

ESTIMATING STANDING TIMBER. i iet | 
“ 
are calipered. : Small trees are measured principally in studying 
the question of future growth. 
The advantage of the strip method is that it gives an excellent 
average of the whole area, because the strips are run through the 
open as well as the dense portions of the forest. Where square 
surveys are used the cruiser is often tempted to locate them only 
in the best portions of the forest. 
‘On large tracts satisfactory estimates can be made by the meas- 
urement of about one out of every 30 acres. In very extensive 
forest tracts the Bureau of Forestry usually measures not more 
than one or two out of every hundred acres. 
Great care must be taken to lay off the sample strips in such 
a way that they will represent the average conditions in the 
forest. On mountain slopes the strips should be run vertically or 
diagonally up and down the slopes, and not horizontally around 
them, because the character of the forest is usually different at 
different elevations. 
Where the country is divided into square townships a good 
method is to run sample strips straight across each township at 
stated distances apart. One side of the township is first traversed 
by the cruiser, who locates the points where he wishes the sample 
strips to begin. The calipering crew then measures strips, begin- 
ning at these points and running across the township in a stated 
compass direction. Plate I shows the manner in which the strips 
were located by the Bureau of Forestry in making a forest work- 
ing plan for a township in the Adirondack Mountains. 
For convenience in measuring sample acres a tally sheet has 
been devised which is easily used in the woods and which is of 
great value in working up the results. A sample tally sheet has 
been filled in with the figures of an actual valuation survey. 


