Question

How will forest inventories change in response to changes in land use, forest products markets, and environmental conditions?

Issues

• How will the distribution of forest tree species be influenced by changes described in the anticipated futures?
• How will anticipated futures affect the area of forests within the region? Define where forest area will be most stable and where change will be focused.
• How will anticipated futures alter forest inventory within the region, including measures of biomass, size classes, and forest types.
• How would anticipated futures affect the carbon flux and sequestration capacity of forests within the region?

Subregional Issues

• Conservation of coastal cypress-tupelo swamps in the Mississippi Valley (MAV)
• Increase in White Pine on ridges with fire exclusion (App-Cumb)
• Increase in Poplar post harvest (App-Cumb)
• Saltwater tolerant species/selections in coastal restoration (Coastal Plain)
• Saltwater incursion and regeneration and reestablishment of cypress forests (Coastal Plain)
• Declining forest types, specifically longleaf and shortleaf pine. (Piedmont)

Manager

Robert Huggett, North Carolina State University

Methods of Analysis

The Forest Dynamics Domain of the US Forest Assessment System will be used to simulate change in forest inventories over time. This model projects conditions at each plot within the existing forest inventory of each state using a set of transition probabilities attached to key plot attributes. Using stochastic modeling approaches, the condition of the new plot is generated to reflect timber harvesting, climate, forest aging, and natural succession. Once the condition of a plot is forecast then a historical plot with comparable conditions is selected to populate the future inventory. This imputation approach to generating future inventories allows for the full details of the inventory to be retained into the future.

Alternative inventories are generated in response to each scenario. Future inventories are sensitive to changes in land use (taken from forecast component A), timber harvesting driven by timber prices (taken from forecast component B), and climate futures (taken from Global Circulation Models and IPCC scenarios).

Data and Information Sources

The model is built from the most recent FIA inventory in each state. Transition models are built from observations of change in matched plots across multiple inventories linked to climate (e.g., temperature, precipitation, and potential evapotranspiration) and economic data (e.g., timber prices). Historical climate data are taken from PRISM datasets and forecasts of climate are taken from several IPCC scenarios and Global Circulation Models, downscaled for the 2010 RPA Assessment.

Products

We will generate forest inventories for each scenario evaluated on a decadal basis. Inventories are generated at the plot level and will be summarized in a variety of ways: states, survey units, sub regions, and portions of subregions. Data will be delivered as maps and as standard FIA tables for these subdivisions.

Potential cooperators

David Wear, Robert Abt (North Carolina State University), Ruhong Li (North Carolina State University), Linda Joyce (USFS Rocky Mountain Research Station) and John Coulston (USFS Southern Research Station).