Methodology used to develop the Northeastern Forest Regeneration Data Network

The initial inventory of projects related to tree regeneration, browse, and/or tree seed production were collated based on cooperator suggestions, professional contacts, known datasets, and search engine queries. Any project or dataset was considered for inclusion if it had a component of tree seedlings, tree saplings, browse presence/absence or intensity on the regeneration layer, or mature tree seed or flower production. We wanted to remain inclusive to all relevant resources that may have a methodology that could be adapted to another project. This work is a first round of dataset gathering, leaving many other appropriate projects to be added in a second version.

We developed a methods assessment framework to systematically evaluate each project included in this effort. In this framework, we catalogued the metadata, methods, and metrics collected. The assessment table was designed so it can be applied easily to additional programs and can accommodate a range of project types, but at the same time allow for easy comparison of projects and data analysis.

For each project, we assessed how easily it could be compared or integrated with FIA data. For each project, we ranked compatibility as Low, Medium, or High. High compatibility was assigned if there were permanent plots that were assessed over multiple inventories and if there were similar metrics to those in the FIA program. Medium compatibility was assigned if there was some similarity in metrics assessed or if the project could be compared with one aspect of FIA data – for example, if the project only assessed eastern hemlock regeneration, the project would only be compatible with FIA data for that one species. Low compatibility was assigned if the data collected was not comparable to specific FIA data, but could be compared generally.

For each project we assessed whether there was sufficient information to analyze seedling or sapling:

  • biomass
  • browse impact
  • density
  • mortality
  • relationship with overstory trees
  • species composition
  • effects of treatment or management

For each one of these analyses, we evaluated if the project had sufficient information based on the required data needed for that analysis.


Analysis Required Metrics
Density Species, count, plot size
Species Composition Tallies by species
Mortality Status (i.e. live and dead stems) or tracking of individual trees over time
Biomass Diameter, height
Browse Impacts Browse assessments
Change over time Data collected at two or more distinct points in time
Effects of treatment or management Data per treatment or management
Relationship with overstory trees Overstory tree data collected in the same locations as regeneration data

If there was sufficient information for the specified analysis, the project was assigned ‘suitable’. If the project contained some of the information required for the specified analysis, it was assigned ‘partially suitable’. This may mean that to complete the specified analysis, modeling or assumptions may be needed. If the project did not contain the information needed for the specified analysis, it was assigned ‘unsuitable’.

For more information please see the methods section in the Northeastern Forest Regeneration Data Network Technical Report