The Caspar Creek Experimental Watersheds are the site of a long-term paired watershed study in the northern Coast Ranges of California. The watersheds are predominately forested with coast redwood and Douglas-fir. Old-growth forest was logged between 1860 and 1904. Two harvesting experiments have been completed since then and a third experiment is currently underway. Caspar Creek data are split into three phases corresponding to three experiments: Phase 1 (1962–1985) reports on a selection harvest (1971–1973) and initial recovery in the South Fork watershed; Phase 2 (1985–2017) includes clearcut harvesting of ~50% of the North Fork watershed (1985–1992) and recovery; and Phase 3 (2017 onward) corresponds to a second selection harvest in the South Fork watershed with a range of subwatershed harvest intensities (2017–2019) and recovery. All three experiments included harvest-related road-building and relied primarily on measurements of streamflow and sediment delivery from both treated and reference watersheds. Major findings include modest increases in post-harvest peak flows and cumulative flow volumes, post-harvest low flows that initially increased and then decreased 12 to 15 years after harvesting, and the consequences of different yarding techniques and road design on sediment yields. Some of the data for Phase 1 and Phase 2 are available in a USDA Forest Service online archive. The archived data include precipitation, streamflow, suspended sediment concentrations, turbidity, accumulated weir pond sediment volumes, bedload transport rates, water stable isotope data, and geospatial data. Archiving activities are ongoing. Phase 3 data are currently being collected and will be archived after a post-harvest monitoring period.
Bibliographical noteFunding Information:
This project is funded by the USDA Forest Service Pacific Southwest Research Station and the California Department of Forestry and Fire Protection (CAL FIRE). Funding for the water stable isotopes was provided by the National Science Foundation (Grant # NSF‐EAR‐1807165). The Caspar Creek Experimental Watersheds are primarily located within the Jackson Demonstration State Forest, which is owned by the state of California and maintained by CAL FIRE. In addition, the SFC watershed includes approximately 6 ha of private property and approximately 5 ha that are located in the Russian Gulch State Park. Over the 58‐year history of the Caspar Creek Experimental Watersheds, hundreds of scientists, students, and volunteers have contributed to the collection, processing, and analysis of data.
We thank Pete Cafferata, Lynn Webb, Drew Coe, the staff of the Jackson Demonstration State Forest, and CAL FIRE for their continued support and investment in the Caspar Creek Experimental Watersheds. We also thank the dedicated USDA Forest Service personnel responsible for the collection, processing, and maintenance of Caspar Creek data.
© 2021 John Wiley & Sons Ltd. This article is a U.S. Government work and is in the public domain in the USA
- Caspar Creek
- experimental watersheds
- paired watersheds
- timber harvest