19 



This improvement work is mainly directed toward the correction of 

 bad conditions, as stated in the types above, and may be said to con- 

 sist of three operations, improvement cuttings, thinnings, and planta- 

 tion work. 



There is a distinction to be made between improvement cuttings and 

 thinnings. 



An improvement cutting is the first cutting made on a new area, 

 with the purpose of bringing the growing stock as near the normal 

 as possible, by removing dead, dying, and valueless species. A thinning 

 is one of the cuttings made at regular intervals during a rotation, to 

 reduce the growing stock to the normal. This distinction is used by 

 the Federal Forest Service, and has been sanctioned by various au- 

 thorities. 



While our systems of protection embrace all of the lands we own, 

 our improvement work is directed mainly towards the lands of types 

 C and F, the over-stocked areas, and the open fields. In one case, on 

 the Mont Alto Division of the South Mountain reserve, a tract which 

 came under type A has been improved, but this is the only one of that 

 class. 



All of our lands demand more or less immediate attention, and I 

 shall attempt to show why this attention should be given them ; that 

 is, show the necessity for advancing improvement work on the re- 

 serves. 



First, we will consider it from the point of silvicultural reason. 

 This reason applies more closely to lands of the over-stocked type 

 than to any of the others. On these areas we find conditions which 

 are the very reverse of good. The trees are crowded together, their 

 boles are thin and spindly, and their crowns small and sparse. 



Every quality of soil has a definite amount of nourishment available 

 for plant use, and no more. Consequently when an area contains 

 more trees than the soil contains nourishment to sustain, we find the 

 conditions stated above. And this is what we find on lands of type C. 

 There is insufficient nourishment for the stock, consequently the trees 

 are retarded in their development and what growth there is, is gen- 

 erally of an inferior quality. These conditions are opposed to the 

 best silvicultural development standards, and the longer -they are 

 allowed to remain so, the worse they will become. Now, go in there, 

 remove the smaller and less valuable trees, and make available for 

 the remaining stock the food which the removed trees used, and also 

 the space for the spreading of their crowns. The remaining stock 

 will advance rapidly, their crowns will spread out, and the diameter 

 and height increment will increase. If enough trees are removed, the 

 boles of the small spindly trees will increase more rapidly in diameter. 

 If carrying out this improvement work means the advantages here 



