Table 6.  Volume of growing stock on timberland by forest-type group and  
                 softwood/hardwood species categories, Pennsylvania, 2002 
  
                     (Standard error as percentage of total) 
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                                     Species group                              
     Forest-type           ________________________________          Total       
         group                  Softwoods         Hardwoods       all species   
   ___________________________________________________________________________ 
   White/red pine                    13.9              17.2              13.4  
   Spruce/fir                        41.2              70.5              40.6  
   Loblolly/shortleaf                31.9              34.9              30.6  
   Oak/pine                          27.6              27.1              26.4  
   Oak/hickory                       10.0               3.3               3.3  
   Elm/ash/red maple                 43.6              14.2              14.1  
   Northern hardwoods                 8.5               3.7               3.7  
   Aspen/birch                       36.0              22.4              21.6  
                           ___________________________________________________ 
   Total, all groups                  6.2               1.8               1.7  
   ___________________________________________________________________________