Setting the Stage, Part 1

If you live in Ashland, you’ve probably seen log trucks rumbling out of the watershed. It might be easy to dismiss this activity as just “logging,” but did you know that removing these trees is crucial for restoring ecological health to the Ashland Watershed? To find out how, read on! 

The Ashland Watershed viewed from Wagner Butte. Our forest is beautiful, but it needs our help.

Our forest has a problem: ironically, there are too many trees and not enough resources (i.e. water, light, nutrients) for them to thrive. This is because society has been aggressively suppressing fire for the last century. For thousands of years before suppression, both lightning and Native Americans started fires in the watershed. Most groves experienced a fire each decade, a frequency that kept the forest relatively open. By excluding fire, we’ve created a forest that is unnaturally dense, which poses a wildfire risk and degrades habitat for many plants and animals. Ultimately, we need to reintroduce fire, but first we need to reverse these unintended consequences.

Fire suppressed forests become extremely dense with young trees, like these Douglas-firs (Pseudotsuga menziesii). Fuels this high pose a risk to people and forests.

You see, simply allowing the forest to burn today could produce severe wildfires due to the accumulation of fuel during fire suppression. On the other hand, many of the trees that need to be thinned are now large enough to survive the lower heat of controlled burns. So the first step in Ashland Forest Resiliency’s (AFR) restoration is to reduce tree density, primarily in the Rogue River-Siskiyou National Forest. To do this, local forest professionals with Lomakatsi Restoration Project, an AFR partner, select the trees that make the most ecological sense to remove, following guidelines developed by The Nature Conservancy and US Forest Service professionals. It is important to note that these are not clear cuts. At a bare minimum, we retain 40% canopy closure, although 70% is much more typical. The trees that remain (which include all trees greater than 150 years old) and understory plants benefit from decreased competition afterwards.

Selective tree harvest gives understory plants, like these Henderson’s fawn lilies (Erythronium hendersonii), a chance to grow.

In many parts of the watershed, the trees selected for removal are large enough to sell to a local timber mill. We refer to these restoration treatments as commercial density management. As part of AFR monitoring, we record the diameter and species of every tree we commercially harvest; the chart below comes from those data. As you can see, most of the removed trees are young Douglas-firs and white firs (Abies concolor). Those species are less adapted to fire and became unnaturally abundant during suppression.

The majority of trees harvested for AFR were 8-12 inch diameter Douglas-firs and white firs. Relatively few trees greater than 18 inches were removed, and from field reviews we know that they were removed to protect much larger and older ones.

It’s important to realize that as beautiful as our Ashland Watershed is, it is not pristine. Spending millions of dollars putting out fires for a century has had serious consequences on the forest. We now understand that fire is a natural part of the forest ecosystem and that we need to reintroduce it, but first we need to set the stage. Check out our next post to see how!

Frequent, mild fires are an essential part of our forest’s ecosystem, but reintroducing them requires undoing the effects of fire suppression.

Lead author: Evan Barrientos, SW Oregon Monitoring and Outreach  Assistant, The Nature Conservancy, and Ashland Forest Resiliency team member