COMMON CRUPINA MONITORING ON THE ZUMWALT PRAIRIE PRESERVE, 2014

Assessment of the 2013 helicopter herbicide treatment on the noxious weed Common Crupina () in Trail Creek Canyon

Project Status Update – December 2014

Janyne M. Little1

SUMMARY Common crupina (Crupina vulgaris) is an invasive that occurs in the Trail Creek canyon on the Zumwalt Prairie Preserve. Field surveys were conducted in 2014 to assess the outcomes of an herbicide treatment applied in the spring of 2013 by a specially-equipped helicopter, including the collection of data related to crupina abundance and spread. From meandering surveys, 106 crupina occurrences were recorded in 2014 within the 2009 infestation area with the highest densities observed on the lower elevation slopes. Forty common crupina occurrences were recorded outside of the 2009 infestation area with 27 of those occurrences located outside of the helicopter treatment area, indicating that the population is spreading. In addition, the 2014 infestation area, 69 ha, increased in size from the 2009 infestation area by 18 ha. A more thorough survey of the perimeter of all crupina populations may expose additional locations of plant outside of the known infestation areas. Continued ground herbicide application may slow the rate of spread and reduce risk to unaffected areas.

1 Zumwalt Botany Technician, The Nature Conservancy, Northeast Oregon Field Office, 906 S River St., Enterprise, OR 97828 ([email protected]).

Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

INTRODUCTION Common crupina (Crupina vulgaris) is a winter annual from the Mediterranean that was first discovered in Idaho in 1968 (Stickney, 1972). In Wallowa County, crupina is a class “B” noxious weed and is not listed as target species (Wallowa County Weed Board, 2014). However, noxious weeds such as crupina threaten native plant and animal communities and the ecosystems in which they thrive. If uncontrolled, crupina has the potential to form nearly monotypic stands which decreases forage for livestock and wildlife (Washington State Noxious Weed Control Board, 1999). Other detrimental effects of noxious weeds include the modification of soil properties such as erodibility, and alteration of natural fire frequencies and other ecosystem functions (Nichols et al., 2010). Crupina seeds are large and do not disperse readily in the wind but may be transported by ruminants such as deer and cattle (Thill et al., 1986). For more information on the ecology and management of crupina see Jansen et al. (2010).

The Nature Conservancy staff first became aware of the existence of crupina on the Zumwalt Prairie Preserve (ZPP) in 2007. Inventory efforts began in 2008 (Jansen et al., 2008), and a monitoring plan was established in 2009 to measure changes in the abundance of common crupina in the 51 ha area where it is known to occur in Trail Creek canyon (Jansen et al., 2009). In 2009, 119 monitoring plots within the 2009 infestation area were selected and surveyed three consecutive years from 2009-2011 (Jansen et al., 2010; Schmalz and Taylor, 2011). Using a Geographical Information System (GIS,) the 2009 infestation area was created from the outer-most crupina locations recorded from 2007-2009. Surveys conducted in 2011 showed that crupina abundance increased significantly from 2010 after little change in 2009 and 2010. The increase in crupina occurred in the interior of the population and along the outer edge, indicating that the population was becoming denser and was spreading into surrounding areas (Schmalz and Taylor, 2011). The ZPP Weed Management Plan states that the crupina population on Trail Creek will be monitored for five years, with actions taken to confine it to the 2010 extent and eradicate it outside of that area (Nichols et al., 2010).

Because there was evidence that the population was spreading, a helicopter herbicide treatment was conducted in the spring of 2013 in effort to control common crupina, before the five year time period had elapsed. The herbicide Milestone (aminopyralid) was applied at a rate of 6 oz/ac to an approximately 98 ha area that encompassed all but the riparian portion of the population. The riparian portion was hand pulled or treated with herbicide on the ground. An assessment consisting of meandering walking surveys in the spring of 2014 measured the results of the herbicide treatment and evaluated crupina spread. The objectives of the survey were to qualitatively measure the effects of the herbicide treatment as well as search for new populations, primarily on the perimeter and outside of the upslope portion of the treatment area in order to gain information about the rate of spread. This report provides details of how the surveys were performed and a discussion of the findings.

