ft 9f-9 



/^^i^^ United States 

 Department of 

 Agriculture 



Forest Service 



^^7^ Northeastern Forest 

 ^ Experiment Station 



Research Note 

 NE-322 



1984 



Predicting Diameter at Breast 

 Height from Stump Diameters for 

 Northeastern Tree Species 



Eric H. Wharton 



;-(ECORD; 



Abstract 



Presents equations to predict dianneter at breast height 

 fronn stump diameter measurements for 17 northeastern tree 

 species. Simple linear regression was used to develop the equa- 

 tions. Application of the equations is discussed. 



ODC 521.27 



Either standard or local volume 

 tables are used to assess volume loss 

 of trees. Standard tables provide an 

 estimate of volume usually based on 

 d.b.h. (diameter at breast height) 

 measurements and some measure of 

 height. Local volume tables provide 

 an estimate of volume based on d.b.h. 

 measurements alone. Use of either 

 table requires some measure of d.b.h. 



However, many situations arise 

 today where the volume, and ulti- 

 mately the value of trees, must be 

 assessed from stump measurements. 

 These situations include assessing 

 timber sales based on stump diam- 

 eters, checking harvesting practices 

 following tree removals, tracing the 

 history of cutover lands, assessing 

 damage resulting from adverse en- 

 vironmental conditions, and deter- 

 mining volume loss due to timber 

 trespass (Hampf 1954). In all of these 

 situations, only the stump diameter is 

 known. Therefore, in order to use 

 volume tables, d.b.h. must be esti- 

 mated from stump measurements. 

 The relationship between stump 

 diameter and d.b.h. is usually highly 

 correlated since the variable to be 

 estimated is only AVi feet up tne tree 



bole from the known variable, stump 

 diameter. Once d.b.h. is estimated, 

 the tree volume can be estimated. 



Previous studies relating stump 

 diameter to d.b.h. have been made. 

 McClure (1968) and Raile (1978) made 

 two of the most recent studies in the 

 Southeastern and North-central re- 

 gions of the United States, respec- 

 tively. In the Northeast, Hampf (1954; 

 1955a, b, c, d, e; 1957a, b) published 

 stump diameter/d.b.h. relationships 

 for white pine, American beech, north- 

 ern red oak, sugar maple, yellow birch, 

 yellow-poplar, pitch pine, and white 

 oak. Since the 1950's, additional re- 

 search in the Northeast has been 

 limited to a single estimator of several 

 northern hardwood species grouped 

 together (Nyland 1977). 



The relationships between stump 

 diameter and d.b.h. should not change 

 miuch over time, but there has been 

 some recent interest in using them 

 for a wider range of species, espe- 

 cially the high-value species. For this 

 reason, I have developed equations 

 that predict d.b.h. based on stump 

 diameter for 17 of the major north- 

 eastern tree species. 



Data Collection 



The data were taken from utiliza- 

 tion plots in 14 northeastern states 

 (Connecticut, Delaware, Kentucky, 

 Maine, Maryland, Massachusetts, New 

 Hampshire, New Jersey, New York, 

 Ohio, Pennsylvania, Rhode Island, 

 Vermont, and West Virginia). The 

 plots are used to relate timber volume 

 output to timber inventory at private 

 logging operations. Between 1969 

 and 1979, more than 7,000 trees were 

 measured. 



Tree species, stump diameter, 

 and d.b.h. measurements were ob- 

 tained for all trees on the utilization 

 plots. Diameter at breast height was 

 taken 4V2 feet above the ground on 

 the uphill side with a diameter tape, 

 and measured to the nearest 0.1 inch. 

 After the tree was harvested, stump 

 diameter inside the bark was taken 

 across the axis of the butt log on 

 cylindrical logs, or averaged across 

 the largest and smallest diameters 

 on irregularly shaped logs. Stump 

 diameter was measured to the nearest 

 0.1 inch and ranged from 2.1 inches 

 to 48.5 inches (Table 1). No stump 

 heights were measured. 



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