Upper Verde River: Review of Stream-Riparian Monitoring Efforts Conducted by the U.S. Forest Service Rocky Mountain Research Station

Dwire, Kate; Buffington, John; Merritt, David; Rieman, Bruce; Tait, Cynthia

The Verde River, one of Arizona’s major perennial rivers, is critical for local and regional biodiversity. It provides aquatic habitat for native fish and amphibian species, including several federally listed fish species, and riparian habitat for bird species (many Neotropical migrants) and a host of other vertebrates such as river otter, beaver, and herpetofauna. Much of the Verde River corridor is managed by the USDA Forest Service. Given its ecological value and increasingly high profile, the Forest Service must have full confidence in monitoring and research data collected on the Verde River, especially data that may be used to inform management decisions. Since 1994, Rocky Mountain Research Station (RMRS) personnel have collected monitoring data on the Upper Verde River, in collaboration with the Prescott National Forest. The overall goal of this monitoring was to describe and characterize temporal changes in riparian vegetation, physical channel features, and fish assemblages in the Upper Verde River. During the week of April 7-11, 2008, a review of RMRS research and monitoring efforts on the Upper Verde River was conducted. The review consisted of presentations, followed by field tours to different sampling locations along the Upper Verde River including portions of the river accessible only by train. Published information and data were available principally for stream flow and fish-related work. During the review, few data were available to the review team, limiting our ability to assess what RMRS has contributed to current understanding of the Upper Verde River. Preliminary results and analyses addressing interactions between vegetation, geomorphology, and fish populations were discussed. Some portion of the monitoring results will be presented in a forthcoming General Technical Report (GTR). We interpreted the observations from monitoring efforts by RMRS researchers and colleagues on the Prescott National Forest as hypotheses, responding to them as peer reviewers, while recognizing that the interpretations have not been formally stated or tested. In addition, we provided our professional perspective on the hypotheses/interpretations with ideas on how they may be more rigorously examined. Presentations and field discussions of the monitoring data collected by RMRS personnel to date on the Upper Verde River led to concerns regarding limitations of monitoring efforts for interpreting riparian vegetation and geomorphic conditions. From an agency perspective, we believe that it is critical to emphasize that the limitations of the data must be clearly acknowledged, and that these monitoring data probably cannot be used to conclude cause-and-effect relationships or to justify management decisions. Indeed, RMRS personnel indicated that (due to lack of resources) the vegetation and geomorphic data were not collected to test hypotheses or to make cause-and-effect linkages. Until existing data are analyzed, peer-reviewed, and published, the statements and hypotheses regarding vegetative changes, trends, interactions with management activities, and linkages to fish habitat, physical characteristics and processes remain unsupported. Furthermore, lack of repeat sampling at fixed locations limits the power of the vegetation data for monitoring purposes and for evaluation of treatment effects, such as land use or natural disturbance. Despite these concerns, the collected data may be of considerable value. A recent report by The Nature Conservancy (Haney et al. 2008) notes the paucity of data available for the Upper Verde River. Following review and publication, the information derived from RMRS monitoring efforts could potentially contribute to discussions regarding future management directions by USFS and increased collaboration among the full range of Upper Verde River stakeholders.

Upper Verde River: Review of Stream-Riparian Monitoring Efforts Conducted by the U.S. Forest Service Rocky Mountain Research Station

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