Scientists & Staff

Education

• NY State College of Forestry, M.F. Forest Management, 1956
• NY State College of Forestry, B.S. Forestry, 1953

Professional Organizations

• Fellow, Society of American Foresters
• NH Timberland Owners Association

Featured Publications & Products

• Leak, William B.; Yamasaki, Mariko. 2010. Seventy-year record of changes in the composition of overstory species by elevation on the Bartlett Experimental Forest. Res. Pap. NRS-13. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 12 p.
• Leak, William B.; Gove, Jeffrey H. 2008. Growth of northern hardwoods in New England: a 25-year update. Northern Journal of Applied Forestry. 25(2): 103-105.
• Sendak, Paul E.; Leak, William B. 2008. Early crop-tree release and species cleaning in young northern hardwoods: a financial analysis. Res. Pap. NRS-6. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 13 p.
• Fast, Andrew J.; Ducey, Mark J.; Gove, Jeffrey H.; Leak, William B. 2008. Dating tree mortality using log decay in the White Mountains of New Hampshire. Northern Journal of Applied Forestry. 25(3): 154-157.
• DeGraaf, Richard M.; Lester, Anna M.; Yamasaki, Mariko; Leak, William B. 2007. Visual simulations of forest wildlife habitat structure, change, and landscape context in New England. Northern Journal of Applied Forestry. 24(3): 218-226.

