewtopic.php?f=385&t=4725, accessed 2013.02.24. The article includes many photographs.
Scaltsoyiannes, A., Rohr, R., Panetsos, K. P., & Tsaktsira, M. 1994. Allozyme frequency distributions in five European populations of Black Pine (Pinus nigra Arnold). Silvae Genetica 43: 20-30.
Vidakovic, M. 1974. Genetics of European Black Pine (Pinus nigra Arnold). Annales Forestales 6/3: 57-86.
Wheeler, N. C., Kriebel, H. B., Lee, C. H., Read, R. A., & Wright, J. W. 1976. 15-Year performance of European Black Pine in provenance tests in North Central United States. Silvae Genetica 25: 1-6.
Dida, M., F. Ducci, and G. Zeneli. 2001. Black pine (Pinus nigra Arn.) resources in Albania, in Forest Genetic Resources No. 29. www.fao.org/DOCREP/004/Y2316E/y2316e0d.htm, accessed 2011.02.25.
Last Modified 2013-02-24