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Abstract
Tree removal associated with clearcutting in a coastal redwood forest does not alone initiate numerous shallow landslides that deliver large quantities of sediment to watercourses. landslide inventory focused on the relationship between vegetation removal in predominantly second-growth redwood forest and shallow landslides. Deep-seated dormant landslide features were mapped to record if reactivation had occurred within clearcuts. field-based inventory included mapping all fifty clearcut units and characterizing landslides by type, cause, age, sediment delivery and stream classification. Thirty-two active landslides were found; and all except two were associated with older roads. The percent of the landslide volume to the volume of landslide sediment reaching a watercourse for each watershed varied from 34 to 75 percent delivery. Sediment delivery depended on proximity of the road to higher order watercourses. Many deep-seated dormant rockslides were mapped within clearcut units with no reactivation except within old road fills. Mapping nearby uncut or partially cut control units with similar slope characteristics as the clearcuts have yielded similar road failures. 3 Results of this study support the current focus on rehabilitation and decommissioning for watershed restoration.
Parent Publication
Citation
Bawcom, Julie A. 2007. Even-Aged Management and Landslide Inventory, Jackson Demonstration State Forest, Mendocino County, California. In: Standiford, Richard B.; Giusti, Gregory A.; Valachovic, Yana; Zielinski, William J.; Furniss, Michael J., technical editors. 2007. Proceedings of the redwood region forest science symposium: What does the future hold? Gen. Tech. Rep. PSW-GTR-194. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; p. 323-334