Publications & Products

• Rogers, Nicole S.; D'Amato, Anthony W.; Leak, William B. 2021. Long-term evolution of composition and structure after repeated group selection over eight decades. Canadian Journal of Forest Research
• Leak, William B.; Yamasaki, Mariko ; Bennett, Karen P.; Desmarais, Ken ; Pohl, Peter ; Costello, Christine ; Munck, Isabel. 2020. White pine silviculture for timber and wildlife habitat in New England. Durham, NH: University of New Hampshire Cooperative Extension, ​34 p.
• Leak, William B. 2015. Dominant-tree thinning in New England northern hardwoods—a second look. Res. Note NRS-201. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 3 p.
• Leak, William B.; Yamasaki, Mariko; Holleran, Robbo. 2014. Silvicultural guide for northern hardwoods in the northeast. Gen. Tech. Rep. NRS-132. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 46 p.
• Yamasaki, Mariko; Costello, Christine A.; Leak, William B. 2014. Effects of clearcutting, patch cutting, and low-density shelterwoods on breeding birds and tree regeneration in New Hampshire northern hardwoods. Res. Pap. NRS- 26. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 15 p.
• Leak, Bill. 2013. Long-term research -- why do we do it?. In: Camp, Ann E.; Irland, Lloyd C.; Carroll, Charles J.W. Long-term silvicultural and ecological studies. Results for science and management: volume 2.GISF Res. Pap. 013. New Haven, CT: Yale University, School of Forestry and Environmental Studies, Global Institute of Sustainable Forestry: iii.
• Leak, William B.; Yamasaki, Mariko. 2013. Effects of low-density thinning in a declining white pine stand in Maine. Res. Note NRS-170. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 6 p.
• Leak, William B.; Yamasaki, Mariko. 2013. Regeneration of upper-elevation red oak in the White Mountains of New Hampshire. Res. Note NRS-161. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 5 p.
• Hoover, Coeli M.; Leak, William B.; Keel, Brian G. 2012. Benchmark carbon stocks from old-growth forests in northern New England, USA. Forest Ecology and Management. 266: 108-114.
• Leak, William B.; Yamasaki, Mariko. 2012. Historical (1899) age and structural characteristics of an old-growth northern hardwood stand in New York State. Res. Note NRS-144. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 11 p.
• Leak, William B.; Yamasaki, Mariko. 2012. Tree species migration studies in the White Mountains of New Hampshire. Res. Pap. NRS-19. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 8 p.
• Leak, William B.; Yamasaki, Mariko. 2012. 80 Years of thinning research on northern hardwoods in the Bartlett Experimental Forest, New Hampshire. Res. Pap. NRS-20. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 8 p.
• Leak, William B. 2011. Estimating allowable-cut by area-scheduling. Res. Note NRS-115. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 4 p.
• Leak, William B. 2011. Historical (1749-1899) vs. present-day sugar maple and beech diameter growth in the northeast. Res. Pap. NRS-16. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 4 p.
• Leak, William B.; Yamasaki, Mariko. 2011. The Bartlett Experimental Forest, Its first 75 years. NRS-INF-12-11. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 21 p.
• Leak, William B. 2009. Seventy years of understory development by elevation class in a New Hampshire mixed forest: management implications. Northern Journal of Applied Forestry 26(4): 164-166.
• Leak, William. 2007. Thinning northern hardwoods in New England by dominant-tree removal — early results. Northern journal of Applied Forestry. 24(4): 312-313.
• Leak, William B. 2007. Accuracy of regeneration surveys in New England northern hardwoods. Northern Journal of Applied Forestry. 24(3): 227-229.
• DeGraaf, Richard M.; Yamasaki, Mariko ; Leak, William B.; Lester, Anna M. 2006. Technical guide to forest wildlife habitat management in New England. Burlington, VT: University of Vermont Press, and Hanover, NH: University Press of New England. 305 p.
• Leak, William B. 2006. Fifty-year impacts of the beech bark disease in the Bartlett Experimental Forest, New Hampshire. Nourthern Journal of Applied Forestry 23(2):141-143
• Sendak, Paul E.; Frank, Robert M.; Leak, William B. 2006. Long-term data from silvicultural studies: interpreting and assessing old records for economic insights. In: Irland, Lloyd C.; Camp, Ann E.; Brissette, John C.; and Donohew, Zachary R., eds. Long-term Silvicultural & Ecological Studies: Results for Science and Management. New Haven, CT: Yale University: 203-207
• Yamasaki, Mariko; Leak, William B. 2006. Snag longevity in managed northern hardwoods. Northern Journal of Applied Forestry 23(3):215-217
