Climate change risk matrix for forest ecosystem carbon pools in the US. Likelihood of change in carbon stocks is based on the coefficient of variation of median forest carbon stock densities among K�ppen-Geiger climate regions (i.e., x-axis) based on the national forest inventory plot network. Size of carbon stocks are based on the US National Greenhouse Gas Inventory (i.e., y-axis). Societal response (e.g., immediate adaptive response or periodic monitoring) to climate change events depends on the size and relative likelihood of change in stocks. Year 2100 projections are based on linear extrapolations of current carbon stocks and imputing current median carbon pool densities by climate region to projected future climate regions for calculation of coefficients of variation. The soil organic carbon pool exhibits the highest variability among climate regions and therefore may be most affected by climate change or climate change induced disturbance events. In contrast, the dead wood pool has a relatively small stock with low variability among climate regions. Explicit climate change effects are not incorporated into this matrix as they represent a number of complex feedbacks both between stocks (e.g., live aboveground biomass transitioning to the dead wood pool) and the atmosphere (e.g., forest floor decay). USDA Forest Service. | Snapshot : Forest Service scientists propose a basic approach to assess global change risks to forest carbon stocks in the U.S., which builds on the current U.S. forest inventory coupled with current and projected climatic regions
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