14 



NEW HAMPSHIRE EXPERIMENT STATION [Bulletin 255 



frequent and paper birch, hop hornbeam and lesser species scattered 

 in occasionally. 



Few hardwood stands grow to more than 25-30 years of age, as they 

 are then about the right size to cut for cordwood. Any older stands 

 are probably cut selectively, as wood is needed. 



Fig. 3. A typical even-aged gray birch stand, classified as G. B. 20-1. 



While there are few pure stands of any species of hardwoods, except 

 gray birch, the important insects and fungi are not particular, and 

 attack several species alike. The gypsy moth, Porthetria dispar, is the 

 worst offender, choosing cherry, oak, maple and birch as its favorites, 

 but accepting even softwoods, though the young larvae cannot eat soft- 

 wood needles. Ash and hickory are the only hardwoods not damaged. 



The rots, which do the most damage of the fungi, also disregard 

 species. Forties igniarius, which forms the common shelf fungi on oaks, 

 maples, poplar, birch, beech, hickory, willow and others, causes the 

 common brown heart rot which is the most widespread disease of hard- 

 woods. 



Swamp. The swamp type, covering only about one square mile 

 altogether, is the last one to discuss. Setting aside the few ponds, the 

 swamps were either covered with bunch grass and perhaps an occa- 

 sional elm, or with alder. The grass swamps may often be pastured, 

 as the bottoms are clay and bog holes are not reported. There is so 

 much other land available that this is only incidental. The alder 

 swamps are of no value at present. Salt marshes along the bay and 

 tidewaters of the Oyster River are covered with grass suitable for 