• DeGraaf, Richard M.; Yamasaki, Mariko ; Leak, William B.; Lester, Anna M. 2005. Landowner's guide to wildlife habitat, forest management for the New England Region. Burlington, VT: University of Vermont Press and Hanover, NH: University Press of New England. 111 p.
• Desmarais, Kenneth M.; Leak, William B.; Leak, William B. 2005. Ten-Year Performance of Eastern White Pine - under a Crop Tree Release Regime on an Outwash Site. Northern Journal of Applied Forestry. 22(2): 139-142.
• Innes, J. C.; Ducey, M. J.; Gove, J. H.; Leak, W. B.; Barrett, J. P. 2005. Size-density metrics, leaf area, and productivity in eastern white pine. Canadian Journal of Forest Research 35:2469-2478
• Leak, William B.; Leak, William B. 2005. Effects of Small Patch Cutting on Sugar Maple Regeneration in New Hampshire Northern Hardwoods. Northern Journal of Applied Forestry. 22(1): 68-70.
• Leak, William B. 2004. Diameter Growth in Even- and Uneven-Aged Northern Hardwoods in New Hampshire Under Partial Cutting. Northern Journal of Applied Forestry. 21(3): 160-163.
• Leak, William B. 2003. Regeneration of Patch Harvests in Even-Aged Northern Hardwoods in New England. Northern Journal of Applied Forestry. 20(4): 188-189.
• Leak, William B. 2003. Best density and structure for uneven-aged northern hardwood management in New England. Northern Journal of Applied Forestry. 20(1): 43-44.
• Leak, William B. 2002. Origin of sigmoid diameter distributions. Res. Pap. NE-718. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 10 p.
• Leak, William B.; Sendak, Paul E. 2002. Changes in species, grade, and structure over 48 years in a managed New England northern hardwood stand. Northern Journal of Applied Forestry. 19(1): 25-27.
• Solomon, Dale S.; Leak, William B. 2002. Modeling the regeneration of northern hardwoods with FOREGEN. Res. Pap. NE-719. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 9 p.
• Zhang, Lianjun; Gove, Jeffrey H.; Liu, Chuangmin; Leak, William B. 2001. A finite mixture of two Weibull distributions for modeling the diameter distributions of rotated-sigmoid, uneven-aged stands. Canadian Journal of Forest Research. 31: 1654-1659.
• Costello, Christine A.; Yamasaki, Mariko; Pekins, Peter J.; Leak, William B.; Neefus, Christopher D. 2000. Songbird response to group selection harvests and clearcuts in a New Hampshire northern hardwood forest. Forest Ecology and Management. 127: 41-54.
• Solomon, Dale S.; Leak, William B. 2000. Growth and stocking of eastern hemlock (Tsuga canadensis) in New England. In: McManus, Katherine A.; Shields, Kathleen S.; Souto, Dennis R., eds. Proceedings: Symposium on sustainable management of hemlock ecosystems in eastern North America. Gen. Tech. Rep. NE-267. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 43-49.
• Leak, William B. 1999. Stand Structure in Evenaged Northern Hardwoods: Development and Silvicultural Implications. Northern Journal of Applied Forestry. 16(2): 115-119.
• Leak, William B.; Lamson, Neil I. 1999. Revised white pine stocking guide for managed stands. NA-TP-01-99. U.S. Department of Agriculture, Forest Service, Northeastern Area State and Private Forestry. 2 p.
• Leak, William B.; Yamasaki, Mariko; Kittredge, David B., Jr.; Lamson, Neil I.; Smith, Marie-Louise. 1997. Applied ecosystem management on nonindustrial forest land. . Gen. Tech. Rep. NE-239. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 30 p.
• Nowak, Chris; Stout, Susan; Brissette, John; Kenefic, Laura; Miller, Gary; Leak, Bill; Yaussy, Dan; Schuler, Tom; Gottschalk, Kurt. 1997. Defining the role of silvicultural research in the Northeastern Forest Experiment Station. In: Communicating the role of silviculture in managing the national forests: Proceedings of the National Silviculture Workshop. 1997 May 19-22; Warren, PA.: Gen. Tech. Rep. NE-238. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 115-122.
• Leak, William B. 1996. Long-term structural change in uneven-aged northern hardwoods. Forest Science. 42(2): 160-165.
• Solomon, Dale S.; Leak, William B. 1996. Evaluation of methodology for detecting/predicting migration of forest species. In: Hom, John; Birdsey, Richard; O'Brian, Kelly, eds. Proceedings 1995 meeting of the northern global change program; Gen. Tech. Rep. NE-214. Radnor, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 175-182.
• Leak, William B.; Cullen, J.B.; Frieswyk, Thomas S. 1995. Dynamics of whlte pine in New England. Res. Pap. NE-699. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 8 p.
• Solomon, Dale S.; Herman, David A.; Leak, William B. 1995. FIBER 3.0: An Ecological Growth Model for Northeastern Forest Types. Gen. Tech. Rep. NE-204. Radnor, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 24 p.
