lUSDA FOREST SERVICE RESEARCH NOTE NE-107 



1969 



N 



ortheasfern Forest 







(REST SER^ 





S TA^^^^^^^^^^^^Q py 



t\ PA. 





X periment Station 



mm 









BARK THICKNESS RELATED TO TREE DIAMETER 

 IN SUGAR MAPLE (ACER SACCHARUM MARSH.) 



Abstract. — Bark thickness for sugar maple trees in Vermont was 

 found to be related to tree diameter at breast height (d.b.h.). 

 The relationship was positive — as the diameter increased, the 

 bark thickness increased. 



Foresters using outside bark diameters to determine forest tree param- 

 eters should be aware that bark thickness not only varies by stem size and 

 individual species, but also by site quality and tree age {2)} 



The majority of published material shows bark thickness to be a linear 

 function of tree diameter at breast height (d.b.h.). In conifers, Johnson 

 (i) found this to be true with Douglas-fir {Pseudotsuga taxifolia (Poir.) 

 Britt.) while Ostlin (3) reported that, in birch (Betula Sp.) and asso- 

 ciated conifers, bark thickness increased from better to poorer sites and 

 also increased with tree diameter and age class. However, no information 

 has been available concerning the relationship of bark thickness to d.b.h. 

 for sugar maple. 



In 1967 our Sugar Maple Sap Production project at Burlington, Ver- 

 mont, conducted a study to determine this relationship in sugar maple. 

 It was found that bark thickness of sugar maple trees in Vermont is 

 positively correlated with tree d.b.h.; that is, as d.b.h. increases, so does 

 bark thickness. 



Methods and Results 



Measurements were taken on a total of 209 trees ranging in d.b.h. from 

 5.0 to 39.0 inches. These trees were located on glaciated, medium quality 

 sites having slopes of 15 percent or 'less. 



^ Italic numbers in parentheses refer to Literature Cited, p. 4. 



1 



