Rothrock.] 114: [March 2, 



Forests of Pennsyhania. 



By J. T. Rothrock, Botanist Member of the Pennsylvania Forestry 

 Commission. 



(Read hefore the Americati Philosophical Society, March 2, IS94.) 



Exact statistics as to the forest area are as j'et not available for the 

 State of Pennsylvania. It is true that we can speak with some certainty 

 of the area of our State which is devoted to farming interests. Deduct- 

 ing this from the known area of the State would, however, still leave us very 

 wide of an exact statement as to the area actually covered by a growth 

 of wood wliicli is now, or ever will be, productive forest land. There 

 would remain unaccounted for the space covered by cities, towns and 

 villages ; by miaes, where the surflice is allowed to remain unutilized 

 because the wealth below dwarfs its importance, and because the sur- 

 roundings are not favorable to production of trees ; and lastly there 

 would remain the fact that an enormous percentage of the reputed wood- 

 land is now producing timber of the slowest growing and least valuable 

 kinds of wood, if indeed it should be designated as wood at all. It will 

 be, however, an approximate statement, based upon the reports of oiir 

 assessors for the year 1892, to say that we have accounted for 16,359,387 

 acres of cleared land, and 9,159,826 acres of woodland. This will at 

 least fairly represent farming land, and the area covered by woody growtli 

 of some kind, and may afford a basis for computation as to the condition 

 of things which should exist. By the above statistics we may account 

 for about 25,555,500 acres of farm and woodland. This, however, leaves 

 from four to six millions of acres of our State area to be accounted for as 

 coming neither under farming nor forest conditions at present. Nomi- 

 nally we have nearly 36 per cent, of our area in trees, if we accept our 

 assessors' statements as a basis of calculation. 



For convenience sake this j^aper will be divided thus : 



I. The Kinds of Timber-producing Trees in Pennsylvania. 

 II. Most Important Timber-producing Areas in Pennsylvania. 



III. Configuration of the State in Relation to Growth of Timber. 



IV. Rates of Growth of Most Important Kinds of Timber. 

 V. Obstacles to the Growth of Timber. 



(a) Natural Obstacles. 

 (6) Obstacles due to Human Agencies. 

 VI. Relation of the Commonwealth to Forest Restoration. 

 VII. Methods of Forest Restoration. 



I. The Kinds op Timber-producing Trees in Pennsylvania. 



The list of such trees indigenous to our State, which are of sufficient 

 size, or in sufficient abundance to be of commercial importance, numbers 

 seventy-eight species and is as follows : 



