Pinus elliottii (Latin name: Pinus elliotii)
I. Economic Characteristics and Market Prospects
S. elliottii is native to the southeastern United States. Because of its early growth, strong adaptability, good dryness and straightness, good quality of wood, and high turpentine yield, it is one of the tree species introduced successfully in our province. Wood can be used for construction, pulp and fiber materials, and it is also an excellent material for sleepers, poles and pillars. Standing wood is rich in pine resin and can be processed into turpentine. In addition, the tree posture is upright and graceful. The trunk is straight and can be used for ornamental tree species.
Second, the ecological characteristics
Pine wet light, warm temperature. Vertically distributed in the mountains, hills and plains below 500M. Suitable for an average annual temperature of 15-23 °C, the absolute minimum temperature is less than -17 °C. Mostly distributed in the middle, the lower part of the plains, mountains and hilly slopes, slopes. In the neutral to slightly acidic soil and water loss in the red soil hilly areas, and the poorly drained sand and clay soils with iron-nodular layers below 50-60 cm in topsoil all grow well, especially at the edge of the low-lying swamp. The wetland pine is also more tolerant to drought and can thrive in the dry and barren lowland. It can also grow on fixed sand and peat soils where the shore is not very drained. Pine roots must have mycorrhizal fungi and their lives. Wind resistance is also strong.
III. Stand Growth Process Model
Fourth, nursery
1, picking
When selecting seeds, twigs should be selected (smooth tree trunks, small sharpness, narrow branching angles, and narrow crowns) 12-20 year-old healthy trees without pests and diseases. The cones can be changed from green to full brown between the “equinox†and “cold dewâ€. When the scales are not cracked, the cones are collected, and the threshing is carried out (the rate of seeding is 3-4%), and the collected seeds are put into bags. Store in a dry and ventilated place. The seeds weigh about 33 grams, 28,000-32,000 seeds per kilogram of pure seeds. The general storage period of seeds is 6 months. If the dried seeds are sealed in plastic bags, they can be stored at a low temperature of 0-5°C for 2-3 years.
2, nursery
Choose fertile, moist, loose sandy loam soil and loam soil as a nursery site. After the basal fertilizer was applied, the bed was built and the land was intensively smashed and smashed into pieces to flatten the bed. The sowing season is from early February to mid-March. Seeds were soaked with 2% formalin solution or Bordeaux mixture for 20 minutes before sowing and then soaked in warm water at 55-60°C for 18-24 hours. Seedlings are sown and seeded, with a distance of 10-20 cm and a fine layer of soil is laid in the sowing ditch. 20 kg of seeds per acre. After the seeds are sown, they should be covered with thin soil and can be covered with coke plaster. It is advisable to still see some of the seeds, and then cover the grass.
After sowing, most of the seedlings were unearthed and the cover grass was removed. Within 40 days after seedling emergence, special care should be taken to keep the seedbed moist. Fertilizers may be applied 1-2 times per month from the beginning of May to July, and ammonium sulfate 2-5 kg ​​will be applied per acre.
Container nursery and cutting seedlings can also be used.
V. Afforestation Technology
Afforestation can be carried out from mid-to late December to mid-to-late February. Container seedlings or 1-year-old bare-rooted seedlings are mainly used for afforestation.
(1) Afforestation density: 111-222 plants/mu. Plant spacing 2*2～2*3M. A seedling height above 70CM, ground diameter 0.5CM or more.
(2) Site preparation: The block preparation is not less than 5050cm, and the depth is not less than 20cm. The diameter of planted hole is not less than 30cm and the depth is not less than 30cm. The site preparation requires the topsoil to turn downwards, digging holes require the soil to be backfilled, and the topsoil be returned.
Six, tending management
(1) Annual management: Planting tending for 2 or more times in the year, only mow, not loose soil. Seedlings are upright and proper soil is used. In the 2nd and 3rd year, it tends to be raised 1-2 times a year, and if it hasn't closed yet in the 4th year, it will continue to raise 1 time. Plant breeding area should be expanded year by year. Pesticides should not damage plants and roots, and the depth of loose soil should be shallow, no more than 10cm. Pruning: The 5-10 year old wet pine canopy should account for 3/4-2/3 of the tree height. After 10 years of age, the canopy accounts for about 1/2 of the tree height.
(2) Thinning period: Thinning can be performed when the canopy density is above 0.9 and the pressed tree accounts for 20-30% of the total number of trees. The initial period of thinning is generally not more than 10 years. Using the thinning method of thinning in the lower layer, the first thinning intensity is 25-35% of the total number of trees in the stands, followed by 20-30%. After the first thinning, the canopy density of stands is not less than 0.7, and the interval between thinnings is not less than 5 years.
(3) The final cutting period: the fast-growing and high-yield forest is 20 years, and the forest is generally divided into about 25 years.
VII. Prevention and control of major diseases and pests
A, pine needles and brown spot, is a devastating disease. It can spray 1% equivalent Bordeaux mixture every 15 days for susceptible pine forests from April to June, mid-August to mid-September, and 75. % chlorothalonil 500-600 times or 25% carbendazim WP 500 times for artificial control. B. Masson's pine caterpillar. C, pine tip shoots and pine tip leaf roller moth. D, pine wood nematode and pine plant garden.
VIII. Engineering Afforestation Construction Design Table
Site preparation (units per acre): 2 (planting density 133 per acre, the same below).
Planting capacity (unit work / mu): 1.
Young forest tending (work per acre): Young tending in the year 1, Young forest tending in the next year 1, Young forest in the third year of tending 2.
main reference
1. Jiang Miaoding, Gao Zhihui, et al.: Research on the construction technology of wetland pine on the coastal rocky coast of the subtropical region. Zhejiang Forestry Science and Technology, 1996, 16 (3): 1-6.
2. Pan Zhigang and You Yingtian: Breeding of wetland pine, Loblolly pine and Caribbean pine. Beijing Science and Technology Press, October 1991, Beijing.
3. Guo Huairang, Peng Qingguang, etc.: Afforestation Technical Regulations (GB/T 15776-1995). China Standard Press, June 1996, Beijing.
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