Large seedlings of Pinus koraiensis to build Mother Forest

Korean pine, Pinus, Pinus, evergreen coniferous trees. It is mainly distributed in Xiaoxing'an Mountains and Changbai Mountain in China. Pinus koraiensis forest is the top community in this area, which plays an important social, ecological and economic role. In the early days of the founding of New China, in order to meet the needs of economic construction, excessive cutting of Korean pine trees was carried out, resulting in a large reduction of Korean pine trees. at present, there are only about 5 million mature Korean pine trees. Therefore, the massive, rapid and high-quality construction of Pinus koraiensis mother forest is of great significance for the restoration and development of the top community of Pinus koraiensis forest in Xiaoxinganling and Changbai Mountains.

Pinus koraiensis has a strong preference for light and slightly likes shade in the seedling stage. with the increase of tree age, the light requirement increases gradually and grows rapidly on fertile slightly acidic sandy soil. Under suitable climatic conditions, the natural Korean pine began to bear fruit when it reached 35 years old, and the artificial Korean pine timber forest began to bear fruit when it reached 25 years old. Through the mother forest built by Korean pine seedlings, the range of nutrient absorption increased and began to bear fruit after 18 years, and the effect was very obvious. Therefore, according to practical experience, the technology of building mother forest with large seedlings of Pinus koraiensis is introduced as follows:

1. Afforestation site selection: the plain of Xiaoxinganling and Changbai Mountains or the mountain with slope less than 25 degrees, and the slightly acidic sandy loam with soil thickness of more than 30 cm.

2. Soil preparation: the fixed point hole-like soil preparation is adopted, with a row spacing of 3 meters × 3 meters, a hole diameter of 80 cm and a depth of 40 cm. The time of soil preparation is determined according to the climatic conditions of different areas, which usually begins in mid-October and ends before the soil is frozen. The soil is prepared prematurely, and the soil is easy to harden after rain and sunlight. When the soil preparation is too late, the soil has been frozen, and it is more difficult to prepare the soil. In addition, soil preparation should not be done in spring, because after soil thawing in spring, soil water evaporates, permeates and loses too much, which is not conducive to the survival of large seedlings of Pinus koraiensis.

3. Seedling selection: Pinus koraiensis, which is 7-9 years old, and has changed the bed twice. The seedling standard is as follows: the ground diameter is more than 0.8 cm, the seedling height is more than 35 cm, the main root grows more than 20 cm, and the lateral root system is more than 20. It is required that the trunk is straight, the terminal bud is full, the color is normal, there are no diseases and insect pests, and there is no damage to the main root, lateral root system, trunk and lateral branches.

4. Seedling raising and packaging: within 7 days before planting, fill the roots of selected seedlings with wet straw or soak them with rooting powder and water absorbent, then wrap the roots and crowns with plastic bags, and place them in a wet, shady and cool place.

5. Planting: when the soil is thawed in mid-April. Remove the packing of the seedlings, remove the packaging of the roots of the seedlings, plant the seedlings in the holes that have been made, stretch the roots and straighten the seedlings, at the same time, evenly apply 0.25 kg of nitrate and phosphorus fertilizer in each hole, fill the soil layer by layer, keep your feet down and water thoroughly, and then cover with 2 cm thick leaves or weeds to preserve moisture.

6. tending of young forests: after planting large seedlings of Korean pine, intercropping tall crops such as sorghum or corn between rows 50 cm away from the seedlings, first, they can shade the Korean pine, and second, the Korean pine can absorb some nutrients from the fertilizer applied to the crops. Artificial weeding is used when weeding, and the use of chemical herbicides is prohibited.

7. Rodent damage control: the mother forest built by large seedlings of Pinus koraiensis is very prone to rodent damage in spring and autumn, and rodent poison can be applied in early April and late October every year.