Tanoak

(Last Revised 10/18/2002)

MRC's lands were originally dominated by redwood and Douglas-fir trees. Commercial harvesting of the MRC lands began in the 1850's and when the lands were initially entered, and for many decades after that, no replanting or reforestation efforts were made. In fact, much of the land was repeatedly burned to increase grazing potential. In addition, in the mid 1900's the lands were harvested with a pursuit of the highest value species, as opposed to a long term plan for the best management of the forest. As a result of these historical practices, MRC's lands now contain a substantial amount of a hardwood species called tanoak. Approximately 25% of MRC's standing timber volume is tanoak today, and approximately half of its growing space is dominated by tanoak trees.

While tanoak is a native species, it is also an invasive one. MRC is working to control tanoak and replant its forestland with redwood and Douglas-fir seedlings. Tanoak has been a long ignored problem on the North Coast, and MRC is committed to reclaiming redwood and Douglas-fir growing ground for the health of the forest in the long term. MRC's forest will always contain a certain amount of tanoak, particularly because tanoak is a vigorous stump sprouting tree (like redwood, it regenerates from the stump when it is cut). However, MRC will work to reduce this component of its forest in favor of the naturally dominant redwood and Douglas-fir.

Addressing the tanoak component of our forest is the primary reason we use herbicides on our property (hand application of herbicide to tanoak allows planted redwood and Douglas-fir seedlings to compete with the vigorous tanoak stump sprout). Tanoak dominated stands are also where we use our heaviest harvest prescriptions, such as variable retention. Since MRC is pursuing sustainable forestry methods, once the tanoak has been brought back into balance with other species, MRC's forest of the future will not require either herbicides or the same use of heavy harvest prescriptions.

Treatment of tanoak is currently conducted at a financial loss, but is necessary to continue to restore the conifer forest to MRC's lands. In 1999 and 2000, Mendocino Forest Products attempted to utilize a portion of the tanoak by retooling an older sawmill to produce hardwood flooring and start a firewood program. This operation was designed to offset the costs of the tanoak removal program but operated at a loss and has been closed.

We now are treating tanoak in the woods, primarily by applying small amounts of herbicide to standing trees. Thus far, we are encouraged by the results of these treatments. As the standing tanoak trees gradually lose their leaves, they continue to provide shade and shelter for the conifers newly planted underneath. As the decomposition of the tanoak accelerates, the fine limbs and then the trunks slowly decompose which returns 100% of the biomass to the soil thus increasing soil fertility and moisture holding capacity. This is particularly beneficial to forest soils where decades of continual burning have left the soils depleted and vulnerable to erosion.