Pinus clausa

Sand pine ( Pinus clausa )

The sand pine ( Pinus clausa ) is a plant of the genus pine (Pinus ). It is native to North America.

• 5.1 varieties

Description

Habit

The sand pine grows depending on the location as a shrub or as a broad crown and reaches stature heights 23-26 meters, in rare cases up to 31.4 meters. The diameter at breast height is 51-66 centimeters. The crown tip is flattened. The trunk can be straight and erect to curved depending on location. The branches are horizontal to slightly upright. The root system of the seedlings composed of numerous, very small Lateralwurzeln. No description via the root system of old trees.

Foliage

The flexible needles are 5-9 inches long and about 1 mm wide. The short shoot are two deep green and slightly rotated about the longitudinal axis of needles. They remain between three and four years on the tree.

Flowers, cones and seeds

The sand pine is reached puberty at around 5 years. The dark orange male cones are densely packed. The laterally inserted female cones are stalked strong. The nearly symmetrical, dull egg-shaped and short -stalked cones are 5-9 inches long. When ripe they are dark yellow-brown. They often are arranged in several whorls. The seed maturation takes about two years. When var immuginata they are released in September of the second year while in the journal clausa var only when intense heat, such as a forest fire, open. After dismissing the seeds, the cones are almost round. The almost triangular and winged seeds are approximately 6 mm long seeds with wings. The average number of seeds per pin is at var clausa 37 and at var immuginata 42 The thousand grain weight is around 6 grams.

Bark

The bark is in the lower trunk gray to gray-brown, the upper part of the tree rather reddish to reddish brown and breaks into plates. It is thick up to 1.5 centimeters. In thin stems is smooth and gray. The bark of the slender branches is colored purple to reddish brown.

Wood

The yellowish heartwood is surrounded by a wide and bright sapwood. The light wood is soft and brittle. The annual rings are clearly visible and the transition between early and late wood takes place abruptly. Resin canals are mainly found in the early wood. The dry density is about 0.38 g / cm ³.

Distribution and location

The distribution area is divided into two sub- areas. The greater part area is located in Central and East Florida 26-30 ° north latitude. It covers approximately 100,000 hectares, of which a large part in the Ocala National Forest near the city of Ocala is located. The remaining trees grow in Florida in a narrow strip along the east coast of St. Augustine south to Fort Lauderdale. The second and smaller part area covers approximately 40,000 hectares and extends from the coast of Northwest Florida and Alabama from Apalachicola to Pensacola. These stocks extend up to 40 kilometers into the interior.

The sand pine is a full sunlight and grows in a climate characterized by hot, rainy summers and mild, relatively dry winters. The annual precipitation is 1350-1520 mm. In the area of ​​distribution of the var clausa fall from April to October average of 50 to 75 mm of precipitation. The extreme temperatures are between -17 ° C and 42 ° C. The location of deep, well drained and nutrient-poor sands are preferred. The pH should be in the acidic to strongly acidic range. Var. clausa usually forms brunette mixed stands with the Virginia - oak (Quercus virginiana), the Myrtenblättrigen oak (Quercus myrtifolia ), with Quercus chapmanii, saw palmetto ( Serenoa repens ) and Persea borbonia due to the depending of forest fires opening the spigot. Since usually missing a herbaceous ground flora cover lichens of the genus Cladonia the forest floor. The var immuginata forms uneven- and loosely structured mixed stands with the fork - oak (Quercus laevis), Quercus incana and various cacti species.

Diseases and Pests

As the most important abiotic factor prove harmful forest fires, especially in the spring when the water content of the needles and the low resin content is very high. The fungus Phytophthora cinnamomi attacks the roots of the sand pine seedlings and leads to severe outages. The pine fire sponge ( Phellinus pini ) and Cronartium quercuum infest this kind, however, are not a threat represents the two bark beetle species Ips calligraphus and Ips grandi collis affected mainly by drought or mechanical damage weakened old trees of var immuginata. Needle grazing by Buschhorn sawflies of the genus Neodriprion occurs in two varieties particularly in premolars stocks. The corn borer type Dioryctria amatella cause feeding damage to cones and branches.

Use

The wood of the sand pine is mainly used for paper production. However, it is also well as firewood. One kilogram of stem wood has a calorific value of about 19,900 kJ. The var immuginata is grown as Christmas trees due to their short and densely needled branches.

System

Within the genus of pine (Pinus ), the sand - pine of the section and subsection Trifoliae Contortae is assigned. It is closely related with Pinus virginiana.

Varieties

Because of the two geographically separate areas of distribution, two varieties are distinguished:

• Pinus clausa var clausa, also called Ocala race, coming in Central and East Florida before in mostly the same old pure stands. Old trees bear many closed cones of different ages can be opened only after a forest fire. Therefore, the species name clausa stirred what "closed" means.
• Pinus clausa var immuginata, also Chocta - whatchee race called, is on the coast of Northwest Florida and Alabama before in mostly premolars and uneven- stocks. The cones have a normal opening behavior.

Swell

• C. Frank Brockman: Trees of North America. New York: St. Martin 's Press, 2001, ISBN 978-1-58238-092-6. .
• Bulk, Weisgerber, Schuck, Long, vocal, Roloff: Encyclopedia of conifers. Nikol, Hamburg 2008, ISBN 3-933203-80-5, pp. 357-362.
• Description and classification of species on Conifers.org. The Gymnosperm Database. (English )