Scientists & Staff

Mary Ann Fajvan

Research Forester
180 Canfield St.
Morgantown, WV, 26505
Phone: 304-285-1575

Contact Mary Ann Fajvan

Current Research

  • In 2005-07 I established two new research projects using silvicultural treatments in an attempt to make stands more resistant to hemlock woolly adelgid (HWA) and beech bark disease. For HWA, I selected four non-infested hemlock stands on the Allegheny National Forest and designed a thinning study to reduce stand density and improve hemlock vigor before HWA attack. We are now expanding the study into New England. We will examine growth changes in released trees as well as monitor their foliar nutrient content over time. The objective of the beech bark disease study is to determine if visually resistant beech trees can serve as a source of resistant beech regeneration as part of the shelterwood regeneration method. The project is also on the Allegheny NF and involves using herbicides to eliminate nonresistant beech regeneration.
  • Two other new studies involve (1) modeling tree regeneration height growth in oak shelterwood studies and (2) using dendrochronolgy to model growth in mature oak forests.

Research Interests

My research program focuses on studies of stand dynamics and silviculture in oak-dominated forests and associated hemlock forests in response to natural and human disturbances, including invasive species. I would like to develop new projects that examine the combined disturbance effects of exploitative harvesting practices, invasive species, and over browsing by white-tailed deer on stand development.

Why This Research is Important

My research examines the dynamics of how forests change in relationship to natural and human disturbances. Understanding these ecological trends assists scientists, managers and landowners in maintaining forest sustainability.


  • University of Maine, Ph.D. Quantitative Silviculture, 1991
  • Yale School of Forestry and Environmental Studies, M.S. Silviculture, 1983
  • Rutgers University, Cook College, B.S. Natural Resource Management, 1981

Professional Organizations

  • Society of American Foresters (SAF)
  • Ecological Society of America

Featured Publications & Products

Publications & Products

National Research Highlights

High-quality stream on Tioga State Forest, Penn., located in the headwaters of the Chesapeake Bay.  Decline of eastern hemlock from hemlock woolly adelgid infestations, may affect the hydrology of the local watershed.

Collaboration seeks to preserve Chesapeake Bay Watershed health in the face of hemlock decline

Year: 2017

Few studies have examined how insect outbreaks affect landscape-level hydrologic processes. Anticipating hydrologic impacts resulting from the decline of hemlock trees in watersheds infested with hemlock wooly adelgid, Forest Service scientists are partnering with state and federal conservation agencies and nongovernmental organizations to devise management strategies for ameliorating hydrologic impacts from the pending decline of eastern hemlock in northern watersheds of the Chesapeake Bay.

Photo of hemlock tree crown released by the thinning treatment. Mary Ann Fajvan, U.S. Department of Agriculture Forest Service.

Thinning Effects on Foliar Elements in Eastern Hemlock: Implications for Managing the Spread of Hemlock Woolly Adlegid

Year: 2016

With the imminent entrance of hemlock woolly adlegid (HWA) into forest stands in the Allegheny National Forest in Pennsylvania, it was critical to understand whether silvicultural thinning results in increased foliage palatability for HWA. Forest Service research findings suggest that thinning may be used in hemlock stands without risking HWA attack due to increased needle nutritional value.

Last modified: Friday, October 7, 2022