RPA Assessment
As required by the Forest and Rangeland Renewable Resources Planning Act of 1974, the Forest Service makes a periodic (every 10 years) national assessment of United States forest resources. The latest Resources Planning Act (RPA) assessment published in 2010 shows that over the last 50 years, the inventory of hardwoods standing in U.S. forests has more than doubled as harvesting levels have remained well below the level of growth (Table 1).
Table 1: Changes in U.S. hardwood inventory 1953-2006 (Million m3)
| 1953 | 1976 | 1986 | 1996 | 2006 | |
| Inventory | 5213 | 7535 | 8894 | 9962 | 11408 |
| Growth | 210 | 247 | 320 | 349 | 420 |
| Mortality | 35 | 46 | 53 | 76 | 94 |
| Net Annual Growth | 175 | 201 | 267 | 273 | 326 |
| Harvested Volume | 116 | 119 | 142 | 169 | 161 |
| Excess growth over harvest | 59 | 82 | 125 | 104 | 165 |
Source: 2010 RPA Assessment
Between 1953 and 2007, the volume of U.S. hardwood growing stock increased from 5,210 million m3 to 11,408 million m3. U.S. Forest Service forecasts indicate that further increases of 15 to 20 percent are expected in the hardwood growing stock inventory through 2030. Projections of hardwood growth and removals nationwide indicate that growth will continue to exceed removals through to 2050. This rate of growth is being achieved despite high levels of domestic hardwood consumption in the U.S. and the achievement of record levels of hardwood exports.
The 2010 RPA Assessment demonstrates that the area of hardwood and mixed hardwood/softwood timberlands increased by 20% between 1953 and 2007 (Table 2). In 2007, 91% of the area of stocked hardwood and mixed forests was in the eastern States, and 9% in the western States.
Table 2: Stocked timberland area by major forest type group (Million hectares)
| Year | Hardwood & mixed forest types | Softwood forest types | Total stocked timberland |
| 2007 | 120 | 84 | 205 |
| 1997 | 117 | 86 | 202 |
| 1987 | 108 | 86 | 195 |
| 1977 | 107 | 88 | 195 |
| 1953 | 99 | 101 | 200 |
Source: 2010 RPA Assessment
Considering forest values other than timber production such as biodiversity protection and provision of social services, the 2010 RPA Assessment reports that regulations governing these forest values have been increasing overall. Some 44 States now have best management practice legislation intended to promote better management of lands, especially when timber production is involved and particularly to protect water quality. The 2010 RPA Assessment also indicates that overall hardwood forests are getting older in the United States and that this maturation is leading to increased eco-system diversity.