Sagebrush steppe vegetation monitoring in Craters of the Moon National Monument and Preserve, Hagerman Fossil Beds National Monument, John Day Fossil Beds National Monument, and Lake Roosevelt National Recreation Area: 2009 annual report

Rodhouse, Thomas

As part of the Upper Columbia Basin Network’s (UCBN) effort to conduct vital signs monitoring in 2009, key indicators of sagebrush steppe vegetation biotic integrity, soil stability, and hydrologic function were measured in Craters of the Moon National Monument and Preserve (CRMO), Hagerman Fossil Beds National Monument (HAFO), John Day Fossil Beds National Monument (JODA), and Lake Roosevelt National Recreation Area (LARO). Sagebrush steppe is one of the most threatened ecosystems in the intermountain west, and land use practices both within and adjacent to UCBN park steppe communities have resulted in fragmented and altered park ecosystems. Predicted climate change for the region may exacerbate these changes. This annual report summarizes key indicators of rangeland health obtained from the first pilot season of monitoring in CRMO and LARO, and the second pilot season of monitoring in HAFO and JODA. Methods followed a draft protocol that had been peer-reviewed and was in revision at the time of data collection. A final, peer-reviewed and approved protocol was produced following the 2009 field season, which will be implemented in 2010. Changes between the draft and final protocol were inconsequential to methods and analyses conducted for this report and the data used for this report will be included in subsequent trend analyses. Cover of principal native and non-native plant species and bare ground was estimated in 1244 plots distributed across the 4 parks in multiple discrete sampling “frames”. Sample plot locations were drawn using a spatially-balanced random sampling design, the Generalized Random Tessellation Stratified (GRTS) design, which ensures a good representative random sample with good dispersion within each sampling frame. Analyses of 2009 data included here describe baseline conditions of sagebrush steppe community composition and structure against which future change will be measured. In general, the results from 2009 provide consistent and biologically interpretable descriptions of existing conditions (status) of park frames. Areas in good condition have higher amounts of native vegetation and fewer non-native species, as expected. However, a wide range of conditions were encountered among and within parks. The proportion of plots containing cheatgrass (Bromus tectorum), a ubiquitous invasive annual grass introduced from Eurasia during the 19th century, ranged from 4% in one CRMO frame, to 100% in several frames in HAFO, JODA, and LARO. The proportion of plots with cheatgrass cover greater than 25% ranged among frames from 2%-89%. Bluebunch wheatgrass (Pseudoroegneria spicata), a fundamental native perennial bunchgrass species included in potential natural vegetation descriptions for all 4 parks, was not encountered in any sample plot in HAFO. The proportion of plots in the other parks in which this species occurred with greater than 5% cover ranged from 2%-73%. The proportion of plots containing greater than 5% cover of big sagebrush (Artemisia tridentata) ranged from 0% in one frame in LARO to 70% in CRMO. Noxious weeds were encountered rarely within plots (less than 4%), and only in areas with highest historic disturbance and that were also covered with large amounts of cheatgrass and other non-native species. Tumbling mustard (Sisymbrium altissimum), a Eurasian annual forb indicative of rangeland degradation, occurred with greater than 5% cover in 4-15% of plots in HAFO. Each of these parks occurs in very different environmental settings. Elevations, soil types, and land use histories differ widely among the 4 parks and differences in status are not readily comparable. Rather, each park needs to be considered within its own unique biophysical context, and, accordingly, this report presents results by park in a graphical format.

Sagebrush steppe vegetation monitoring in Craters of the Moon National Monument and Preserve, Hagerman Fossil Beds National Monument, John Day Fossil Beds National Monument, and Lake Roosevelt National Recreation Area: 2009 annual report

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