Pine trees

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colspan=2 style="text-align: center; background-color: transparent" | Pine
Branch of a pine tree
colspan=2 style="min-width:15em; text-align: center; background-color: transparent" | Scientific classification
Missing taxonomy template ([//en.wikipedia.org/w/index.php?action=edit&title=Template:taxonomy/Pinopsida&preload=Template:Taxonomy/preload fix]):	[[Pinopsida ]]
Order	Pinales
Family	Pinaceae
Genus	Pinus
Species	P. trees
colspan=2 style="text-align: center; background-color: transparent" | Binomial name
Pinus trees
colspan=2 style="text-align: center; background-color: transparent" | Species
See text

Pine trees (Pinus) are a genus of trees in the family Pinaceae that are native to most of the Northern Hemisphere. Pines are evergreen, coniferous resinous trees (or, rarely, shrubs) growing 3–80 m tall, with the majority of species reaching 15–45 m tall. The bark of most pines is thick and scaly, but some species have thin, flaky bark. The branches are produced in regular "pseudo-whorls", actually a very tight spiral but appearing like a ring of branches arising from the same point. Many pines are long-lived, typically reaching ages of 100–1,000 years, some even more.

Description

Pines have four types of leaf:

• Seed leaves (cotyledons) on seedlings are borne in a whorl of 4–24.
• Juvenile leaves, which follow immediately on seedlings and young plants, are 2–6 cm long, green or often blue-green, and arranged spirally on the twigs.
• Adult leaves, which are long (fascicles), 2–45 cm long, and bundled in clusters of 1–6, depending on species.
• Scale leaves, similar to buds, are small, brown and not photosynthetic.

The cones of pines are the most recognizable feature, with each species having its own distinct size, shape, and color. Male cones are small, typically 1–5 cm long, and only present for a short period, shedding their pollen and then falling off. Female cones take 1.5–3 years to mature after pollination, with seeds dispersing shortly thereafter.

Ecology

Pines are highly adaptable and can grow in a wide range of environments, though they prefer well-drained soil and full sunlight. They are found in almost every type of habitat, from arid desert to cold mountain slopes. Pines are also important for wildlife, providing habitat and food for numerous bird species, mammals, and insects. Moreover, they play a critical role in the ecosystem by preventing soil erosion and influencing the water cycle.

Uses

Pines are commercially important. They are widely cultivated as timber trees, harvested for wood used in construction, furniture, and paper production. Pine wood is known for its strength and lightness, making it a preferred choice for many wood products. Additionally, pines are used for decorative purposes and landscaping. Furthermore, many pine species are valued for their resin, which is used in making turpentine and other chemical products.

Conservation

While many pine species are abundant, some are facing threats from habitat loss, invasive species, and climate change. Conservation efforts are crucial to prevent the decline of vulnerable and endangered pine species. These efforts include habitat preservation, legal protections, and research for better management practices.

See also

• List of Pinus species
• Coniferous forest
• Tree