• Leak, William B.; Yamasaki, Mariko; Smith, Marie-Louise; Funk, David T. 1994. Selection criteria for forested natural areas in New England, USA. Natual Areas Journal. 14(4): 300-305.
• Solomon, Dale S.; Leak, William B. 1994. Migration of tree species in New England based on elevational and regional analyses. Res. Pap. NE-688. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 9 p.
• Leak, William B.; Graber, Raymond E.; Graber, Raymond E. 1993. Six-year beechnut production in New Hampshire. Res. Pap. NE-677. Radnor, PA: US. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 6 p.
• DeGraaf, Richard M.; Yamasaki, Mariko; Leak, William B.; Lanier, John W. 1992. New England wildlife: management forested habitats. Gen. Tech. Rep. NE-144. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 271 p.
• Graber, Raymond E.; Leak, William B.; Leak, William B. 1992. Seed fall in an oldgrowth northern hardwood forest. Res. Pap. NE-663. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 11 p.
• Hornbeck, J.W.; Leak, W.B. 1992. Ecology and management of northern hardwood forests in New England. Gen. Tech. Rep. NE-159. Radnor, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment 44 p.
• Leak, W.B.; Leak, W.B. 1987. Characteristics of Five Climax Stands in New Hampshire. Res. Note NE-336. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 5 p.
• Leak, William B.; Solomon, Dale S.; DeBald, Paul S. 1987. Silvicultural guide for northern hardwood types in the Northeast (revised). Res. Pap. NE-603. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 36 p.
• Solomon, Dale S.; Leak, William B.; Leak, William B. 1986. Simulated yields for managed northern hardwood stands. Res. Pap. NE-578. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 24 p.
• Leak, William B.; Leak, William B. 1985. Relationships of tree age to diameter in old-growth northern hardwoods and spruce-fir. Res. Note NE-329. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 4 p.
• Leak, W. B.; Tubbs, C. H. 1983. Percent crown cover tables for applying the shelterwood system in New England. Research Note NE-313. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 4p.
• Leak, William B. 1983. Stocking, growth, and habitat relations in New Hampshire hardwoods. Res. Pap. NE-523. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiement Station. 11p.
• Leak, William B. 1982. Habitat mapping and interpretation in New England. Res. Pap. NE-496. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 28p.
• Leak, William B. 1980. Rapid economic analysis of northern hardwood stand improvement options. Research Note NE-296. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 6 p.
• Leak, William B. 1979. Effects of habitat on stand productivity in the White Mountains of New Hampshire. Res. Pap. NE-452. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 8p.
• Leak, William B.; Riddle, Jane R. 1979. Why trees grow where they do in New Hampshire Forests. NE-INF-37-79. Broomall, Pennsylvania: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 26p.
• Lancaster, Kenneth F.; Leak, William B. 1978. A silvicultural guide for white pine in the northeast. Gen. Tech. Rep. NE-41. Broomall, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 13 p.
• Leak, W. B. 1978. Relationship of Species and Site Index to Habitat in the White Mountains of New Hampshire. Res. Pap. NE-397. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 9p.
• Leak, William B. 1978. Relationships of forest vegetation to habitat on two types of glacial drift in New Hampshire. Research Note NE-257. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 5 p.
• Leak, W. B. 1976. Relation of Tolerant Species to Habitat in the White Mountains of New Hampshire. Res. Pap. NE-351. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 10p.
• Leak, W. B.; Solomon, Dale S. 1975. Influence of residual stand density on regeneration of northern hardwoods. Res. Pap. NE-310. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 7p.
• Leak, William B.; Filip, Stanley M. 1975. Uneven-aged management of northern hardwoods in New England. Res. Pap. NE-332. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 15p.
• Leak, William B.; Martin, C. Wayne. 1975. Relationship of stand age to streamwater nitrate in New Hampshire. Research Note NE-211. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 5p.
• Leak, William B. 1974. Some effects of forest preservation. Research Note NE-186. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 4p.
• Leak, William B.; Graber, Raymond E. 1974. Forest vegetation related to elevation in the White Mountains of New Hampshire. Res. Pap. NE-299. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 7p.
