Related
Information

Habitat Restoration
Agate Desert Vernal Pool Restoration

Species Fact Sheets
Vernal Pool Fairy Shrimp

Cook's Lomatium

Large-Flowered Woolly Meadowforam

Plant List
Native Vernal Pool Habitat Plant List

Roseburg Field Office
Vernal Pools

Vernal Pools Species Receives Critical Habitat Designation

The U.S. Fish and Wildlife Service has designated approximately 740,000 acres in 30 California counties and one Oregon county as critical habitat for 15 wetland animals and plants listed as threatened or endangered under the Federal Endangered Species Act.

The species included in the August 6, 2003 critical habitat designation are four types of freshwater shrimp – the Conservancy fairy shrimp, longhorn fairy shrimp, vernal pool tadpole shrimp and vernal pool fairy shrimp; and 11 plants that depend on seasonally flooded wetlands known as vernal pools. One species, the vernal pool fairy shrimp, is also found in Jackson county in Oregon.

Typical Vernal Pool

Photo - Vernal pool (USFWS).

Description. Vernal pools are seasonal wetlands that form only in regions where specialized soil and climatic conditions exist. During fall and winter rains typical of Mediterranean climates, water collects in shallow depressions where downward percolation of water is prevented by the presence of a hard pan or clay pan layer (duripan) below the soil surface. Later in the spring when rains decrease and the weather warms, the water evaporates and the pools generally disappear by May. The shallow depressions remain relatively dry until late fall and early winter with the advent of greater precipitation and cooler temperatures.

Photo - Various layers of silicate cements, clay layers, and volcanic bedrock (USFWS).

Specific Adaptations. Vernal pools provide unusual "flood and drought" habitat conditions to which certain plants and animals have specifically adapted. Vernal pools are a prominent feature of the Agate Desert landform, north of Medford, where they are an important link in the food chain for migrating waterfowl, shorebirds, birds of prey, frogs, toads, salamanders and pollinating insects.

Photo - Split view of seasonal phases of a vernal pool (USFWS).

Diminishing Habitat. Only 23 percent of the original vernal pool topography and hydrology in the Agate Desert remains intact. Residential, commercial, and industrial development, along with land leveling, have claimed nearly 60 percent of the historic range of this Agate Desert landform. The remainder of the habitat is either severely altered by historic and continuing land uses, or occurs along the fringes of the landform where vernal pools are weakly expressed.

 

Additional Information:

News release: USFWS Designates Critical Habitat for Threatened and Endangered Vernal Pool Species
(August 2003)

Questions and Answers

Federal Register Notice
(August 2003)

 

 

 

Related Documents

To view Vernal Pool Information Netowrk presentations,
click here.

Programmatic Formal Consultation on USFWS' Vernal Pool Conservation Strategy
Biological Opinion
(January 2011)
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Vernal Pool Study
Temperature and Water Level Dynamics
(April 2009)
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Bryophyte Study Document
Final Report
(September 2008)
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Bryophyte Study Unit Photos
(September 2008)
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Guidance Document

Vernal Pool Assessment and Conservation
(June 2008)

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Final Draft
Vernal Pool Functional Assessment Methodology
[PDF 2.51 MB]
(April 2007)
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Report
Vernal Pool Conservation in the Agate Desert
(October 2006)
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Conservation Strategy
Regional Mitigation & Conservation Strategy

(2006)
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Report
Environmental Characteristics of Vernal Pools
(July 2006)
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Recovery Plan
Draft Recovery Plan for Listed Species of the Rogue Valley Vernal Pool and Illinois Valley Wet Meadow Ecosystems
(June 2006)
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Grazing Report
Effects of Livestock Grazing
(August 2004)
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Fairy Shrimp Survey
Survey on Public Lands
(July 1999)