上海主要古树树干腐烂状况检测研究

Study on the Health Status of Typical Aged Trees in Shanghai City

应用声纳无损探测仪,检测了上海地区100余株主要古树树种的树干内部腐烂状况,检测中形成3种内部截面腐烂状况类型,即空洞、腐烂、疏松,每种类型具有一定的面积,相应为S1、S2、S3,截面总面积计为S,3种类型的截面面积总和在截面总面积的百分比为R。通过图像分析,得出如下结论:同种古树随着树龄的增长,其腐烂程度逐步加大;4种树龄相同的古树,其腐烂程度不同,悬铃木最易腐烂,广玉兰、香樟其次,银杏的腐烂程度最轻;根据R的大小,将古树的健康状况分为5个等级,即一级(0%≤R≤5%)、二级(5%<R≤15%)、三级(15%<R≤30%)、四级(30%<R≤50%)、五级(50%<R≤100%)。

Sonar non-destructive detector was applied to detect the internal rotten conditions of more than 100 aged trees in Shanghai City. Three kinds of rotten sections were found： hollow, rotten and loose. Each kind has a certain area indicated respectively by S1 , S2 and $3, and the total section area is S,and ratio of the total area of these 3 kinds of rotten sections to the total area of all sections is R. Image analysis shows that the aging of trees leads to aggravated rot ; 4 different species of the same age have different rotten conditions, Platanus acerifolia （ Ait. ） Willd. is the most vulnerable one to rot, followed by Magnolia grandiflora Linn. and Cinnamomum camphora （ L. ） Presl. , and Ginkgo biloba L. has the best conditions. According to the value of R, health status of the aged trees was categorized into 5 grades, Grade Ⅰ（0% ≤R≤ 5% ）, Grade Ⅱ （5% 〈R≤15%）, Grade Ⅲ（15% 〈R≤30%）, Grade Ⅳ （0% 〈R≤ 50%）, Grade Ⅴ（50% 〈R≤100%）.