i8 GEOLOGICAL SURVEY OF NEW JERSEY. 



sections containing less than 10 acres of forest in 100 acres 

 of upland are not, as might at first be supposed, in the most 

 populous regions, but in the agricultural sections, viz., the 

 Raritan valley, in Somerset and Hunterdon counties, and thence 

 southward in a belt about 12 miles wide along the Delaware 

 river, in Mercer, Burlington, Camden, Gloucester and Salem 

 counties. Other deforested areas are the Musconetcong, Pohat- 

 cong and Delaware valleys, in Warren county, and about the 

 Navesink and Shrewsbury rivers, in Monmouth county. 



CHANGES IN FOREST AREA. 



A period of from 12 to 20 years has elapsed since the original 

 topographic survey of the State was made. Since that survey 

 gave the area of forest it has been possible to compare present 

 conditions with those of 16 years ago. This comparison shows 

 that the amount of forest which has been cut off and cleared up 

 for cultivation in northern New Jersey is very insignificant, and 

 is offset by the clearings which have been abandoned and allowed 

 to grow up. Taking the State as a whole, there is nearly as 

 much forest to-day as there was in 1860. In this connection the 

 following data from the United States census are instructive : 



Total land in farms, l8 5- '860. 1870. 1880. 1890. 



acres 2752,946 2983,525 2,989,511 2,929,773 2,662009 



Improved land in 



farms, 1,767991 1,942,281 1,978,067 2,097,719 1,999,117 



These figures show practically no increase in the land under 

 cultivation since 1860, and a decrease of 320,000 acres in unim- 

 proved land in farms. 



Analyzing the changes in forest area, we find that there was 

 progressive deforestation in all portions of the State up to 1860, 

 although the rate was most rapid from about 1830 to 1850, and 

 very slow in many counties after the latter date. Monmouth, 

 Mercer, and all counties farther north excepting Sussex, show 

 stationary forest area after 1860. There has been some clearing in 

 the Kittatinny and Delaware valleys, in Sussex county, since 1860, 

 amounting to 27,000 acres, or about one-fifth of the forest area. 

 In all of the other northern counties the new clearing has not 



