Resources of the white birch (Betula platyphylla) for sap production and its ecological characteristics in northeast China
2001
Shi, F. (Northeast Forestry Univ., Harbin (China)) | Li, J. | Koike, T. | Nie, S.
In northeast China, birch species form dominant tree flora with eleven species of the genus Betula, including trees and shrubs have been recorded. Most of the birch species invade after disturbances, such as harvesting of conifers and forest fires, and grow as a pioneer species. Recently, practices of non-destructive forest management have been examined for natural resources preservation. Rich birch forests, especially white birch (Betula platyphylla) in northeast China are regarded as an important resource for sap production. Based on phenological observations, the sap of white birch starts to exude from early April in the Zhangguangcai Mountains, northeast China. The optimal period for tapping sap in white birch was from early of April to mid-May. The tree age for producing tree sap in white birch is considered to be from 45 years old and the DBH (diameter of breast height) is above 16 cm. For resource conservation, a method for accelerating the natural regeneration of white birch is discussed in relation to its biological characteristics.
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