Folks, here are a few brief excerpts from a lengthy (552 pages) report, “AB 1504 California Forest Ecosystem and Harvested Wood Product Carbon Inventory: 2017 Reporting Period, FINAL REPORT.” The report was “completed through an agreement between the U.S. Forest Service…, the California Department of Forestry and Fire Protection…, and the University of Montana.”
“The 2017 reporting period annual rate of carbon sequestration for just the forest ecosystem pools is 29.2 MMT CO2e per year. This value is down by approximately 2.2 MMT CO2e per year from the 2016 measurement cycle. This reduction in carbon sequestration is the result of several factors including improvements in inventory methodology but is also being driven by two complementary factors; an increased rate of tree mortality and decreased gross growth rate on live trees during the most recent measurement years. Tree mortality regardless of cause, accounted for an additional 2.5 MMT of CO2e converted to dead wood annually. Gross growth on trees measured 10-years earlier declined by 1.2 MMT CO2e annually further reducing the net rate of sequestration.”
“In many forest types, current stocking levels reflect over a century of fire suppression and may not represent stand densities that are resilient to disturbances common to California forests such as fire or pest outbreaks. Additionally, as the forests age in unharvested stands, growth rates slow. Older forests tend to store more carbon, but they might not accumulate new carbon as quickly as younger, fast-growing stands. Consequently, the stocks and flux represented in this report may not be sustainable into the future without forest management given the uncertainty in potential effects from climate change, the current level of forest disturbances from wildfire and pests, and aging of forests on federal lands. From the 2015 reporting cycle, we are already beginning to see drought effects on tree growth and mortality. Forests provide many other services beyond carbon sequestration and storage, so there are many other considerations beyond forest carbon dynamics when developing management actions.”
<<Selected bullet points that reference National Forest lands, from Section 1, Executive summary and key findings:>>
• The national forests account for 35% of the statewide annual flux at a rate of 10.3 ± 2.8 MMT CO2e per year (figure 4.1).
• Only on reserved forest lands managed by the Forest Service is live tree growth not currently estimated to exceed carbon losses from the live tree pool due to tree mortality (Figure 4.4a, Table 4.4a).
• Annual gross growth per acre on live trees is currently exceeding all other carbon losses from the live tree pool due to mortality or harvest on unreserved timberland for all ownerships including lands managed by the Forest Service.
• The Shasta-Trinity National Forest has the highest net annual carbon sequestration rate for all forest pools at approximately 2.7 ± 0.9 MMT CO2e per year (Table 4.6b).
• There are four national forests in California currently experiencing a net loss of carbon based on all pools; San Bernardino (-0.3 ± 0.3 MMT CO2e per year), Los Padres (-0.3 ± 0.4 MMT CO2e per year), Angeles (-0.05 ± 0.2 MMT CO2e per year, and the Lake Tahoe Basin (-0.07 ± 0.2 MMT CO2e per year) (Table 4.6c).