Declines in cold water habitat and fisheries have generated stream temperature monitoring efforts across northern California and the western United States. In this paper we demonstrate a statistical analysis approach to facilitate the interpretation and application of these datasets to achieve monitoring objectives. Specifically we demonstrate an approach to identify and quantify relationships which might exist between stream temperature and factors such as streamflow, stream canopy cover, and air temperature.
Watershed groups, individuals, and land management and regulatory agencies are collecting stream-temperature data in order to understand, protect and enhance cold-water fisheries. While great quantities of data are being generated, its analysis and interpretation are often not adequate to identify stream reaches that are gaining or losing temperature, or to correlate temperature changes with factors such as vegetative canopy cover or stream-flow levels. We use a case study from the Lassen and Willow creek watersheds in northeastern Modoc County to demonstrate graphical methods for displaying, analyzing and interpreting stream-temperature data.
Standards for the height of herbaceous vegetation remaining in meadows at the end of the growing season have been, and continue to be, implemented on public grazing lands throughout the Sierra Nevada. Although supporting research is limited, stubble height standards are intended to benefit riparian resources by limiting grazing pressure. This study illustrates how the timing and intensity of defoliation in mountain meadows can affect the stubble height of herbaceous vegetation at the end of the growing season, and compares these findings with current standards. The research also can help livestock operators and public lands managers develop grazing management strategies to meet stubble height standards and conduct local applied research to evaluate the appropriateness of general stubble height standards.
Northern California has extensive areas of irrigated pasture, which provide critical summer forage for livestock. In many of these systems, water is diverted directly from a stream into ditches or pipes and transported to individual pastures, where it is applied as flood surface irrigation. Our case study of discharges from irrigated pastures on Willow and Lassen creeks in Modoc County illustrates an assessment and monitoring approach for land managers and natural-resources professionals working to resolve water-quality impairments related to agricultural discharges from similar systems. We report correlations between four indicator variables measured in the field and the variables determined in the laboratory, to evaluate the potential for employing a strategic combination of the two.
Declines in cold-water habitat and fisheries have generated stream-?temperature monitoring efforts across Northern California and the western United States. We demonstrate a statistical analysis approach to facilitate the interpretation and application of these data sets to achieve monitoring objectives. Specifically, we used data collected from the Willow and Lassen creek watersheds in Modoc County to demonstrate a method for identifying and quantifying potential relationships between stream temperature and factors such as stream flow, canopy cover and air temperature. Our monitoring data clearly indicated that a combination of management practices to increase both in-stream flow and canopy cover can be expected to reduce stream temperature on the watersheds studied.
Watershed groups, individuals, and land management and regulatory agencies are collecting stream temperature data to understand specific stream systems in an effort to protect and enhance cold-water fisheries. While great quantities of stream temperature data are generated, data analysis and interpretation is often not adequate to identify stream reaches which are gaining/losing temperature, or to correlate stream temperature changes to factors such as vegetative canopy cover or streamflow levels. We use a case study to demonstrate graphical methods to display and interpret stream temperature data for this purpose.