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Timber Inventory Trends Growing stock |
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Timber Inventory Trends Growing stock |
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Because of the substantial positive difference between net growth and removals of hardwoods in the East, hardwood growing stock and sawtimber inventories have been increasing steadily for over 50 years. In both regions, additions to inventory are slowing as removals increase and as hardwood stands increase in average age. The same trend can be seen in hardwood growing stock inventory data for the nation as a whole.
Changes in Hardwood Growing Stock Volumes in the Eastern United States, 1964-1997
Million cubic feet |
1964 |
1977 |
1987 |
1997 |
S. Central |
51,987 |
61,474 |
70,874 |
80,392 |
Southeast |
46,998 |
60,691 |
68,154 |
71,124 |
N. Central |
41,792 |
51,838 |
61,896 |
74,640 |
Northeast |
52,835 |
67,320 |
80,524 |
90,234 |
Source: Luppold, et al., 2002.
Table 8
Changes in Hardwood Sawtimber Volumes in the Eastern United States, 1964-1997
Million cubic feet |
1964 |
1977 |
1987 |
1997 |
S. Central |
133,625 |
160,163 |
193,571 |
247,628 |
Southeast |
126,981 |
163,703 |
199,504 |
216,997 |
N. Central |
98,112 |
128,138 |
161,883 |
203,370 |
Northeast |
92,851 |
116,577 |
170,582 |
229,502 |
Source: Luppold, et al., 2002.
As shown in Figure 22, the increase in growing stock inventory has occurred across all diameter classes.
Figure 22
Distribution of Hardwood Growing Stock on
Timberland by Diameter Class, 1953, 1977, and 2002
Midpoint Diameter Class (inches)
Source: Smith et al., 2004.
When hardwood growing stock inventory is examined by ownership, a pattern of rising growing stock volume can be seen for all categories of ownership except for forest industry (Figure 23). Over 70 percent of hardwood growing stock is controlled by nonindustrial private forestland owners.
Figure 23
U.S. Hardwood Growing Stock on
Timberland by Ownership, 1953-2002
2002 1997 1987 1977 1953 |
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National Forest Other Public Forest Industry Non-Ind. Private |
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0 100 200 300 400
Source: Smith et al., Forest Resources of the United States, 2002. USDA-Forest Service, 2004.
As noted earlier, hardwood forestland nationwide is beginning to change such that the extent of forests dominated by pioneer species is decreasing, while the extent of forests dominated by species representing secondary or subsequent levels of succession is increasing. This effect is not yet evident, however, in hardwood growing stock data for the eastern U.S. (Figures 24-27); increases have occurred over the past four decades in all species groups except yellow birch and tupelo/black gum. The greatest percentage increases have occurred in the maples and in yellow poplar.
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