• Leak, W. B. 1973. Species and structure of a virgin northern hardwood stand in New Hampshire. Research Note NE-181. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 4p.
• Philbrook, James S.; Barrett, James P.; Leak, William B. 1973. A stocking guide for eastern white pine. Research Note NE-168. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 3p.
• Leak, William B. 1970. Some preliminary estimates of energy utilization in even-aged northern hardwoods. Research Note NE-108. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 7p.
• Leak, William B.; Allen, Peter H.; Barrett, James P.; Beyer, Frank K.; Mader, Donald L.; Mawson, Joseph C.; Wilson, Robert K.; Wilson, Robert K. 1970. Yields of eastern white pine in New England related to age, site and stocking. Res. Pap. NE-176. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 15 p.
• Leak, William B.; Filip, Stanley M.; Filip, Stanley M. 1970. Cutting strategies and timber yields for unbalanced even-aged northern hardwood forests. Res. Pap. NE-153. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 19 p.
• Leak, William B. 1969. Financial maturity of yellow birch. In: Doolittle, W.T.; Bruns, P.E., comps. 1969. Birch symposium proceedings; 1969 August 19-21; Durham, NH. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 145-146.
• Leak, William B.; Solomon, Dale S.; Filip, Stanley M.; Filip, Stanley M. 1969. A silvicultural guide for northern hardwoods in the northeast. Res. Pap. NE-143. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 34 p.
• Solomon, Dale S.; Leak, William B. 1969. Stocking, growth, and yield of birch stands. In: Doolittle, W.T.; Bruns, P.E., comps. 1969. Birch symposium proceedings; 1969 August 19-21; Durham, NH. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 106-118.
• Leak, William B. 1968. Birch regeneration: a stochastic model. Research Note NE-85. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 7p.
• Leak, William B.; Filip, Stanley M.; Solomon, Dale S. 1968. Rates of value increase for yellow birch in New England. Res. Pap. NE-120. Upper Darby, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 11 p.
• Leak, William B. 1964. Estimating maximum allowable timber yields by linear programming. Res. Pap. NE-17. Upper Darby, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 9 p.
• Leak, William B. 1963. Effects of Seedbed, Overstory, and Understory on White Ash regeneration. Res. Pap. NE-2. Upper Darby, PA: U. S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 13 p.
• Filip, Stanley M.; Leak, William B. 1962. Profitable woodlot management in New England. Station Paper NE-170. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 17 p.
• Leak, William B. 1961. Development of second-growth northern hardwoods on Bartlett Experimental Forest - a 25-year record. Station Paper NE-155. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 1-8
• Filip, Stanley M.; Marquis, David A.; Leak, William B. 1960. Development of old-growth northern hardwoods on Bartlett Experimental Forest - a 22-year record. Station Paper NE-135. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 7 p.
• Leak, William B. 1958. Silvical characteristics of sweet birch (Betula lenta). Station Paper NE-113. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 14 p.
• Leak, William B.; Wilson, Robert W., Jr. 1958. Regeneration after cutting of old-growth northern hardwoods in New Hampshire. Station Paper NE-103. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 1-8

Research Datasets

• Leak, William B.; Yamasaki, Mariko; Belair, Ethan P.; Knapp, Rachel A.; Brissette, John C. 2017. Bartlett Experimental Forest permanent cruise plot data. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2017-0036.

National Research Highlights

Has Climate Affected Tree Species Distribution in New England?

Year: 2016

Remeasurement of plots 70 years after establishment on the White Mountain National Forest shows no evidence of changes in elevations among climate-sensitive species.

No Signifigant Losses of Stand Productivity From Whole-tree Harvesting and Clearcutting in New England Forests

Year: 2015

Silviculturalists have been concerned over nutrient losses from clearcutting and, more recently, whole-tree harvesting in New England since the late 1960s. Recent information from studies in New Hampshire and Maine show there are no significant losses of essential nutrients and stand productivity following these harvest methods.

Silvicultural Guide for Northern Hardwoods in the Northeast Updated

Year: 2014

This revision of the 1987 silvicultural guide updates and expands the silvicultural information on northern hardwoods. It provides additional information on wildlife habitat and managing mixed-wood and northern hardwood-oak stand.