Pinus canariensis

Canary Island pine (Pinus canariensis)

The Canary Island pine (Pinus canariensis ), also called Canary Island pine, is a species of the genus of pine (Pinus ) within the family (Pinaceae ). It is endemic to the Canary Islands. It is the most economically important tree species in the Canaries.

• 5.1 hybrids

• 6.1 Notes and references

Description

Habit

The Canary Island pine is reached from 50 to 100 centimeters of an evergreen tree, the plant height 15-25 meters and diameter at breast height. In the southwest of Tenerife, a 60 meter high tree found with a trunk diameter of 265 centimeters. Thus, the Canary Island pine is the largest extant pine in the Old World. Free-standing trees have a broad and irregularly shaped crown. In dense stands it forms a narrow pyramidal crown. Young shoots are 6 to 13 millimeters thick. She is able to cast out, for example, after forest fires from the stumps, trunks and branches. The lifetime is given as 250 to 300, in some cases up to 600 years.

Buds and needles

The large and thick winter buds are ovoid to cylindrical in shape, pointed and not resinous. They are covered by reddish brown scales. These scales are 10 to 16 millimeters long and 4-5 mm wide and have a free recurved tip. The edge is provided with long eyelashes.

The very flexible needles are close to the long shoots. At 10 to 20 millimeters long spurs they are three. They are 15 and 30 inches long and about 1 mm wide. On young trees, they are colored green grass blue green and old trees. On older trees, they are also strikingly shiny and hang over. The needles are pointed and finely toothed on the edges. The cross section is three-sided, and on each side there are 1-3 stomata. The needles remain around 2 to 3 years on the tree. Use the long needles is the kind capable of fog clouds " comb out ", resulting in an additional precipitation through condensation. There are small areas reached rainfall of around 2,500 mm per year.

Flowers, cones and seeds

The Canary Island pine is monoecious - getrenntgeschlechtig ( monoecious ). The flowering period extends from March to April. At the base of one-year long shoots can be up to 150 male cones on an area of ​​about 10 by 6 inches. At the beginning of the flowering season they are greenish yellow in color and about 3 inches long. For fading out they turn reddish. The pollen is yellow. The female cones are usually solitary or in pairs, rarely in whorls at the tips of long shoots. They are greenish and turn red after bloom down. The short- stalked cones are about 7-18 inches long and 4-8 inches thick. They ripen in the fall of the 2nd to 3rd year and are then colored shiny brownish red. The cone scales are about 4 inches long and 2 inches wide. Regarding the PTO If two types are distinguished. In the first type, the sterile scales remain on the branch. In the second type, the entire journal from the branch resolves. The gray -brown to blackish, often mottled seeds are about 12 millimeters long and 6 millimeters wide. They are obovate and have a 12 to 25 millimeters long wings, whose edge is slightly wavy. The thousand-seed weight is 62-169 gram .. The seedlings usually have 7-9 long and thin seed leaves ( cotyledons )

Bark

The thick gray to reddish brown Stammborke is deeply furrowed and torn into scaly plates. In older trees the bark from up to 50 layers may consist. The bark of young branches is yellow and bare. She turns in 2nd year matt brown. In forest fires the bark but not crusty charred by such fire protection mechanism drives the Canary Island pine after forest fires again.

Root

The Canary Island pine forms a strong taproot that reaches deep into the ground. There are strong lateral roots formed, which remain close to the surface only on shallow soils, but can also grow very deep to deep soils. The way goes with many fungal species, including 14 species of crack mushrooms ( Inocybe ), a mycorrhizal partnership.

Wood

The resin rich dark brown heartwood is surrounded by a bright yellowish sapwood. The annual rings are clearly visible. The wood of the Canary pine is compared to other Mediterranean pine species native heavy, hard and very durable. The sapwood has in a moisture content of 12%, a bulk density 0.60 to 0.75 g / cm ³, a compression strength of 53 N / mm ² and a bending strength of 116 N / mm ². The heartwood at a moisture content of 12 %, a bulk density of 0.92 to 1.14 g / cc, a compressive strength of 47 N / mm ² and a flexural strength of 124 N / mm ².

