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Pacific Southwest Research Station
Pacific Southwest
Research Station

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Renewing and refining the Tahoe yellow cress Conservation Strategy: incorporating new science and management tools

Proposal [pdf]

Lead Researchers:

Alison Stanton, Consultant
Bruce Pavlik, Royal Botanic Gardens Kew


Tahoe yellow cress (TYC) will always be a rare plant because it occurs only on the shores of a single lake, Lake Tahoe. The degree of endangerment to the species in this high profile habitat depends on a host of factors, many of which can be managed on some level. Since the adoption of the Tahoe yellow cress Conservation Strategy (CS) in 2002, the Adaptive Management Working Group (AMWG) has worked together to address threats to Tahoe yellow cress and coordinate efforts to manage and protect the species. A central emphasis has been the implementation of a field-based research program conducted between 2003 and 2010 testing the role of genetic, hydrologic, and logistical factors in population restoration using container-grown Tahoe yellow cress plants. Yearly analyses have been conducted and most recently we have tested the effectiveness of translocation (moving naturally occurring plants from one site to another). We propose to 1) conduct a synthesis and meta-analysis of this existing dataset (2003-2010); and 2) incorporate resulting protocols for outplanting and translocation into a series of new management tools in the CS for restoration and mitigation. We further propose to utilize the existing survey record from 1979-2011 to 3) update the conceptual model of TYC population dynamics; 4) valuate and update indicators in the CS, and 5) develop a geo-database for data management and analysis. The Memorandum of Understanding uniting 13 signatories in the cause to implement the CS is set to expire on January 29, 2013, ten years after the last signature date. The main consequence of failure of the signatories to continue to implement the CS is reconsideration by the U.S. Fish and Wildlife Service (USFWS) to list the species under the Endangered Species Act. Federal listing would significantly increase the regulatory burden on all projects located in or near the shorezone around Lake Tahoe. In response to the apparent success of the CS, recent regional planning efforts are specifically referencing the strategy in sensitive species sections that address Tahoe yellow cress. From a regulatory standpoint agencies will be relying on continued implementation of an updated CS that incorporates new science and management tools.

Relation to Other Research Including SNPLMA Science Projects

The proposed research to update the conceptual model of Tahoe yellow cress population dynamics and the associated indicators (Priority ranking index and Minimum Viable Population size) leverages the presence/ absence and stem count data from the annual surveys and builds upon analytical methods developed in the CS (Pavlik et al., 2002). Likewise, the majority of the data needed to populate the proposed ARC database is already contained in annual survey reports or can be mined from the Nevada Natural Heritage Program Biotics database.  The experimental field plantings of container-grown Tahoe yellow cress plants was initiated because of the documented success of greenhouse propagation and plantings by Western Botanical Services (Etra, 1994). The synthesis and analyses proposed here leverage the large dataset generated by pilot and experimental plantings conducted from 2003 to 2009.

Expected date of final products:

December 2014

Last Modified: Nov 12, 2014 03:44:52 PM