Monitoring sagebrush-steppe vegetation in the Upper Columbia Basin Network: 2008 annual monitoring report for City of Rocks National Reserve, Hagerman Fossil Beds National Monument, and John Day Fossil Beds National Monument.

Rodhouse, Thomas

The Upper Columbia Basin Network of the National Park Service has identified 14 priority park vital signs, indicators of ecosystem health, which represent a broad suite of ecological phenomena operating across multiple temporal and spatial scales. Our intent has been to monitor a balanced and integrated “package” of vital signs that meets the needs of current park management, but will also be able to accommodate unanticipated environmental conditions in the future. Sagebrush steppe is one particularly high priority vital sign for five UCBN parks: City of Rocks National Reserve (CIRO), 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 occupies over 50% of land cover in CIRO, HAFO, and JODA, and over 90% of the vegetated area of CRMO. At LARO, sagebrush steppe is present and significant in the southern half of the park and represents an important park ecosystem. Historic and current land use practices both within and adjacent to UCBN park steppe communities continue to fragment and alter steppe ecosystems, and predicted climate change scenarios for the region will likely exacerbate these changes. This annual report details the status of key indicators of rangeland health obtained from the first season of monitoring in CIRO, HAFO, and JODA, 2008. This season was considered a pilot year, and the UCBN tested a draft protocol that was submitted for peer review in spring 2008. A number of protocol revisions are forthcoming, and will not be detailed here. Over 500 plots were measured across the three parks in 2008. These results clarify the unique community types that occur in each park, ranging from the bunchgrass-dominated steppe at JODA to the dense mountain big sagebrush stands in CIRO. Describing the composition and structure of these communities is a critical first step for managers in understanding their respective park systems, setting desired future conditions, and interpreting future trends. For example, cheatgrass (Bromus tectorum) and other annual invasive grasses dominate many areas of HAFO and JODA, two low-elevation parks. At CIRO, a high-elevation park, cheatgrass is widely present but represents only a small fraction of overall plant cover. Identifying trends in cheatgrass invasion at CIRO will be a high priority for that park, given the potential shifts in precipitation predicted under future climate change scenarios. Likewise, in the low-elevation parks where cheatgrass is so ubiquitous, concern may instead be directed towards emerging threats such as invasion by the annual grass medusahead (Taeniatherum caput-medusae) in JODA, or loss of perennial bunchgrasses in HAFO. Differences in cover indicators were also detected among some of the grazing allotments in CIRO, illustrating the important feedback for grazing programs at CIRO and LARO that this monitoring effort can provide in the future.

Monitoring sagebrush-steppe vegetation in the Upper Columbia Basin Network: 2008 annual monitoring report for City of Rocks National Reserve, Hagerman Fossil Beds National Monument, and John Day Fossil Beds National Monument.

Series

Collections