METHODS

STUDY AREA This study was conducted on ZPP (117°39N, 45°32W), a 13,600 ha privately owned conservation area in the northern portion of the Zumwalt Prairie which is located in Wallowa County, northeast Oregon, USA. The preserve consists of both upland plateau with gentle topography referred to as “prairie” and

The Nature Conservancy 2 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014 steep, deeply incised “canyon”. The common crupina populations are located only in the canyon portion of the preserve along Trail Creek canyon (Figure 1). The elevation of the crupina infested area ranges from about 920 m to 1300 m.

The area is comprised of steep slopes, complex topography, and rocky, sparsely vegetated ridges. Native vegetation includes various bunchgrass species within a mosaic of forb and shrub communities. Currently, the higher elevation canyon slopes have higher abundances of native species. Bluebunch wheatgrass (Pseudoroegneria spicata) is the dominant grass, but other native grasses such as Idaho fescue (Festuca idahoensis) and Sandberg’s bluegrass (Poa secunda) also are present. Also dotting the landscape are native forbs such as arrowleaf balsamroot (Balsamorhiza sagittata), lupines (Lupinus spp.) and desert parsleys (Lomatium spp.). Lower regions of canyon slopes are largely dominated by several non-native annual grass species (e.g., Bromus spp. and West African grass (Ventenata dubia) and forbs (e.g., tumble mustard (Sisymbrium altissimum), common bugloss (Anchusa officinalis) and scotch thistle (Onopordum acanthium).

An additional crupina population was discovered in the spring of 2014 just northwest of Winter Place near a spring in Trail Creek Canyon (Figure 2). This population covered approximately 0.17 ha and was hand pulled in the spring of 2014 (Jones, pers. comm.). A smaller population in Church pasture consisting of 4 waypoints (one from 2009 and 3 from 2011) has never been treated.

FIELD SURVEYS Field surveys consisted of meandering walking surveys both inside and along the exterior of the upslope portion of the helicopter treatment area. Surveys were conducted at a time when crupina was in flower and easily detected2. Prior to the surveys, all observers were trained in the identification of the target species. Observers ran tracklogs on a GPS to record their path and also took waypoints of common crupina locations. Because it was not feasible to record the location of every plant seen, waypoints were collected primarily at new crupina locations and in heavily infested areas. Where crupina was sparse, just a single waypoint was recorded to represent a cluster of within approximately 10m of one another. ANALYSIS All data from the meandering surveys was analyzed using a geographic information system (ESRI, 2011). Incidental waypoints collected in 2014 that were within 50 m of incidentals from previous years were eliminated to display newly discovered locations of crupina. Waypoint locations as well as tracklog areas were then summed. A new infestation perimeter using the waypoints collected from 2007-2014 was calculated using the Convex Hull tool from the plug-in XTools Pro 10.1 in ArcGIS. The tool uses an algorithm to create a detailed hull3 from the outermost points in the population.

RESULTS AND DISCUSSION

2 Monitoring took place on June 11th in 2009, June 2nd and 3rd in 2010, June 8th and 9th in 2011, and May 22nd & June 6th in 2014. 3 Detailed hull at 50%.

The Nature Conservancy 3 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

A total of 18.5 km were walked during the meandering survey effectively surveying 7.4 ha4 in and around the helicopter treatment area (Figure 3). Two hundred eight incidental waypoints were recorded from the survey as well as stewardship efforts throughout the season; 40 of these were located outside of the 2009 infestation area, and 27 of these waypoints were also located outside of the helicopter herbicide treatment area (Figure 1), which indicates that the population area is expanding. In addition, the 2014 infestation was calculated to cover a 69 ha area, an increase of 18 ha from the 2009 infestation area5.

The areas where crupina was noted through incidental waypoints to be most abundant were located north of the road at lower elevations where the plant was also found to be abundant in the past (Jansen et al., 2011). As elevation increased, observers reported fewer occurrences of crupina, and the occurrences were generally sparser in abundance. Occurrences found outside of the 2009 infestation area and helicopter treatment area were sparse. The majority of the populations found outside of the helicopter treatment area were single plants or clumps of just several plants rather than the thousands of plants found at lower elevations.

The area treated with herbicide in the fall 2014 is reflective of the waypoints collected from the spring and summer (Figure 4). Of the 27 crupina locations recorded outside of the helicopter treatment area in 2014, eight were untreated in the fall 2014 ground herbicide application. The treatment tracklogs show that there was less coverage at the top of the ridge than in the riparian area and on the slopes south of the road (Figure 4).

