Cooperative Agreement for CESU-affiliated Partner with USGS Rocky Mountain Cooperative Ecosystem Studies Unit

Funding Opportunity Description (“Long-term monitoring of riparian vegetation response to biological control of Tamarix along the lower Virgin River”)

The U.S. Geological Survey (USGS) Fort Collins Science Center (FORT), is offering a funding opportunity to a CESU partner for conducting management, presentation, analysis and interpretation of results related to a long-term monitoring dataset examining responses of riparian vegetation to biological control of the invasive shrub, tamarisk (genus Tamarix) along the Virgin River in Nevada and Arizona. Controlling invasive shrubs in the genus Tamarix (tamarisk, saltcedar) is one of the main goals of resource managers along western U.S. rivers, including DOI agencies such as NPS, BLM, and FWS. Ecosystem responses to tamarisk defoliation are variable, and there is concern about when, where, and why unintended consequences, such as secondary plant invasions, degraded wildlife habitat, or extreme fire hazards, may develop. Land managers seek guidance on how to mitigate these undesirable effects and restore native riparian vegetation. Understanding long-term vegetation dynamics following tamarisk biocontrol can significantly help resource managers assess the need for future management interventions, but to date, most studies of tamarisk biocontrol have only included one to a few years of monitoring. This project will expand knowledge of long-term riparian vegetation response to tamarisk biocontrol along the lower Virgin River, where significant effects of defoliation began in summer 2012. During four different surveys over eight years (2010, 2012, 2015 and 2017), the USGS has made repeated observations of plant composition and cross-sectional topography along the Lower Virgin extending from Littlefield, AZ to Lake Mead, and will be resampling these study transects in the spring of 2021.

Through this CESU agreement, the federal and state university partners will cooperate fully in development of a research program that will produce final products to provide resource managers with better information on which to base decisions regarding riparian vegetation response to tamarisk biocontrol. Cooperation between the USGS and its CESU partner brings a combination of expertise to address this objective that is greater than that possessed by either partner on its own.

Research Objectives:

The overarching objective of the opportunity is to foster collaborative and cooperative research between FORT and CESU scientists on the analysis of a long-term vegetation change dataset from the Virgin River. FORT will be primarily responsible for providing multi-year datasets of plant community composition and topographic change along 24 transects in five river reaches of the Virgin River, and CESU scientists for data analysis and interpretation and report preparation, though both entities will cooperate on the data analysis, interpretation, and writing pieces. FORT scientists’ bring decades of riparian field ecology expertise and applications to Department of the Interior resource management issues, and CESU scientists have proven abilities to compile and analyze tamarisk control datasets, scientific literature and technical reports and knowledge specific to Tamarix control management practices in western United States. CESU and FORT scientists will work together to ensure that all data analyses, associated figures and tables are rigorous and appropriate for subsequent publication in peer-reviewed journals and USGS publications (e.g., Data Releases; final publications are not part of this agreement, however). This is a discrete body of work that is anticipated to be completed over the course of one year, though due to the potential for coronavirus pandemic-related delays, two years is permitted.

Specific objectives of this work are to:

1) Compile, QA/QC and prepare a database and associated metadata for riparian vegetation and topographic data collected in 2021 on the Virgin River.

2) Examine long-term vegetation dynamics by examining time-series of plant composition and topographic survey datasets. Examine plant composition data using multivariate and other statistical techniques.

3) Prepare visual, tabular, and written summaries of the methods, results, data, and associated analyses.

4) Cooperate and collaborate with USGS scientists in the drafting of information products such as articles for peer-reviewed journals and USGS data releases.

The anticipated benefits of the project are to enable resource managers to 1) better understand the dynamics of plant communities that replace tamarisk following biological control, and thereby -- 2) anticipate changes to aspects of vegetation that underpin key resource management concerns such as exotic species invasions, wildlife habitat quality, and fire hazard, which can inform 3) management interventions such as invasive species control, native plant revegetation, or fire mitigation activities.