Sagebrush steppe vegetation monitoring in the Blue Basin Area of the John Day Fossil Beds National Monument: 2018 annual report

Nicolli, Melissa

As part of the Upper Columbia Basin Network (UCBN) sagebrush steppe vital signs monitoring program, the ecological condition of the sagebrush steppe within the Blue Basin Area of the Sheep Rock Unit of John Day Fossil Beds National Monument (JODA) was surveyed in late May of 2018. The surveys were conducted following methods outlined in the UCBN sagebrush steppe monitoring protocol (Yeo et al. 2009). The cover of exposed soil and the above-ground foliar cover of principal native and non-native plants or genera were estimated in one-hundred fifty-one 1 m2 quadrats randomly placed throughout the sampling frame (Figure 1). This portion of the Monument was first surveyed in 2011 and has since been surveyed in 2014, 2016, 2017, and 2018. These recent annual survey efforts beginning in 2016 were outside of the UCBN’s 3-year revisit plan, in response to the 2015 wildfire that swept through the Blue Basin area. The Blue Basin fire burned 266 acres within the Blue Basin unit and came within 25 feet of burning down a historic homestead at the Blue Basin recreation site. The Sugarloaf fire burned 48 acres within the Blue Basin unit at the same time as the Blue Basin fire. The two are considered part of the same fire complex, collectively burning almost 315 acres within the Blue Basin unit. The entire monument, including the Blue Basin Unit, was surveyed during June-July, 2014, as part of the Network’s regular 3-year revisit schedule (Yeo and Rodhouse 2012). This provided an excellent opportunity to study the impact the fire had on Blue Basin. This report describes the findings from 2018, and creates comparisons among key species of interest to the 2011-2017 observations. It also makes some post fire recovery comparisons to the Clarno unit of JODA, which burned in 2011 and which has been monitored annually 2012-2017 to also examine post-fire recovery. This report provides some insights into the effects of fire and the increasing invasion of non-native plants in JODA’s upland plant communities, a topic of critical importance to park management. Cheatgrass (Bromus tectorum) amd medusahead (Elymus caput-medusae) species continue to dominate much of the Blue Basin landscape, presenting a major threat to the ecological integrity of the unit. In addition to these two invasive dangers, a fairly recent newcomer, wiregrass (Ventenata dubia) has been seen in larger numbers over the past few years and is a species of concern that could easily take over an already compromised landscape. Big sagebrush (Artemisia tridentata) was found in only 2.7% of plots surveyed in 2018 (n=151), and many areas that once supported sagebrush have remained shrub cover free since the 2015 wildfire. The cover of native bunchgrasses, which is an integral part of a healthy sagebrush steppe, has remained at low to moderate cover. Principal native bunchgrasses that were surveyed include: bluebunch wheatgrass (Pseudoroegneria spicata), Sandberg bluegrass (Poa secunda), needlegrasses (Achnatherum spp.), and sand dropseed (Sporobolus cryptandrus). Bluebunch wheatgrass, a foundation species in the Blue Basin landscape, has remained constant with initial post fire conditions, being in ~ 40% of plots surveyed. This number is actually an increase compared to pre-fire percentages, but the early surveys in 2011 and 2014 had low sample sizes (because the Blue Basin area was included in the sample size draw for the entire Sheep Rock East frame, not given special stratification focus as was done after the fire), making the numbers less representative of a whole landscape. Overall, native species appear to have recovered relatively well from the fire, with plot cover levels in 2018 comparable to those prior to the fire. Native forb cover remains low. Principal native forb species included: milk-vetch (Astragalus spp.), yarrow (Achillea millefolium), buckwheats (Eriogonum spp.), Blue Mountain prairie clover (Dalea ornata) and desert parsley (Lomatium spp.). Yarrow was the most.........

Sagebrush steppe vegetation monitoring in the Blue Basin Area of the John Day Fossil Beds National Monument: 2018 annual report

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