Picea engelmannii

Engelmann spruce (Picea engelmannii )

The Engelmann spruce (Picea engelmannii Syn, Picea glauca subsp. Engelmannii TMC Taylor 1959) is an evergreen tree species from the genus of spruce (Picea ) in the pine family ( Pinaceae ). It is native to western North America. It was first described by the botanist Charles Christopher Parry in 1863, which they named after the discoverer of the species, the physician and botanist George Engelmann.

Description

Habit

The Engelmann spruce is a fast-growing, evergreen tree, the plant height usually 24 to 30 meters, a maximum of up to 48 meters reached. The diameter at breast height is 76-100 cm. At the tree line, the species grows shrub-like or dwarf. The canopy is very vollholzig and narrowly conical. Free-standing trees are beastet to the ground. The branches are at an acute angle from the trunk, and hang at the ends about something. The bark is thin and scaly, leafing through circular plates 5-10 cm in diameter from. The bark of young branches is orange brown to gray- brown and hairy mostly closely. The species is up to 600 years old.

Foliage

The flexible needles are 25 to 32 millimeters in length and quadrilateral in cross-section. They are short -stalked and often pointed, but do not sting. The needle top is blue-green, with thin lines of stomata, the bottom blue and white with two wide stomatal lines. The needles are often covered by a whitish wax edition. If one grinds the needles they emit a peculiar smell.

Flowers, cones and seeds

The Engelmann spruce is monoecious - getrenntgeschlechtig ( monoecious ). It is reached puberty at about 25 years. The male cones are dark purple. The female cones are colored bright scarlet. The egg-shaped, ripen in August to early September of the year flowering light brown cones hang down and are 2.5 to 6 inches long. You are in the closed position about 1.5 inches thick and in the open state about 3 inches thick. They have thin, bendable and wedge-shaped cone scales with a length of 15 to 20 millimeters, the tips are often cut. Each pin is 8 to 20 dark brown to nearly black seeds, which are usually released in October. The seeds are 2-3 mm long, about 2 mm wide and have a 12 to 14 mm long pale brown wing. The thousand grain weight is around 3.3 grams.

Root

The Engelmann spruce is a shallow roots and therefore windthrow risk. The majority of the root system is located at depths from 30 to 46 centimeters. In deep soil, the root system can penetrate up to 2.5 meters in depth. The seedlings form a taproot, but soon gives way to the shallow root system. The Engelmann spruce is among other mycorrhizal partnerships with the panther mushroom ( Amanita pantheriana ), with C. geophilum, with the milk cap ( Lactarius deliciosus ), with the Blaublättrigen White Russula ( Russula delica ), with the cherry red storage Russula ( Russula emetica ) and Suillus a ruber.

Distribution and location

The Engelmann spruce is native to western North America. The distribution area extends from British Columbia and Alberta to northern California and to Arizona and New Mexico. It extends over nine U.S. states and two Canadian provinces. In addition, two isolated populations are in northern Mexico. In the Pacific Northwest of the United States, the natural distribution area is located east of the coastal mountains. It includes large parts of the Rocky Mountains. The Engelmann spruce grows rarely deeper at altitude 750-3300 meters, in the northwest part of its range. In many areas, she ventures up to the tree line. It is planted in gardens and parks worldwide because of their attractive appearance.

The Engelmann spruce is a tree species of cold - humid climate. The winters are long, cold and snowy with extreme temperatures of up to -45 ° C. The summers are short and cool contrast with maximum temperatures of 32 ° C. Frost may at any time give a year. The annual average rainfall is 640 mm. There are colonized medium enigmatic, well- drained, silty or clayey soils that have developed from basalt, andesite, rhyolite, shale, or limestone. A low growth indicates the type on nutrient-poor, dry, shallow soil and coarse-grained sands and gravels. She is a full sunlight, but is considered shade tolerant. The Engelmann spruce forms pure stands and mixed stands with the Subalpine Fir (Abies lasiocarpa ) of lodgepole pine (Pinus contorta ), the White -Russians Pine ( Pinus albicaulis ), with the Western White Pine (Pinus monticola ), with the Douglas Fir ( tremuloides Pseudotsuga menziesii ) and the American aspen (Populus ).

Use

The wood of Engelmann spruce is one of the easiest kinds of lumber in the United States. It is used for making paper, milled lumber and casings. The slow growth of wood occurring at higher altitudes Engelmann spruce is also used for the construction of acoustic guitars, violins and pianos. To a lesser extent Engelmann spruce trees are used as Christmas trees. Because of their attractive appearance it is a popular garden and park tree, which is cultivated worldwide. In some countries it is used in snow and wind protection belts. Forestry Attachments in Europe were disappointing due to Trägwüchsigkeit and strong knots. Many birds and small mammals feed on seeds and buds of Engelmann spruce. It provides winter protection, especially in the far north many animals.

Diseases and Pests

The most common fungal disease is the wood rot. The most important pathogens of root and crown rot are nigrolimitatus Phellinus, Inonotus tomentosus, Flammula Alnicola, the Brown cellar sponge ( Coniophora puteana ) as well as species of the genus honey mushrooms ( Armillaria ). Stem rot is often caused by the pine wood fungus ( Phellinus pini ), sanguinolentum by Haematostereum, Echinodontium sulcatum and the firs - layer mushroom ( Amylostereum chailletii ). The fungus Chrysomyxa arctostaphyli caused strain deformations Zopftrocknis and increase losses. The Zwergmistelart Arceuthobium microcarpum affects the Engelmann spruce, but is only found in the southern part of the range. Needle parasites do not represent serious threat for the type dar. The bark beetle Dendroctonus rufipennis mainly affects old or obsolete stocks and is considered economically significant. Growth losses and deformations of the strain caused by the caterpillars of the Choristoneura occidentalis Wicklerart, which feed on needles and buds of the plant.

The Engelmann spruce reacts due to their thin bark susceptible to forest fires.

System

The Engelmann spruce can be divided into two geographical subspecies, which have been described by some authors as varieties or even as a distinct species:

• The Engelmann spruce (Picea engelmannii subsp. Engelmannii ) is found throughout the area of ​​distribution, except as described in below.
• The Mexican spruce (Picea engelmannii subsp. Mexicana ( Martinez ) PA Schmidt) comes in two isolated populations in the high altitude mountains in northern Mexico before, in the Sierra del Carmen in Coahuila (Sierra Madre Oriental ) and on the Cerro Mohinora in Chihuahua (Sierra Madre Occidental). The Engelmann spruce in the mountains of southwestern New Mexico, southeastern Arizona and northern Mexico may belong to this subspecies.

The Engelmann spruce crosses in the overlapping areas of natural distribution areas extensively with the closely related White Spruce ( Picea glauca ) and, more rarely, with the Colorado Spruce (Picea pungens ). In the Picea engelmannii x Picea pungens hybrids also seems more of a natural cross between the white spruce and Sitka spruce (Picea sitchensis).

Swell

• Bulk, Weisgerber, Schuck, Long, vocal, Roloff: Encyclopedia of conifers. Nikol, Hamburg 2008, ISBN 3-933203-80-5, pp. 279-286.
• Entry at The Gymnosperm Database. (English )
• Entry in the Flora of North America. (English )