Across the United States, governors are pushing their states to produce Climate Action plans that incorporate both community resilience and carbon sequestration across all sectors of the economy. However, establishing the need for and potential added benefit of carbon sequestration in forests can be challenging. Data that exist on the national level are not often accurate when scaled down to state or county regions. This work will create a state- and region- level forest carbon index for scientists, nonprofit professionals, and state- and federal- agency employees to use in assessing the current and future state of carbon sequestration on public and private forestland.
To develop a forest carbon index, we analyzed data from the US Forest Service Forest Inventory & Analysis (FIA) program. We retrieved carbon and acreage data by county, state, stand origin, and forest type. These data were manipulated to show a basic carbon index as a ratio of metric tonnes of carbon:acres. This value is reported as FCI (forest carbon index) below.
This ratio can be used to calculate: future carbon storage, "opportunity cost" of forest harvest, and the lost carbon opportunity from artificially regenerated (planted) acres vs. naturally regenerated acres.
Results/Conclusions
Using the calculated forest carbon index for North Carolina, we found the following:
- NC has an average FCI of 70.76 in naturally regenerated forests, regardless of forest type.
- In contract, NC's planted acres have an average FCI of 59.16.
- The opportunity cost (FCInatural - FCIplanted) in NC is 11.60.
- In young stands (0-20 yr), the FCI is slightly higher in planted acres (48.88) compared to natural acres (45.09), however, more than 95% of planted acres in NC are < 40 yr and commercial species (Loblolly/Slash), which indicates that they will likely be harvested before reaching mature or old-growth (> 80 yr) age.
- The top two forest type groups with maximum FCI in North Carolina, excluding stand origin, are "Spruce/Fir" (122.00), and "Oak/Gum/Cypress" (102.57).
- The two forest type groups with minimum FCI in North Carolina, excluding stand origin, are "Aspen/Birch" (29.11) and "Other Eastern Softwoods" (32.62)
Based on these results, we recommend that North Carolina prioritizes high FCI value forests (e.g., Spruce/Fir and Oak/Gum/Cypress) and relies on natural regeneration, because planted forests on average have lower FCI throughout the life of a forest stand.