fvs_remodeling

FVS Remodeling Project Repository

Maintainers:

• Greg Johnson
• David Marshall
• Aaron Weiskittel

This repo holds scripts and supporting files to re-model Forest Vegetation Simulator (FVS) component growth and imputation models for CONUS.

Some early priorities and project status are:

1. Establish a uniform site productivity measure for CONUS (perhaps similar to Climate SI, Embedded Climate data¹, or Asymptotic Above Ground Biomass).
2. Develop a robust system for establishing the age of a plot (or perhaps a tree).
3. Develop growth equations capable of unbiased estimate across all species.
   • A draft diameter growth equation (not using site index) has been developed for all species across CONUS with sufficient data ($\ge$ 5000 observations). There is good reduction in spatial residual variation. Draft results are here.
     • We are still working on refining the environmental effects (embedded climate variables).
     • There is still some spatial residual variation yet to address.
   • A draft height growth equation has been developed (not using site index) has been developed for all species across CONUS with sufficient data ($\ge$ 5000 observations). There is good reduction in spatial residual variation. Draft results are here.
     • Some parameters have biologically unreasonable signs (e.g., negative when positive is expected).
     • The crown ratio parameter is not significantly different from 0.0 for most species. We need to explore the ramifications of this.
     • We are still working on refining the environmental effects (embedded climate variables).
     • There is still some spatial residual variation yet to address.

Contacts:

• greg@nosnhoj.org
• davidkathymarshall@comcast.net
• aaron.weiskittel@maine.edu

Footnotes

1. Introduction to the Satellite Embedding Dataset. ↩