(Picea abies) Norway spruce

Picea abies, the Norway spruce, is a species of spruce native to Northern, Central and Eastern Europe.[4] It has branchlets that typically hang downwards, and the largest cones of any spruce, 9–17 cm (3 1⁄2–6 3⁄4 in) long. It is very closely related to the Siberian spruce (Picea obovata), which replaces it east of the Ural Mountains, and with which it hybridises freely. The Norway spruce is widely planted for its wood, and is the species used as the main Christmas tree in several cities around the world. It was the first gymnosperm to have its genome sequenced, and one clone has been measured as 9,550 years old.

The Latin specific epithet abies means “fir-like”.

Description
Norway spruce is a large, fast-growing evergreen coniferous tree growing 35–55 m (115–180 ft) tall and with a trunk diameter of 1 to 1.5 m (39 to 59 in). It can grow fast when young, up to 1 m (3 ft) per year for the first 25 years under good conditions, but becomes slower once over 20 m (65 ft) tall. The shoots are orange-brown and glabrous (hairless). The leaves are needle-like with blunt tips, 12–24 mm (15⁄32–15⁄16 in) long, quadrangular in cross-section (not flattened), and dark green on all four sides with inconspicuous stomatal lines. The seed cones are 9–17 cm (3 1⁄2–6 3⁄4 in) long (the longest of any spruce), and have bluntly to sharply triangular-pointed scale tips. They are green or reddish, maturing brown 5–7 months after pollination. The seeds are black, 4–5 mm (5⁄32–3⁄16 in) long, with a pale brown 15-millimetre (5⁄8-inch) wing.

The tallest measured Norway spruce is 62.26 m (204 ft) tall and grows near Ribnica na Pohorju, Slovenia.

It can often be observed that the roots of spruces pushed over in a storm form a relatively flat disc. This is usually due to the rocky subsurface, a high clay content or oxygen-depletion of the subsoil and not to a preference of the trees to form a flat root system.
en.wikipedia.org

Picea abies, the Norway spruce, is a species of spruce native to Northern, Central and Eastern Europe. It has branchlets that typically hang downwards, and the largest cones of any spruce, 9–17 cm (3 1⁄2–6 3⁄4 in) long. It is very closely related to the Siberian spruce (Picea obovata), which replaces it east of the Ural Mountains, and with which it hybridises freely. The Norway spruce is widely planted for its wood, and is the species used as the main Christmas tree in several cities around the world. It was the first gymnosperm to have its genome sequenced, and one clone has been measured as 9,550 years old.

Kingdom:    Plantae
Division:    Pinophyta
Class:    Pinopsida
Order:    Pinales
Family:    Pinaceae
Genus:    Picea
Species:    P. abies

Description
Norway spruce is a large, fast-growing evergreen coniferous tree growing 35–55 m (115–180 ft) tall and with a trunk diameter of 1 to 1.5 m (39 to 59 in). It can grow fast when young, up to 1 m (3 ft) per year for the first 25 years under good conditions, but becomes slower once over 20 m (65 ft) tall. The shoots are orange-brown and glabrous (hairless). The leaves are needle-like with blunt tips, 12–24 mm (15⁄32–15⁄16 in) long, quadrangular in cross-section (not flattened), and dark green on all four sides with inconspicuous stomatal lines. The seed cones are 9–17 cm (3 1⁄2–6 3⁄4 in) long (the longest of any spruce), and have bluntly to sharply triangular-pointed scale tips. They are green or reddish, maturing brown 5–7 months after pollination. The seeds are black, 4–5 mm (5⁄32–3⁄16 in) long, with a pale brown 15-millimetre (5⁄8-inch) wing.

The tallest measured Norway spruce is 62.26 m (204 ft) tall and grows near Ribnica na Pohorju, Slovenia.

It can often be observed that the roots of spruces pushed over in a storm form a relatively flat disc. This is usually due to the rocky subsurface, a high clay content or oxygen-depletion of the subsoil and not to a preference of the trees to form a flat root system.

Range and ecology
The Norway spruce grows throughout Europe from Norway in the northwest and Poland eastward, and also in the mountains of central Europe, southwest to the western end of the Alps, and southeast in the Carpathians and Balkans to the extreme north of Greece. The northern limit is in the arctic, just north of 70° N in Norway. Its eastern limit in Russia is hard to define, due to extensive hybridisation and intergradation with the Siberian spruce, but is usually given as the Ural Mountains. However, trees showing some Siberian spruce characters extend as far west as much of northern Finland, with a few records in northeast Norway. The hybrid is known as Picea × fennica (or P. abies subsp. fennica, if the two taxa are considered subspecies), and can be distinguished by a tendency towards having hairy shoots and cones with smoothly rounded scales.

Norway spruce cone scales are used as food by the caterpillars of the tortrix moth Cydia illutana, whereas Cydia duplicana feeds on the bark around injuries or canker.

Taxonomy
Populations in southeast Europe tend to have on average longer cones with more pointed scales; these are sometimes distinguished as Picea abies var. acuminata (Beck) Dallim. & A.B. Jacks., but there is extensive overlap in variation with trees from other parts of the range.

Some botanists treat Siberian spruce as a subspecies of Norway spruce, though in their typical forms, they are very distinct, the Siberian spruce having cones only 5–10 cm long, with smoothly rounded scales, and pubescent (hairy) shoots. Genetically Norway and Siberian spruces have turned out to be extremely similar and may be considered as two closely related subspecies of P. abies.

