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Henry Gerhold, Ph.D.

  • Professor Emeritus of Forest Genetics
Henry Gerhold, Ph.D.

University Park, PA 16802
Email:
Work Phone: 814-865-7541

Education

  1. B.S., The Pennsylvania State University (1952)
  2. M.F., The Pennsylvania State University (1954)
  3. Ph.D., Yale University (1959)

Academic Interests:

Genetic improvement of landscape trees, Christmas trees, and timber species; management of municipal trees; urban forestry extension education

Professional Affiliation:

Assistant Director, Research and Graduate Studies (1985-1992); Interim Director, School of Forest Resources (1988); Chairman, Intercollege Graduate Degree Program in Genetics (1979-1982); Executive Director, Metropolitan Tree Improvement Alliance (1975-1980)

Recent Research/Educational Projects:

Performance Tests of Street Trees The performance of cultivars as street trees is being tested through a cooperative program supported by utilities and state forestry agencies. In 12 years 59 cultivars in 10 genera were planted in 76 communities, about 5,000 trees in all. Annual measurements of growth, health, and maintenance needs are being evaluated to aid in selecting trees best adapted to various site conditions and urban stresses. In a related study, the book Landscape Tree Factsheets was compiled from a variety of publications and interviews with arboricultural experts. The factsheets on 225 species and cultivars contain standardized information and color photos of trees adapted to temperate climates. An index of sixteen tree characteristics was constructed for use in selecting trees that can withstand various site conditions and urban stresses.

Community Forestry in Pennsylvania Two surveys tracked the development of municipal tree programs during 1991 to 1993. Only 28% of the cities and boroughs had any kind of tree program in 1991, and many communities were aware that their trees needed attention and expressed a desire for technical assistance. An evaluation of America the Beautiful grants for tree planting and tree care in Pennsylvania concluded the grants were effective in stimulating the development of municipal tree programs. The involvement of extension and service foresters was found to be beneficial in assuring technical proficiency and wise use of grant funds.

Christmas Tree Improvement Improved varieties of Scotch pine and Douglas-fir are being created through a series of genetic studies and breeding activities spanning many years and multiple generations. Selection and breeding methods were developed by research on heritability of traits, variation among provenances, crossability, isozymes, phenology of flowering, and racial hybridization. Seed orchards have been established, four improved varieties have been released, and genetic qualities of several more are being tested.

Selected Publications:

Gerhold, H.D. 2005. Landscape tree factsheets CD. School of Forest Resources, Penn State University.

Despot, D.A., and H.D. Gerhold. 2003. Preserving trees in construction projects: identifying incentives and barriers. Journal of Arboriculture 29(5): 267-280.

Gerhold, H.D., and A.D. Johnson. 2003. Root dimensions of landscape tree cultivars. Journal of Arboriculture 29(6): 322-326.

Johnson, A.D., and H.D. Gerhold. 2003. Carbon storage by urban tree cultivars, in roots and above-ground. Urban Forestry & Urban Greening 2(2): 65-72.

Gerhold, H.D. 2002. Our heritage of community trees. Penna. Urban & Community Forestry Council, Mechanicsburg PA. 74 p.

Gerhold, H. D. 2000. Crabapple cultivars tested as street trees: second report. J. Arboric. 26(1):48-54

Gerhold, H. D. 1993. Genetic improvement of Christmas trees. Amer. Christmas Tree J. 37(1):29-32.

Gerhold, H. D., N. L. Lacasse, and W. N. Wandell. 2001. Landscape Tree Factsheets. 3rd Ed. The Pennsylvania State University, Coll. Agric. Sci. 452 p.

Gerhold, H. D., W. Porter. 2000. Selecting trees for community landscapes. Chapt. 11 in "Handbook for Urban and Community Forestry in the Northeast", J. E. Kuser, Ed. Kluwer Academic/Plenum Publishers, N.Y. p 153-168.

Johnson, A. D., H. D. Gerhold. 2001. Carbon storage by utility-compatible trees. J. Arboric. 27(2): 57-68.

Kleinschmit, J., K. K. Khurana, H. D. Gerhold, and W. J. Libby. 1993. Past, present, and anticipated applications of clonal forestry. In Clonal Forestry II, Conservation and Application. Springer-Verlag, Berlin-Heidelberg. pp. 9-41.

Reeder, E. C. and H. D. Gerhold. 1993. Municipal tree programs in Pennsylvania. J. Arboric. 19(1):12-19.

Swartzmann, J. F. and H. D. Gerhold. 1991. Genetic structure and mating system of red oak in Pennsylvania. For. Sci. 37(5):1376-1389.

Kleinschmit, J., K. K. Khurana, H. D. Gerhold, and W. J. Libby. 1993. Past, present, and anticipated applications of clonal forestry. In Clonal Forestry II, Conservation and Application. Springer-Verlag, Berlin-Heidelberg. pp. 9-41.

Reeder, E. C. and H. D. Gerhold. 1993. Municipal tree programs in Pennsylvania. J. Arboric. 19(1):12-19.