Importance / Issues

Whiskeytown National Recreation Area is the only known location on earth of Puccinellia howellii (Howell's alkali grass, CNPS IB), a perennial short-lived grass, which is an obligate wetland species.  It occurs in a complex of mineral springs which support a rare plant community of considerable importance to wildlife and have been listed by the State of California as a Significant Natural Area (SHA-41).  Water discharges at numerous points within the spring complex, creating sheet flow and channels over much of the wetland.  Sites with perennial ground water discharge support, or have supported, monotypic stands of P. howellii.  Stand densities range from scattered individuals in rocky and gravelly substrates, to more dense stands in water tracks. 

It is believed that a recent roadway realignment may be negatively impacting the site.  The realignment itself created a much larger, deeper, and more extensive cut into the Copley Greenstone bedrock, which is the water-bearing aquifer supporting the springs.  The cut is deep enough that it intersects water-bearing rock, and ground water is likely in contact with the underside of the road pavement.  Subsequently, a new spring formed on the southern road edge, and P. howellii has colonized this new spring. 

Information developed from this project was utilized to inform and support the development of a Conservation Agreement for Puccinellia howelli with participants including the U.S. Fish and Wildlife Service, National Park Service, California Department of Fish and Game, and the California Department of Transportation.

Project Status

Completed. Data from this project has enabled the NPS to partner with Colorado State University and Caltrans in the development of a restoration plan for the mineral springs which supports this species.

Objectives

The first objective was to investigate the hydrogeochemical template of the spring complexes and the impacts of the existing road configuration, as well as future road projects, on P. howellii .

The second objective was to quantify the natural range of water and soil chemical conditions on site to determine whether the road has created distinctly different chemical environments. 

The third objective is to estimate annual sediment flux from the road to the wetland.

Parks

Whiskeytown National Recreation Area

Principal Investigator

David J. Cooper
Senior Research Scientist
Department of Forest, Rangeland and Watershed Stewardship
Colorado State University
Fort Collins, CO 80523