Hans Jenny Pygmy Forest Reserve

The Hans Jenny Pygmy Forest Reserve lies on the oldest and highest of five wave-cut terraces that rise from the chilly waters of the Mendocino County coast. Each terracein this complex "ecological staircase" is approximately 100,000 years older than the one below it and supports a distinct association of soils, microbes, plants, and animals. The uppermost terrace of the reserve affords an opportunity to study two pristine climax communities, Bishop pine forest and pygmy forest, growing on podzolized (nutrient-poor, highly acidic) soils. Underlying this relatively inhospitable soil is a clay hardpan. These harsh growing conditions have stunted much of the vegetation; some mature trees are barely waist-high, with trunks a few centimeters in diameter. The reserve also harbors an understory of unusual evergreen shrubs with many endemic species such as Mendocino cypress and Bolander's pine. This site, which is protected by The Nature Conservancy (TNC), is named for renowned UC Berkeley Professor Emeritus Hans Jenny, a world authority on soil science who spent over half a century studying the inhospitable soils that support this rare, fragile forest.

Selected Research

  • Landscape evolution: The pygmy forest "ecological staircase."
  • Soil studies: Soil development, nutrient cycling, and vegetation-soil relations.

Contact Information
University of California
Berkeley, CA 94720-3110

Mendocino County, 3.2 km (2 mi.) southeast of Mendocino; 241 km (150 mi) north of San Francisco; 3.5-hour drive from Berkeley campus.
Google Map

Limited trail system; walk-in soil pit; no on-site structures or campgrounds.

Plant List
Results from soil surveys

faculty director on campus

28 hectares (70 acres)

180 m (591 ft.)

Average Precipitation
98 cm (39 in.) per year

Average Temperatures
September maximum: 15ºC (59ºF)
January min: 8ºC (47ºF)
Annual mean: 12ºC (53ºF)

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