The Forests of Economic Value Institute under the Academy of Forest Science is one of the leading scientific research units contributing greatly to the forest restoration campaign now underway across the DPRK.
Established in the 1960s, it has more than 10 labs including those of oil-bearing trees and medicinal plants, a large greenhouse and several-hectare tree sapling fields. And it has over ten scientific research forests in different parts of the country.
The institute has mainly been engaged in the development of wild-fruit tree varieties with good taste and high quality and productivity that are suitable for the climatic and soil conditions of the country, the preservation of their characteristics and the spread of them.
In the course of this, its researchers succeeded in growing saplings of high-yielding trees and perfecting the methods of producing saplings of major tree species of economic value including grafting like seed sprout grafting and cleft grafting for pine-nut trees and the planting of cuttings of seabuckthorn trees, thus creating a large area of forests of chestnut, pine-nut, Korean evodia and seabuckthorn trees in different parts of the country.
“We have bred 15 national forest plant varieties such as high-yielding chestnut, seabuckthorn, walnut and white pine-nut trees in the period of the fifth five-year plan for scientific and technological development that started in 2016. Several of them were awarded certificates of registration of sci-tech achievements and introduction of state sci-tech hits,” said director Ri Hyon Song.
He added that a technology of tissue culture for saplings was completed in the period.
Since the country has been bustling with afforestation, the demand for tree saplings of high economic value is on a steady rise.
Such ordinary vegetative propagation methods as grafting and cutting planting are insufficient to meet the needs.
Therefore, the institute laid foundations for annually producing one million saplings through tissue culture this year.
At present the tissue culture lab is conducting inoculation for multiplication of such trees as Actinidia arguta, Zizythus jujuba, Crataegus pinnatifida, Corylus heterophylla and Cerasus humiis (Bge) Sok.
Progress in study of native trees
Chestnut and pine-nut trees are indigenous species of Korea.
Chestnut is very familiar with the Koreans as it always reminds them of the mouthwatering roast fruit and makes them hum the tune of Roast Chestnut Ballad.
The scientists developed a method of boosting the production of high-yielding chestnut trees to open up a prospect of covering all the chestnut forests of the country with them in the near future.
“Two to three years were required for producing high-yielding chestnut saplings in the past. But the development of the method of doing a graft directly to seed sprouts has made it possible to reduce the sapling production cycle to a year and increase the land utilization rate and sapling output 2.5 and 4 times respectively,” said deputy director Kil Myong Chol.
The method has been introduced into forests in such areas as Unjon County of North Phyongan Province to replace native chestnut trees with the high-yielding variety, and it saves much labour and will bring benefits in the near future, Kil added.
“In general, a pine-nut tree bears fruits 15 years after it is planted. That’s why people say the tree is planted for the coming generations, I think. But this new variety begins to produce fruit five years after,” said researcher Ri Myong Chol.
The institute established a technology of producing pine-nut saplings based on a new grafting method to ensure they bear fruits five years after planting and increase output two to three times.
A bonsai lab was set up in the institute this year.
“Tray planting is an art. You can succeed in this study only when you love trees and develop the ability to interact with them,” said the lab chief Kim In Sop.
According to him, the Koreans have a long history of tray planting.
He added that pot trees and shrubs and tray landscapes on different themes that are cultivated and created by applying plastic arts have been presented to national flower exhibitions in recent years.
The lab is now busy with securing the seeds of trees and shrubs fit for tray planting including the pine tree naturally growing in alpine regions. It is also engaged in developing a grafting method for giving shapes to trees, a method of making flowers open and bear fruits at desired time by controlling growing points and growth, a method of determining the size, shape and colour suitable for pots.
The researchers are striving to present new products in the period of the sixth five-year plan for sci-tech development.
Over 100 hectares of seabuckthorn forests were planted in the Unhung area of Ryanggang Province.
The trees laden with yellow, yellowish brown and other colour fruits add beauty to the scenery of the area and serve as an asset for its economic development.
The forests are also associated with the painstaking efforts of the scientists of the institute.
As all parts of the tree, from the leaf to root, are rich in various medicinal and nutritional components, seabuckthorn is called the king of wild fruits.
The researchers completed a method of mass-producing the saplings of the tree of good breed which grows well even in the alpine regions with a considerable variation in temperature between day and night. They also expounded its biological features and fruit productivity according to soil composition in northern areas, and several varieties of it have been inscribed on the list of national forest plants.
“Active support of overseas compatriots was a great help to our success,” said Kim Un Ho, PhD.
Overseas compatriots donated saplings of high-yielding seabuckthorn variety and essential materials for its study, he noted.
The institute is working to achieve the target of planting some 1 000-hectare forests of seabuckthorn trees in northern highlands including Ryanggang Province during the second stage of the forest restoration campaign.
In addition, it established a technology of breeding and cultivating aronia, walnut, Korean evodia and other trees of good breed and an agroforestry technology for major tree species of economic value.
It also developed a technology of double and triple cultivation of tree saplings in containers to increase sapling production over five to seven times more than previously and root protective agents, growth stimulants and nutrient solutions for trees as well.
The pyroligneous acid it developed with forest by-products is regarded as a promising soil disinfectant and vegetable nutrient.
The institute is making preparations for setting up raw materials bases for bioindustry from next year in order to build more forests of economic value as early as possible.