SUMMARY
Paulownia is a marvelous tree species with its characteristics of fast-growing, good wood quality, multiple uses, wide-ranged distribution and easy propagation. It has also a unique biological character, i.e., its root system grows in deep earth and its crown develops in loose structure, which enable it suitable to be intercropped with crops or mixed planting with other shade-enduring trees. So, Paulownia is also a good tree for development of agroforestry. Recently, Paulownia-crop intercropping models have been applied and extended to an area of 15 million hectares in the central plains of North China, and the mixed planting models of Paulownia with other economic plants to an area of 20,000 hectares in the hilly areas of south China. As a result, the total number of Paulownia trees growing in China is as many as 1 billion including the Paulownia trees planted for agroforestry system and other purposes.
Paulownia grows fast biologically, the high-yielding plantation in 10 years old can grow its mean height to 16-20 m, its mean DBH to 35-40cm and its standing volume to 0.5 m3 per tree if the appropriate management is given. In addition, Paulownia wood has many special properties. As one of the lightest woods in China, Paulownia wood has the properties of high resistance to distortion and splitting, high resistance to insect, low coefficient of shrinking, moisture breaking, easy for drying, easy for processing, easy for sculpting, pretty in strains, without smell, and good at acoustics and insulation. Therefore, it is used as the roof purling or beam for building house in rural areas, and also is used for making furniture, window frame, door, furnishing board and handicraft. It is also good raw material for making music instrument. Besides, the Paulownia wood can also be used for industrial purposes, such as for making wooden model, packing board for air transportation, vehicle or ship board and plywood.
The development of Paulownia is supported by the successful research, more than 30 superior clones suitable for different climates were selected and bred, and gave impetus to the development of Paulownia in China along with the progress in Paulownia breeding. Besides, the great progress in cultivation technology, controlling pests and disease and wood processing and utilization has also been made. A series of techniques of nursery have been developed as root cutting, seeding and intercropping cuttage raising, the technique of artificial stem extension has been applied in production of Paulownia. With regards to pests and diseases, although the most effective measure has not been found to control Witches Broom and Giant Bagworm, some research results were applied to control Witches Broom and Giant Bagworm effectively. Recently, the oriented cultivation of Paulownia plantations is being paid attention due to industrial need. Now Chinese government is putting the protection of natural forests into effect, and thus the oriented cultivation plantations will be quickly developed to meet the demand of the economic construction in the coming years. On the other hand, many companies are also engaged in the development of Paulownia and are establishing the plantations for the good quality woods and quick supply of woods.
Besides, the sustainable development of Paulownia, which is being paid attention by researchers and farmers, is beneficial not only to the preservation of natural forests owing to sufficient supply of woods but to economic construction. At present, the long-term plan of Paulownia development is being drawn up to obtain the maximum economic results and ecological benefits. In the traditional cultivation areas the establishment of oriented plantations will be taken seriously to supply raw materials with the construction and wood-based panel on the one hand, and to develop the decorative board, super veneer and music instrument with high additional value on the other hand. While in the new cultivation areas the development of Paulownia is for the purpose of meeting the demand of farmers for woods and making the ecological benefit well. In the hilly areas of south China, the mixed stands of Paulownia with other species and four-sides planting should be encouraged. While Paulownia will be developed for the ecological and economic protection forests in the arid and semi-arid areas of northwest of China. |