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U.S. Forest Service


California Fens

Hotspots of Biodiversity

Fens are an important and unique wetland type. Fens are peat-forming wetlands that rely on groundwater, require thousands of years to develop, and cannot easily be restored if destroyed. They are home to rare plants, insects, small mammals, and large animals. They are sites of groundwater discharge, nutrient recycling, erosion traps, and pollution filters.

Fen in the Butterfly Valley in spring, Plumas National Forest.

What is a Fen?

Fens are hotspots of biodiversity.

Basin fen graphic.

Types of Fens

How do groundwater and topography conspire to create a fen?

Hanging Fen in the Convict Creek Basin, California.

Rich Fens, Poor Fens

Water chemistry and bedrock influence fen species diversity.

Fen in Upper Sagehen Basin, Tahoe National Forest.

How Old are Fens?

Aging our California fens.

Inglenook Fen..

Diversity of Fens

How diverse are our California fens?

American River Ranger District employees and the Green Corp raking in vehicle wheel ruts in the Tadpole fen.

Fen Conservation

What are we doing to conserve fens on the National Forests in California?.

Paired exclosure monitoring on the Beckwourth Ranger District.

Fen Monitoring

Monitoring is designed to assist the management and restoration of fen wetland ecosystems.

Dick Brainerd and Martin Lenz, Crow Creek Fen, Shasta-Trinity National Forests.

More Information

Resources and citations of more information about ferns.

https://www.fs.usda.gov/wildflowers/beauty/California_Fens/index.shtml