1, big tree type

Most kinds of trees are tall and straight, reaching a height of 45 meters, DBH 1.5 meters when they are mature, with good materials and many columns. Korean pine, the "king of wood" in the northeast of China, tall Pinus ponderosa (up to 75 meters) widely distributed in the west of North America, the fastest growing pine radial pine originated in the coastal area of California, slash pine originated in the southeast of the United States, Caribbean pine originated in the Caribbean of America, and Pinus densiflora widely distributed in the west and north of Eurasia. , are famous timber trees.

2. There are many kinds

There are nearly 80 kinds of pine trees in the world, such as Pinus tabulaeformis and Pinus sylvestris var. Pinus sylvestris var. mongolica, Pinus densiflora, Pinus massoniana, Pinus taiwanensis, Pinus Bashan, Pinus Taiwan Province, Pinus tabulaeformis, Pinus yunnanensis, Pinus Simao, Pinus elliottii, Pinus koraiensis, Pinus ovata, Pinus qiaosong, Pinus kwangsiensis, Pinus tabulaeformis and Pinus Taiwan Province.

3. Widely distributed

Pines are widely distributed. Among the pine trees native to China, Pinus densiflora. Pinus sylvestris var. mongolica, Pinus yunnanensis and Pinus sylvestris var. mongolica have the lowest requirements for heat, while Pinus koraiensis has the lowest requirements for heat. Pinus densiflora, Pinus tabulaeformis, Pinus bungeana, Pinus taiwanensis, Pinus taiwanensis, Pinus taiwanensis and Pinus Bashan are tree species in warm temperate and subtropical high-altitude areas, while Pinus massoniana, Pinus yunnanensis, Qiao Song and Pinus Simao are more distributed in south and south Asia. The requirement of five-needle pine on wet conditions is generally higher than that of two-needle pine, but it also varies from species to species.

4. Long service life

Pine trees are strong and have a long life. Experts found that the life span is generally more than 1200 years. There is a metaphor in China that "the life span is longer than that of southern pine trees", which also shows that the life span of pine trees is longer. On the cliff at the entrance to the back hall of Nanshan Temple in Guixian, Guangxi, stands a young pine with more than 3,000 years old. The fruiting of pine trees is also different. Some varieties can bear a small amount of fruit in 5 ~ 6 years, and 15 ~ 20 years increases significantly (Pinus massoniana, Pinus tabulaeformis, Pinus yunnanensis, etc. ). Some tree species bear fruit very late, such as Korean pine. Under natural forest conditions, it takes 80 ~ 140 years to bear fruit.

5. Strong adaptability

Pine trees have strong adaptability to land environment, can tolerate low temperature of -60℃ or high temperature of 50℃, can grow in bare mineral soil, sandy soil, volcanic ash, calcareous soil, limestone soil and various soils from calcareous soil to red soil, and are drought-resistant, barren and fond of sunshine. Some pine trees, such as black pine introduced to China from Japan, have strong salt resistance.

6. High value

Pine trees are extremely valuable. Wood can be used for buildings, telephone poles, sleepers, columns, bridges, farm tools, appliances, furniture and other purposes. The cellulose content of various pine trees is about 50-60%, and the lignin content is 25-30%. It is one of the important raw materials in pulp and paper industry and can also be used as firewood. Because of its majestic posture and long life, it also has important ornamental value. In addition, pine trees also have extremely high medicinal value.

Extended data:

There are more than 80 kinds of pine trees in the world, which are not only diverse, but also widely distributed, such as Pinus tabulaeformis and Pinus sylvestris var. mongolica. Pinus sylvestris var. mongolica, Pinus thunbergii and Pinus densiflora distributed in several provinces of North China and Northwest China, Pinus massoniana, Pinus taiwanensis, Pinus alpine, Pinus Bashan, Pinus Taiwan Province and Pinus brevifolia in North America. Most of them are the main tree species for afforestation in barren hills in China.

Pine trees are wheel-shaped branches with long internodes, thin and flat branchlets or slightly bent downward, and slender needles in bundles. Its crown looks loose but not compact, and the word "loose" is an image description of its crown characteristics. So "pine" is a tree with a loose crown. Pine trees are strong and have a long life.

Pine trees can grow on all kinds of soil. Because of the low ash content of needles, they can tolerate poor soil, but when planted in loose and fertile soil, their productivity is high. Pine trees in humid areas are mostly suitable for acidic soil. Some pine trees, such as Pinus bungeana and Pinus tabulaeformis, can adapt to the soil with high calcium content and high pH value.

The roots of pine trees are symbiotic with mycorrhizal fungi. The hyphae of ectomycorrhiza mainly form a sheath around the short lateral roots, which is beneficial to the absorption of water and nutrients by the roots. Therefore, inducing mycorrhizal development is very important for the success or failure of some pine afforestation. Most pine trees can't grow on saline-alkali land, so they can't grow near the seashore. But some pine trees, such as black pine introduced into China from Japan, have strong salt tolerance.

References:

Baidu encyclopedia-pine tree