136 REPORT OF THE No. ^ 



Secondly, to prepare a supplemented and improved map of the physiographic 

 features. 



Thirdly, to secure an estimate of the available pulpwood and timber resources. 



Fourthly, to make general studies in immature stands to obtain an idea of 

 their potential value. 



Method. 



Methods used in previous years were again employed to satisfy the object 

 of the survey. The organization consisted in aerial sketching work in conjunction 

 with field parties. 



Aerial Sketching. — Work was carried on from two air bases, one at Eva lake 

 south of Kawene on the Canadian National Railway, and the other at Fort 

 Frances. Maps were prepared by direct sketching from the air, showing the 

 existing waterways improved, plus any additional lakes and streams. With 

 the waterways mapped more completely, sketching of forest types proceeded. 

 Finally as the sections of the country were sketched these maps were turned 

 over to the field parties. 



Ground Work. — Strips were used to obtain samples for the estimate and 

 check type boundaries. For most of the area strips were run at half-mile 

 intervals, but in the better pine stands this distance was reduced to one-quarter 

 mile. The width of strip also varied from eleven feet to sixty-six feet according 

 to the class of timber and the density of the stand. 



Strips thirty-three feet wide were run in selected young and second-growth 

 stands and all trees were tallied. This supplied complete composition for the 

 stand. Plots were then laid out and a growth analysis made on trees represent- 

 ing each diameter class. 



As the plots were taken in representative stands from young growth to 

 maturity the changes in composition and growth could be recorded. 



General Forest Conditions. 



Three type conditions were recognized by composition, namely, coniferous 

 stands having less than 20 per cent, of the species hardwoods; mixed stands 

 having 20-80 per cent, hardwoods; and hardwood stands having less than 

 20 per cent, of the species conifers. A further division of the type was made on 

 the basis of age or maturity. Types were mapped as mature, second growth, 

 or young growth. A mature stand is one now containing close to its maximum 

 yield and is ready to be cut. Second-growth stands are more confusing to define. 

 Where a stand of timber has originated after a fire — is now from 40-60 years old 

 and the average diameter of the trees is 6"-7" for jack pine and 4"-5" for spruce 

 the stand has been classed as second growth. Recently as a result of growth 

 studies made for jack pine and spruce, a second growth-stand is one which if 

 allowed to grow can reasonably be expected to double its value in another 

 twenty years. Young growth stands represent a more immature growth, usually 

 the growth from 15-40 years after a fire. Trees are from l"-4" in diameter, so 

 that the whole stand does not carry trees of commercial sizes. 



Since so much of the surveyed area has been classified as "recent burn" 

 this term deserves definition. After an area has been burned over there is a 

 period, lasting up to fifteen years, during which the new growth does not express 

 what the future composition might be. Consequently until such areas can be 



