Table 1. - Annual estimates, uncertainty, and change.

Figure 1. - Area of forest land and timberland by year.

Figure 2. - Area of forest land by size class and top six 

forest-type groups.

Pennsylvania’s Forest Resources, 2010 Research Note NRS-122

This publication provides an overview of forest resource attributes for Pennsylvania based on an annual inventory 

conducted by the Forest Inventory and Analysis (FIA) program at the Northern Research Station of the U.S. Forest 

Service. These annual estimates, along with web-posted core tables, will be updated annually. For more information 

please refer to page 4 of this report.

1

Note: When available, sampling errors/bars provided in figures 

and tables represent 68 percent confidence interval. 

Figure 3. – Area of timberland by stand size class and 

year.

Estimate 

(2010)

Sampling 

error (%)

Change(%) 

since 2005

Area (1,000 acres) 16,764 0.7 1.1

Number of live trees > 1-inch 

diameter (million trees) 8,237 1.7 -2.6

Dry biomass of live trees > 1-inch 

diameter (1,000 tons) 1,034,357 1.0 5.2

Net volume of live trees > 5-inch 

diameter (million ft3

) 36,205 1.1 5.7

Annual net growth of live trees > 

5-inch diameter (1,000 ft3

/year) 870,910 2.9 n/a

Annual mortality of live trees 

(1,000 ft3

/year) 336,175 3.9 n/a

Annual harvest removals of live 

trees (1,000 ft3

/year) 380,271 7.2 n/a

Annual other removals of live trees 

(1,000 ft3

/year) 24,384 31.7 n/a

Timberland Estimates

Area (1,000 acres) 16,216 0.8 1.2

Number of growing-stock trees > 

5-inch diameter (million trees) 8,025 1.7 -2.8

Dry Biomass of live trees > 

1-inch diameter (1,000 tons) 999,076 1.1 5.1

Net volume of live trees > 5-inch 

diameter (million ft3

) 34,961 1.2 5.6

Net volume of growing-stock trees 

(million ft3

) 32,460 1.2 3.8

Annual net growth of growingstock trees (1,000 ft3

/year) 762,870 2.9 n/a

Annual mortality of growing-stock 

trees (1,000 ft3

/year) 245,197 4.4 n/a

Annual harvest removals of 

growing-stock trees(1,000 ft3

/year) 322,137 7.3 n/a

Annual other removals of growingstock trees (1,000 ft3

/year) 52,533 24.9 n/a

Forest Land Estimates
Table 2. - Top 10 species by statewide volume estimates, 2010.

2 

Figure. 4. - Area of forest land by major owner group (2007) and size of family forest landholding (2006).

Private forest land - 70.8 percent of all forest land. 

Public forest land - 29.2 percent of all forest land. 

Other 

1 Red maple 6,742.1 2.6 6.6 16,325.4 3.8 14.6

2 Black cherry 3,825.2 4.1 7.5 12,126.1 5.4 10.4

3 Northern red oak 3,481.6 4 7.3 13,669.5 4.6 10.9

4 Sugar maple 2,625.3 4.9 4.5 7,754.2 6.1 12.0

5 Chestnut oak 2,547.2 4.3 2.0 6,852.5 5.1 8.5

6 Eastern hemlock 1,804.3 5.9 1.5 5,123.9 6.8 2.8

7 Yellow-poplar 1,709.7 7.6 17.4 7,310.4 8.6 24.2

8 White ash 1,697.7 5.1 3.7 5,179.5 6.8 4.6

9 White oak 1,632.2 5.3 -0.3 5,415.8 6.6 4.2

10 Sweet birch 1,527.5 4.7 7.8 2,903.9 6.6 15.7

Other hardwoods 6,977.3 2.3 3.5 19,069.0 3.4 10.5

Other softwoods 1,635.2 6.6 12.5 5,220.4 7.6 17.2

All species 36,205.2 1.1 5.7 106,950.6 1.6 11.4

Change 

(%) 

since 

2005 

Volume of live 

trees on forest 

land (million ft3

)

Change 

(%) 

since 

2005 

Volume of sawtimber 

trees on timberland 

(million bdft)

Rank Sampling 

error 

(%)

Sampling 

error 

(%)

Species
3

Forest Regeneration 

The first comprehensive report for Pennsylvania using the new annual forest inventory system (Bechtold and others 2005) 

found that “the most disturbing finding from the forest inventory is the general lack of understory plants and tree 

regeneration across much of Pennsylvania.” (McWilliams et al. 2007). This finding was based on the Pennsylvania 

Regeneration Study (PRS) that had been ongoing since 2001. Each year, 20 percent of the FIA plots are visited with PRS 

measurements being taken. The process requires 5 years to complete a full cycle of measurements of all the plots. The first 

inventory provided baseline measurements for the period 2001-2005. The completion of the 2010 field work represents the 

first re-measurement (2006-2010) .