MANAGEMENT CONSIDERATIONS Five years after the first assessment of the Trail Creek crupina population, the perimeter of the infestation has expanded. By conducting extensive surveys of the perimeter of each crupina population, new plant occurrences may be discovered, which can help direct future weed management decisions. Control measures such as ground herbicide application along the perimeter of the 2014 infestation area may continue to slow the rate of spread and reduce risk to unaffected areas. Revisiting the monitoring sites established in 2009 and collecting more data is required to determine if the helicopter treatment had a significant impact on the crupina population in Trail Creek canyon.

ACKNOWLEGEMENTS Many thanks to Peter Morley and Cameron Hancock for assistance in the field.

REFERENCES ESRI 2011. ArcGIS Desktop: Release 10. Redlands, CA: Environmental Systems Research Institute.

4 This area is based on the assumption that an observer could detect crupina plants within 2m on each side of his/her location. 5 It is unknown exactly how the 2009 infestation area was calculated, but if the methodology used to calculate the 2014 area is applied, the 2009 area (55 ha) is approximately the same at the original (51 ha). The 2011 infestation area is very similar to the 2009 area (56 ha) using the same tool in ArcGIS.

The Nature Conservancy 4 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

Jansen, V. S. and R. V. Taylor. 2008. Initial Inventory of Crupina vulgaris (common crupina) in Trail Creek Canyon, Zumwalt Prairie Preserve. Enterprise, OR, The Nature Conservancy.

Jansen, V.S., Dingeldein, J., Shirley, L., and Taylor, R. V. 2009. Monitoring Common Crupina (Crupina vulgaris) In Trail Creek Canyon on the Zumwalt Prairie Preserve, Wallowa County, Oregon. Unpublished Report. The Nature Conservancy, Northeast Oregon Field Office, Enterprise, OR.

Jansen, V.S., Dingeldein, J., and Taylor, R. V. 2010. Monitoring Common Crupina (Crupina vulgaris) in Trail Creek Canyon on the Zumwalt Prairie Preserve in Wallowa County, OR. Unpublished Report. The Nature Conservancy, Northeast Oregon Field Office, Enterprise, OR.

Nichols, L.J., Jansen, V.S., and Fields, J. 2010. Weed Management Plan. Zumwalt Prairie and Clear Lake Ridge Preserves, Wallowa County, OR. Unpublished Document. The Nature Conservancy, Northeast Oregon Field Office, Enterprise, OR.

Schmalz, H. J. and R. V. Taylor 2011. Common Crupina Increased in Abundance on Trail Creek of the Zumwalt Prairie Preserve from 2009-2011. Enterprise, OR, The Nature Conservancy.

Stickney, P.F. 1972. Crupina vulgaris (Compositae: ), new to Idaho and . Madrono 21:402.

Thill, D.C., D.L. Zamora, and D.L. Kambitsch. 1986. The germination and viability of excreted common crupina (Crupina vulgaris) achenes. Weed Science 34:237-241.

Wallowa County Weed Board. 2014. Class B Listed Noxious Weeds of Wallowa County. Enterprise, OR: Wallowa County Weed Board

Washington State Noxious Weed Control Board. 1999. Common crupina (Crupina vulgaris Cass). Kent, WA.

The Nature Conservancy 5 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

FIGURES

Figure 1. Map of 2009 and 2014 common crupina infestation areas, helicopter treatment area, and incidental waypoints from 2007-2014. 2014 incidentals within 10 m of incidentals from previous years were eliminated to show new locations of crupina found, especially on the outer, upslope edge of the infestation. Few waypoints from 2007-2011 fall far outside of the 2009 infestation perimeter, indicating that the 2011 infestation area was very similar to the 2009 infestation area.

The Nature Conservancy 6 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

Figure 2. Map of all locations of common crupina recorded from 2007-2014.

The Nature Conservancy 7 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

Figure 3. Map of walking survey tracklogs.

The Nature Conservancy 8 NE OR Field Office Zumwalt Prairie Preserve Common Crupina Monitoring, 2014

Figure 4. Map of crupina treatment areas and untreated incidentals. The green points represent locations of crupina discovered in 2014 that were not covered by the 2013 helicopter treatment, assuming the plants were there in 2013. The purple 2014 ground treatment polygon was created by buffering treatment tracklogs by 7m on either side.

The Nature Conservancy 9 NE OR Field Office