California Board of Forestry
Policy and Management Committee
P.O. Box 944246
Sacramento, CA 94244 -2460
January 6, 2004

Dear Committee Members,

With regard to the Microclimate Petition presently before you, and Mr. Cafferata and Mr. Spittler's Memorandum to Mr. Snyder of January, 2002, we have the following preliminary remarks. (These remarks are preliminary since we didn't receive this communication until two hours ago). Mr. Cafferata and Mr. Spittler address landsliding and clearcuts in their memo.

What does science say about clearcutting and landsliding? 22 studies of landslides and clearcuts in the Pacific Northwest (reported by Doug Heiken, see References, "What Does Science Really Say?") give a clear indication. "Clearcuts and forest roads are associated with dramatic increases in both the number of slides and the volume of slides relative to natural forest conditions."

"Slide Risk for Clearcuts vs. Forested Areas

In terms of the number of slides per unit area, several of the studies indicate that clearcuts exhibit landslide rates up to 20 times higher than the background landslide rate observed in forested areas. (The average among all the data sets was 13x)

In terms of total slide volume per unit area, several of the studies showed that clearcuts exhibit soil transfer rates up to 8 times higher than forested areas. (The average among all the data sets was 7x) Slide Risk for Roadways vs. Forested Areas

In terms of the number of slides per unit area, several of the studies indicate that road rights-of-way exhibit landslide rates as much as 300 times higher than forested areas. (The average among all the data sets was 210x).

In terms of total slide volume per unit area, several of the studies showed that road rights-of-way exhibit soil transfer rates up to 200 times higher than forested areas. (The average among all the data sets was 103x)" [Ibid]

We also note, (from "Clearcutting Causes Landslides", see References below):

Scientific studies for more than twenty five years have proven over and over that clearcutting causes very large increases in landslides. The American Fisheries Society is the independent professional society for fisheries scientists. The Society's 1991 publication Influences of Forest and Rangeland Management on Salmonid Fishes and their Habitats [William R Meehan ed, AFS 1991] reviewed all the scientific literature, and concluded:

"The frequency of mass erosion [landslides, debris flows, earthflows, etc] is strongly linked to the type and intensity of land treatment in the basin. Although most mass movements are associated with roads and their drainage systems, many originate on open slopes after logging has raised soil water tables and decreased root strength." [Meehan, 1991 page 194]

"The increase in mass movement due to clear cutting varies widely, ranging from 2-4 times in Oregon and Washington...to 31 times in the Queen Charlotte Islands... An increase of 6.6 times...is probably closer to the norm." [Meehan, 1991, page 194]

In other words, scientific studies show that clearcutting, at a minimum, doubles or quadruples the number of landslides, and the average effect is much greater yet.

Clearly, then, reducing the frequency of clearcuts (including less road-building), as the Microclimate Rule proposes to do (see: http://www.rrraul.org/BOF_8_6_03/LibeuMicroclimateRule.html), will reduce the risk of the disasters attendant upon landsliding.

What are such disasters? The Gualala and its tributaries has been listed for sediment (and for temperature) by Water Quality and the EPA. The Salmon have almost disappeared. The Gualala is in many places filled with silt, even running underground..See images, for example, at: http://www.rrraul.org/Angels.html. Are the current Forest Practice Rules good enough? -- These listings have come about under the current Rules. When is the Board going to address these issues?

Sincerely,
Jay Halcomb, RRRAUL
http://www.rrraul.org

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References (copies attached):

"Clearcutting Causes Landslides", Umpqua Watersheds Website: http://www.umpqua-watersheds.org/local/landslides/slides.html#fsStudy

Heiken, Doug, March 6, 1997: "LANDSLIDES AND CLEARCUTS: What Does The Science Really Say?", Umpqua Watersheds Website: http://www.umpqua-watersheds.org/local/landslides/slide_studies.html

Spittler and Cafferata, Jan. 6, 2004: "Erosion Memorandum"