The PRS evaluates forest understory and overstory relationships and specifically, the adequacy of advance tree-seedling 

and sapling regeneration (ATSSR). Ultimately, it is this component of trees that will replace the existing high-canopy trees 

(Marquis 1994). Only samples with adequate light for seedling establishment and development, or from 40- to 75-percent 

stocked are analyzed. Stands with less than 40 percent stocking have more available light, but are not included in the 

analysis because often these conditions are the result of poor management practices with little chance of improvement. 

Stand conditions that are more than 75-percent stocked do not generally receive enough light for adequate regeneration 

establishment. Eliminating these stocking classes provides better focus on the deer-soil-plant interactions that are at the 

center of the forest regeneration issue in Pennsylvania.

The percentage of plots with adequate ATSSR for 2001-2005 was 51 percent compared to 48 percent for 2006-2010. This 

illustrates the severity of understory conditions and the long-term nature of expected ecosystem response. It should be 

noted the difference between the two estimates are not statistically significant. The current results by ecopolitical region 

range from 38 percent in the southeast region to 51 percent in the southwest and northeast regions (Fig. 5).

51 

(n=119)

44

(n=36)

47 

(n=154)

38

(n=26)

51 

(n=86)

48 

(n=102)

Figure 5. - Percentage of samples adequately stocked with advance tree seedling and sapling regeneration for 

canopy replacement species and samples 40- to-75-percent stocked, by ecopolitical region, Pennsylvania, 

2006-2010. The number of samples (n) is in parentheses.
Bechtold, W.A.; Patterson, P.L. eds. 2005. The enhanced Forest Inventory and Analysis program: national sampling design 

and estimation procedures. Gen. Tech. Rep. SRS-80. Asheville, NC: U.S. Department of Agriculture, Forest Service, 

Southern Research Station. 85 p.

Marquis, David A., ed. 1994. Quantitative silviculture for hardwood forests of the Alleghenies. Gen. Tech. Rep. NE-183.

Radnor, PA: U.S. Department of Agriculture Forest Service, Northeastern Forest Experiment Station. 128 p.

Smith, W.B. 2002. Forest inventory and analysis: a national inventory and monitoring program. Environmental Pollution. 

116: 233-242.

USDA Forest Service. 2009. Forest inventory and analysis national core field guide, Vol. 1, field data collection procedures 

for Phase 2 plots, Ver. 5.0. Washington, DC: U.S. Department of Agriculture, Forest Service. Available at 

www.fia.fs.fed.us/library/field-guides-methods-proc(verified July 2009). 

FIA Program Information

McCaskill, G.L.; McWilliams, W.H.; Barnett, C.J. 2011. Pennsylvania’s forest resources, 2010. Res. Note NRS-122. 

Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 4 p.

Citation for this Publication

4

Additional Pennsylvania Inventory Information

Ferguson, Roland H. 1955. The timber resources of Pennsylvania. Upper Darby, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Forest Experiment Station. 46 p.

Ferguson, Roland H. 1968. The timber resources of Pennsylvania. Resour. Bull. NE-8. Upper Darby, PA: U.S. Department 

of Agriculture, Forest Service, Northeastern Forest Experiment Station. 145 p.

Considine, Thomas J.; Powel, Douglas S. 1980. Forest statistics for Pennsylvania--1978. Resour. Bull. NE-65. Broomall, 

PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 88 p.

Alerich, Carol A. 1993. Forest statistics for Pennsylvania--1978 and 1989. Res. Bull. NE-126. Radnor, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 244 p.

Widmann, Richard H. 1995. Forest Resources of Pennsylvania . Res. Bull. NE-131. Radnor, PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest Experiment Station. 41 p.

McWilliams, William H.; Stout, Susan L.; Bowersox, Todd W.; McCormick, Larry H. 1995. Advance tree-seedling 

regeneration and herbaceous cover in Pennsylvania forests. Northern Journal of Applied Forestry. 12(4): 187-191.

McWilliams, William H.; Cassell, Seth P.; Alerich, Carol L.; Butler, Brett J.; Hoppus, Michael L.; Horsley, Stephen B.; 

Lister, Andrew J.; Lister, Tonya W.; Morin, Randall S.; Perry, Charles H.; Westfall, James A.; Wharton, Eric H;. Woodall, 

Christopher W. 2007. Pennsylvania’s Forest, 2004. Resour. Bull. NRS-20. Newtown Square, PA: U.S. Department of 

Agriculture, Forest Service, Northern Research Station. 86 p.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, 

color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual 

orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any 

public assistance program (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternate 

means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET 

Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 

1400 Independence Avenue, S.W., Washington, DC 20250-9410, or call (800)795-3272 (voice) or (202)720-6382 (TDD). 

USDA is an equal opportunity provider and employer.

Contact Information Pennsylvania Analyst: Will McWilliams 610-557-4050 wmcwilliams@fs.fed.us

Data Acquisition / web sites: Carol L. Alerich, 610-557-4068, calerich@fs.fed.us

Website: fiatools.fs.fed.us