Another spruce with smoothly rounded cone scales and hairy shoots occurs rarely in the Central Alps in eastern Switzerland. It is also distinct in having thicker, blue-green leaves. Many texts treat this as a variant of Norway spruce, but it is as distinct as many other spruces, and appears to be more closely related to Siberian spruce (Picea obovata), Schrenk's spruce (Picea schrenkiana) from central Asia and Morinda spruce (Picea smithiana) in the Himalaya. Treated as a distinct species, it takes the name Alpine spruce (Picea alpestris (Brügger) Stein). As with Siberian spruce, it hybridises extensively with Norway spruce; pure specimens are rare. Hybrids are commonly known as Norwegian spruce, which should not be confused with the pure species Norway spruce.

Cultivation
The Norway spruce is one of the most widely planted spruces, both in and outside of its native range, and one of the most economically important coniferous species in Europe. It is used as an ornamental tree in parks and gardens. It is also widely planted for use as a Christmas tree. Every Christmas, the Norwegian capital city, Oslo, provides the cities of London (the Trafalgar Square Christmas tree), Edinburgh and Washington D.C. with a Norway spruce, which is placed at the most central square of each city. This is mainly a sign of gratitude for the aid these countries gave during the Second World War. In North America, Norway spruce is widely planted, specifically in the northeastern, Pacific Coast, and Rocky Mountain states, as well as in southeastern Canada. It is naturalised in some parts of North America. There are naturalised populations occurring from Connecticut to Michigan, and it is probable that they occur elsewhere. Norway spruces are more tolerant of hot, humid weather than many conifers which do not thrive except in cool-summer areas and they will grow up to USDA Growing Zone 8.

In the northern US and Canada, Norway spruce is reported as invasive in some locations, however it does not pose a problem in Zones 6 and up as the seeds have a significantly reduced germination rate in areas with hot, humid summers.

The Norway spruce tolerates acidic soils well, but does not do well on dry or deficient soils. From 1928 until the 1960s it was planted on surface mine spoils in Indiana.
en.wikipedia.org

Big tree
Within most of the species' range, 100 cm dbh is quite a large specimen, partly because of the general rarity of old trees; outside of the northern forests, old forest is quite rare in Europe. The largest specimen of which I have received report is 214 cm dbh (1.3 m above ground), albeit tapering rapidly above that height (160 cm at 2.2 m), and is 56.2 m tall. The height of this tree is not recorded. It grows in the forest of Biogradska Gora National Park, Montenegro (full report and photographs: Räsänen 2008 and email, 2013.02.25). Mr. Räsänen (email 2010.12.25) states that "P. abies of 100 cm dbh are common in the old-growth remnants of the mountains of southern and central Europe. Picea abies and Abies alba are usually the largest trees, the former often having larger dbh, but the latter having larger volume due to slower stem taper." There is also record of a tree 153 cm dbh and 45 m tall from the Bagni di Mezzo, Trentino Alto, San Pancrazi, BZ, Italy (Corpo Forestale della Stato, a listing of big trees in Italy). The largest cultivated tree of which I have record is 147 cm dbh at Lingholm, Cumbria, UK (Mitchell et al. 1990).

The tallest specimen that has been reported using accurate measurement technique (tape drop or laser survey) is 62.26 m tall (above mid-slope) and 115 cm dbh (above top-slope). It is the Sgerm Spruce (Sgermova smreka) in Ribnica na Pohorju, west of Maribor, Slovenia, on private land Cthe Sgerm farm). It is estimated to be 250 years old, based on a ring count of a fallen nearby tree of similar size, and has been measured repeatedly using professional methods (including theodolite, laser, and direct tape drop); it was 51 m in 1938, 57.5 m in 1980, and 61.7 m in 1995 (Räsänen 2012). The second-tallest specimen is 59.2 m tall. This well-known tree is in Sächsische Schweiz National Park, Germany. The same park contains a number of other trees measured at over 50 m tall (Räsänen 2010).

Oldest
Tree LBG in the Bavarian Forest of Germany had a crossdated age of 468 years. It was collected by R. Wilson (RMTRR 2006).

In 2008, the popular media widely distributed news of a 9,550-year-old specimen of P. abies found in Sweden. The authors of the study, Leif Kullman and Lisa Öberg, actually asserted that they had found a clone that was as much as 9,550 years old, and this was not so astonishing; a variety of Picea species have been shown to reproduce by layering in habitat, and in fact clones of considerable age have been found at least in Picea engelmannii (Marr [1977]; at the alpine treeline on Niwot Ridge, Colorado) and Picea mariana (Légère and Payette [1981]; at the arctic treeline on the Ungava Peninsula, Quebec), and some tree clones have been found of even greater antiquity, as in the case of the Utah aspen (Populus tremuloides) clone shown to be at least tens of thousands of years old (DeWoody et al. 2008). No one had previously claimed to have found a Picea clone of such antiquity, but if anyone had done so, Kullman was a good candidate; he has a very long publication record on the subject of trees growing at their arctic and alpine limits. Kullman and Öberg's work was published in Kullman (2009) and in Kullman and Öberg (2009), and in several subsequent papers. However, Mackenthun (2016) critically examined Kullman and Öberg's analyses and found (a) no evidence of genetic continuity between dead wood remains discovered beneath the allegedly 9550-year-old tree and the living tree itself, and (b) no evidence of a clonal origin of the tree. The problems of finding clones of great age and inferring their continuity are substantial. When we look at arctic treelines around the world, we find that they sometimes experience primarily clonal reproduction (where the treeline species are capable of it), and sometimes sexual reproduction. The null hypothesis would be that sexual reproduction is episodic over time, occurring during climatic warm intervals that favor complete cone and seed development, with reversions to clonal reproduction during less favorable periods. Therefore, absent evidence to the contrary, the Swedish trees do not represent a 9,000-year-old clone, and the oldest clonal age in this species remains unknown.
www.conifers.org

https://en.wikipedia.org/wiki/Picea_abies