Penobscot Experimental Forest

[image] Map of Penobscot Experimental Forest with study area boundaries.

The year 2020 marks the 70th anniversary of the establishment of the Penobscot Experimental Forest (PEF) located in the towns of Bradley and Eddington in east-central Maine, about 10 miles north of the city of Bangor. This approximately 3,900-acre experimental forest was established in 1950 as a site for long-term U.S. Forest Service research. Though there are 22 experimental forests within the Northern Research Station footprint and 81 nationwide, the PEF is the only one in the transitional zone between the eastern broadleaf and boreal forests known as the Acadian Region. The PEF thus serves as an important and unique source of information about the ecology and silviculture of mixed-species northern conifers.

The early experiments conducted on the PEF were guided by regional forest management needs and questions of interest to public and private land managers, including the pulp and paper industry in New England.  The first experiment on the PEF was a Management Intensity Demonstration (also called Cutting Practice Level Study) in which various silviculture practices such as selection, diameter-limit, and other forms of partial cutting, as well as effects of degradation were studied and demonstrated.  Over time scientific investigations expanded to explore a variety of aspects of ecosystem structure and function.  This included tree and understory vegetation composition, leaf area and photosynthesis, genetic diversity, wildlife – habitat relationships, nutrient cycling, and carbon storage.

Experimental forests such as the PEF provide unique research opportunities across time and generations.  In addition to continuing studies over decades, sites of older studies may be repurposed to answer new questions or apply new technologies.  Photos of scientists at work on the PEF beginning in the 1950’s and continuing to the present illustrate the evolution in forest management equipment and practices.  They also demonstrate an increase in diversity of the researchers themselves.

Though originally owned by forest industry and leased to the Forest Service, the PEF is now owned by the University of Maine Foundation. Research on the PEF has resulted in more than 450 publications authored by Forest Service scientists and collaborators.  The research conducted on the forest has proved to be very important to people who live and work in the forest economy of this region.  The work also provides a lot of the foundational information about good and bad approaches to forest management (silviculture).  Forest Service and university scientists on the PEF work with students, host classes, and mentor graduate students helping ensure that a trained cadre of foresters is prepared to tackle issues of forest management and sustainability into the future. 

Video: Forestry for the Long Term -
Lessons in Sustainability from Maine's Penobscot Experimental Forest

Research on the PEF is critical to forest managers and policy makers throughout the region. Though initially established to study the production potential of a range of silvicultural practices, the research program on the PEF has expanded over time to include investigations of numerous aspects of ecosystem structure and function, including tree and understory vegetation composition, leaf area and photosynthesis, genetic diversity, wildlife – habitat relationships, nutrient cycling, and carbon storage. Today, Forest Service scientists, university partners, and other cooperators maintain long-term silvicultural experiments and conduct short-term observational and manipulative studies to better understand the mechanisms of ecosystem change over time.
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