树皮年轮的研究及其意义

A Study of Annual Rings in Tree Bark and Their Significance

在对38科54属96种药用及常见经济树种进行实验研究的基础上,以树皮横切面所见纤维束环带为指标,阐述了树皮年轮的客观存在.并对依据树皮年轮鉴定树龄在林学和生药学等方面的实际应用进行了探讨.

The age of a tree is usually estimated by counting the annual rings of the xylem. However, this is not appropriate for the determination of the age of uncut trees. Based on observations of bark samples collected from trees belonging to 96 species of 38 families, of different ages, and growing in different places and seasons, the following conclusions were drawn, (1) Annual rings could be found in the bark of most trees. The number of layer of fibre bundles in the phloem produced by the cambium corresponds to the number of annual rings in the xylem. This phenomenon has been found in trunk,branch and root barks, as well as in the trunk bark. Annual rings occur both in young and old bark. (2) Since the quality of crude drugs from bark origins sometimes needs to be evaluated in terms of the tree ages,bark rings might be used as a reference. The present study also provides a new means for age determination of ancient trees