USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics Water and Watersheds

Study explores stream nitrogen concentrations

For the first time, a collaborative study [] has compared water quality trends in forested streams across the country that are largely undisturbed by land use or land cover changes. The study draws on 559 years of stream nitrate and 523 years of stream ammonium data from 22 streams in 7 experimental forests across the country. The study found that even near-pristine forested streams are subject to change.

Southern Sierra Critical Zone Observatory

The Kings River Experimental Watersheds hosts the Southern Sierra Critical Zone Observatory--a National Science Foundation effort to gain a better understanding of the zone of earth where "rock meets life." The critical zone extends from the tops of the trees to the groundwater and covers the entire earth where there is land. Dowload the video created by a UA Flandrau Science Center team to introduce the motivation and science involved in the National Critical Zone Observatory research program.

Kings River Experimental Watersheds (KREW)

KREW Location: Sierra National Forest

The KREW research project is located on the Sierra National Forest, High Sierra Ranger District, east of Shaver Lake, California. A set of location maps are available here.

KREW Providence stream
KREW is part of the larger Kings River Project (KRP). The KRP is a sustainable forest ecosystem study that allows scientists to examine the response of an array of ecosystem elements to uneven-aged, small group selection and prescribed fire as described in the draft Kings River Administrative Study Landscape Analysis Plan (1995). The intention is to implement these treatments in suitable locations over time and to monitor the response of physical, chemical, and biological features. The KRP is a collaborative effort between the Sierra National Forest and the Pacific Southwest Research Station (PSW), Sierra Nevada Research Center.

The KRP was developed from the consolidation of the Kings River Administrative Study (KRAS) and ongoing PSW research studies. KRAS was established in 1994 by a Preliminary Study Plan and then with a 1995 draft Landscape Analysis Plan jointly developed by the Sierra National Forest and an Interdisciplinary Research and Management Project Proposal by PSW.

The KRP area is large enough (approximately 131,500 acres within the Dinkey Creek and Big Creek watersheds of the Kings River drainage) to allow replication of experiments and represents the heterogeneity of southern Sierra ecosystem types. Research study areas range in size from very localized small plots to small watersheds and landscapes depending on the species or process being studied. Small mammal plots are less than 2 ha (5 acres), forest bird study plots are 40 ha (100 acres), experimental watersheds are 50-100 ha (120-250 acres), and owl study areas are 400 ha (1,000 acres).

KREW Bull forestThe southern Sierra Nevada is a semi-arid, patchy forest landscape with lots of localized soil and vegetation diversity; the KRP is representative of this diversity with several forest types, large outcrops of granite, a steep elevational gradient, and a mosaic of federal and private land ownership. PSW's Teakettle Experimental Forest (1,000 ha or 2,470 acres) shares a southeastern boundary with the KRP and provides a unique opportunity for comparisons between managed forest ecosystems and unmanaged, old-forest ecosystems. Several of the PSW research studies have locations in both the Teakettle Experimental Forest and the KRP. Southern California Edison has substantial lands within the KRP and has been a collaborator since the beginning of the project.

The overall purpose of the KRP is to evaluate the response of forests to a management strategy consisting of a specific uneven-aged silviculture and prescribed fire program. The nature of this program has been defined by the management team from the Sierra National Forest in consultation with scientists at PSW. Several core study components exist: uneven-aged management strategy, experimental watersheds, air quality, birds, fisher, and owls.

One of the KREW control watersheds (T003) is located on the Teakettle Experimental Forest.

Last Modified: Jun 21, 2013 08:30:07 PM