Overstory tree and regeneration data from the "Silvicultural Effects on Composition, Structure, and Growth" study at Penobscot Experimental Forest: 2nd edition

This data publication contains overstory tree measurements, regeneration data, and permanent sample plot location information collected between 1952 and 2014 under the study plan: FS-NRS-07-08-01 "Study Plan: Silvicultural effects on composition, structure and growth of northern conifers in the Acadian Forest Region: Revision of the Compartment Management Study on the Penobscot Experimental Forest" (see Methodology citation section). Data are available in six data sets. 1) Overstory tree measurement data include tree species, condition code (e.g., merchantability status and cause of mortality, if applicable), and diameter at breast height (dbh), 1952 to 2014. 2) Regeneration data include tree seedling species, presence, and count by height class, 1964 to 2014. 3) Spatial location data include location of a subsample of trees, 2000 to 2014. 4) Height and crown measurement data include tree height, height to crown base, and crown radii for a subsample of trees, 2000 to 2014. 5) Understory vegetation data include percent cover by substrate and non-tree vegetation categories, 2000 to 2014. 6) Permanent plot location data include the geospatial coordinates for permanent sample plots.
The primary objective of the long-term silvicultural study, called the Compartment Management Study, conducted by the USDA Forest Service at the Penobscot Experimental Forest (PEF) is to quantify tree and stand response to silvicultural treatment. Response variables include regeneration, species composition, and tree and stand growth, productivity, and quality. Data provide information about the interaction of natural and human disturbances and their effects on forest stand dynamics. A secondary objective of the study is to provide a variety of forest structures at one location to be used as the framework for short-term experiments in ecology and silviculture.
A number of revisions have been made to this long-term study over time, including but not limited to changes in silvicultural prescriptions (e.g., target residual basal areas, tree size thresholds for removals, and species composition goals), sampling protocols (e.g., numbers and sizes of sample plots, tree species and condition codes, and frequency of inventory), and response variables (e.g., overstory tree attributes, regeneration, and deadwood). The first edition of this data publication was published in 2012 (see Cross-Reference section). The second edition (published on 08/27/215) includes three years of additional data and corrections to data errors. The metadata have been revised to reflect these changes and a complete list of differences between the first and the second edition is located in the supplemental files (available with the full data publication download). On 12/12/2016 the metadata were updated to include more details to the methods section and other minor metadata updates. We strongly recommend that users read the study plans and accompanying documentation provided with the full data publication download before proceeding with data summary or analysis.