Distribution and location

The Canary Island pine is endemic to the Canary Islands. They are found on the islands of Gran Canaria, Tenerife, La Palma, La Gomera and El Hierro. The natural circulation area covers approximately 50,000 acres of forest land. On the islands of Fuerteventura and Lanzarote the type is completely missing. It is planted in the northern Mediterranean, the southern United States, South America, Australia and New Zealand as an ornamental tree. In North and South Africa it is planted as a forest tree.

The Canary Island pine is a tree species of the dry subtropical Mediterranean climate, which is characterized in the Canaries mainly by the northeast trade winds. In winter, the moisture is uniform, and in summer it is a constant heat and drought before. The mean annual temperatures are 11-19 ° C. The extreme temperatures range from -6 to 40 ° C. Extensive forests grow mainly in the clouds of mist zone. The species requires a annual precipitation of 300 mm. There are colonized mainly Andosol - Cambisol and volcanic raw soils. She is a pioneer tree species on young volcanic soil. The pH should be below 7.5. They are found at altitudes 300-2300 m. In Central Europe, the Canary Island pine is not hardy.

An accompanying plants are called in deeper layers of tree heath (Erica arborea ) and the Gagel tree ( Myrica faya ). In the middle zone, at altitudes 1400-1900 meters, the Geißkleeart Cytisus proliferus prevails. It is at higher altitudes from Sticky glands broom ( Adenocarpus viscosus ), of Adenocarpus foliolosus and from Teide broom ( Cytisus supranubius ) replaced. Especially on forest fire and cleared areas takes the Beinwellblättrige Rockrose (Cistus symphytifolius ) increased as a Companion Plant.

Use

The precious wood of the Canary pine is used in many ways. Among others, it is used as construction, carved wood and for the production of equipment and charcoal. It is controversial how important the " combed " by the needles fog condensation for the water balance of the islands is, as a large portion of this water runs off superficially .. The needle litter was formerly used for packaging of cultivated banana Musa acuminata on the Canary Islands. It is still used as a bedding agent in cattle sheds and chopped as compost.

Diseases and Pests

In the natural habitat the Canary Island pine is hardly threatened by diseases and pests. Occasionally the needles are infected by a rust fungus in the genus Coleosporium. Planted stocks in India proved to be very susceptible to blister rust pathogen Cronartium the himalayense. In South Africa, the root rot -causing fungus Rhizina undulata and the needle mushroom Dothistroma pini were detected. In the United States a weak resistance to rust Cronartium comandrae was detected. Stocks in Italy there are less often affected by damping-off than other pine species. On infestation with the Kiefernschildlaus ( Matsucoccus Josephi ) the nature responded in Israeli Attachments with the formation of a Wundperiderms that prevented further development of the pest. The species is particularly susceptible to the pine processionary moth ( Thaumetopoea pityocampa ).

Especially in more than 40 years held it always comes back to forest fires, which are mostly caused by humans. The bad rotting needle litter thereby promotes the spread of fire. Old trees survive these fires due to their thick bark mostly intact. They are also able to drive out of new branches and stems with long shoots.

System

The Canary Island pine is allocated within the genus of pine (Pinus ) in the subgenus Pinus, section Pinus pinaster and the subsection. The chromosome number is 2n = 24 The most closely related species is native to the Himalayan Pinus roxburghii the. Probably the two species have the same ancestors. Based on DNA analyzes, a phylogenetic relationship with the pine (Pinus pinea ) was detected. In the natural habitat different phenotypes can be distinguished on the basis of shape -branching, crown formation and crust formation, suggesting a genetic variation. Particularly high morphological variation in the pin, depending on the amount, temperature and humidity. It is still unclear whether the individual populations represent different races in the Canary Islands.

Hybrids

An artificial crossing succeeded so far only with Pinus roxburghii, but intolerance reactions were recognizable. Thus, the seed of the hybrids were only half as heavy as the seeds of the parental species.