Viola selkirkii (Selkirk s violet) Survey Report for the Pike and San Isabel National Forests Performed in June, 2010

Transcription

1 Viola selkirkii (Selkirk s violet) Survey Report for the Pike and San Isabel National Forests Performed in June, 2010 Closeup of Selkirk s violet in bloom. The diagnostic glassy hairs on the leaves are easily visible. Brian Elliott and Scott Smith 1 July 2010 Contact Information: Brian A. Elliott brianelliott.eec@gmail.com elliottconsultingusa.com Scott F. Smith Scottsmithservices@gmail.com Steve Olson solson01@fs.fed.us

2 Table of Contents Introduction... 3 Background... 3 Identification of Viola selkirkii... 3 Methods... 4 Results... 4 Newlin Creek... 4 Photo 1: Newlin Creek Habitat... 6 Photo 2: Viola selkirkii from Newlin Creek... 7 Map 1: Newlin Creek Survey Routes Map 2: Newlin Creek points... 8 Hayden Creek... 9 Map 3: Hayden Creek Survey Routes... 9 Montgomery Reservoir Photo 3: Habitat at Lincoln Ice Falls Photo 4: Viola selkirkii near Lincoln Ice Falls Map 4: Survey Routes and Viola Site at Lincoln Ice Falls Tappan Gulch near Platte Springs Photo 5: Habitat at Tappan Gulch Map 5: Survey Routes Near Tappan Gulch Platte Springs Map 6: Survey Route at Platte Springs Devils Head Photo 6: Habitat at Devil s Head site Photo 7: Devil s Head habitat Map 7: Devil s Head site South Gerber Creek and Bear Creek Map 8: Gerber Creek Map 9: Bear Creek Pine Creek Map 10: Pine Creek Summary Other Botanical Discoveries Map 11: Diffuse knapweed at Gerber Creek Map 12: Diffuse knapweed above Pine Creek Photo 8: Aquilegia saximontana at Tappan Gulch Map 13: Aquilegia saximontana at Tappan Gulch Literature Cited... 25

3 Introduction Directed surveys for Selkirk violet were performed by Brian Elliott and Scott Smith on the Pike and San Isabel National Forests from June 15 through June 18, Every reported site on both the Pike and San Isabel National Forests was visited to assess presence or absence of the rare violet as well as habitat type and conditions. Additional surveys were performed in likely habitats where no Viola selkirkii had been previously reported. Of the six reported sites on the Pike and San Isabel National Forests the violet was located at only two sites. No additional populations were found during surveys of other likely habitat. Background Viola selkirkii inhabits cold mountain aspen forests, moist woods, and thickets. Flowers are produced in May and June. The species ranges from Alaska and Canada to the upper Midwest, northeast, and Washington with disjunct populations known from Colorado and reported from New Mexico. Although the plant has been reported from New Mexico (Harrington 1954, Hornbeck, Sieg, and Reyher 2003, and Martin and Hutchinson 1984), no vouchers could be located. Martin and Hutchinson (1984) state that the species can be expected from Rio Arriba and Taos counties of northern New Mexico. In Colorado, this violet has been reported from eight areas: Rocky Mountain National Park. Near Nederland on the Roosevelt National Forest. The base of Devil s Head in the Rampart Range on the Pike National Forest. Newlin Creek in the Wet Mountains on the San Isabel National Forest. Near Lincoln Ice Falls above Montgomery Reservoir on the Pike National Forest. Tappan Gulch near Platte Springs. This site was reported by Sheila Lamb. South Gerber Creek along the Rampart Ridge Road on the Pike National Forest. This site was reported by contract botanists to Denny Bohon. Bear Creek near the Rampart Ridge Road on the Pike National Forest. This site was reported by contract botanists to Denny Bohon. The species is considered secure globally, although there is some uncertainty about the ranking (G5?). In Colorado it is critically imperiled and receives a rank of S1. Six of the eight known sites in Colorado are reported from the Pike or San Isabel National Forests. Unfortunately, no photographs or voucher specimens are known from three of the reported sites. Identification of Viola selkirkii Viola selkirkii is easily identified by the large hairs on the upper leaf surface that can be seen without magnification. These hairs are glassy, broad at the base, and semi-erect to erect (although the hairs are appressed on pressed specimens). When light strikes a leaf at an appropriate angle these hairs reflect the light and appear to shine. Viola adunca

4 may be confused with Viola selkirkii as a result of pubescence on the upper leaf surface. These hairs, however, are quite different from the hairs found on Viola selkirkii. Pubescence on the leaves of Viola adunca and Viola sororia is very short and stiff. This pubescence may cause botanists unfamiliar with the unusual leaf hairs of Viola selkirkii to misidentify these violets as Viola selkirkii, particularly when plants are vegetative. Purple flowers, a large spur, and leaves with deep sinuses are also important morphological characteristics in identification of Viola selkirkii. The spur on Viola selkirkii is nearly as long as the petals and the end of the spur is round and enlarged. This large spur gives the species one of its common names, the great spurred violet. Viola selkirkii has a reputation of being the first violet to bloom in the spring; this reputation is undeserved. Several other violets, including V. adunca, V. canadensis, V. labradorica, V. nuttallii, V. renifolia, and V. sororia, may bloom as early or even earlier than Viola selkirkii. Methods Each reported site on the Pike and San Isabel National Forests was visited to document the locality and habitat characteristics. These reference sites visits served to verify the presence or absence of the species at reported sites by either photographs or voucher specimens, to inform surveyors on the phenology of the plant, and to focus additional surveys in appropriate habitats. Additional surveys were performed using an intuitivecontrolled method in which surveys are focused on areas of high-probability habitat. Results Nine sites were surveyed for Viola selkirkii, and plants were located at two of these sites. All reported sites on the Pike and San Isabel National Forests were visited as well as other sites with likely habitat where the species has never been reported. Site visits are summarized below. Newlin Creek Newlin Creek was visited on 15 June Four separate subpopulations (numbered NC1 4) were found. Plants were located near running water, and in some cases were in the area moistened by spray from the stream. Several other violets were seen in Newlin Creek, including Viola canadensis and Viola sororia. NC-1 Two vegetative plants growing within or immediately adjacent to the trail. Northing Easting Elevation 7,300 feet Habitat: Riparian area amongst mixed Douglas-fir/white fir. Other: Adjacent to Newlin Creek, east-facing gentle (<10 ) slope.

5 NC-2 One clump of plants growing in a fern grotto by a waterfall. Plants were in fruit. Northing Easting Elevation 7685 feet Associates: Dryopteris filix-mas, Aralia nudicaulis, Saxifraga odontoloma, Polypodium saximontana, Cystopteris reevesiana, Cystopteris fragilis, Mimulus sp. (plants were vegetative but most likely M. guttatus), thalloid liverworts, mosses. Habitat: Riparian area amongst mixed Douglas-fir/white fir. Shady north-facing gentle slope. Other: North-facing side stream of Newlin Creek with gentle (<10 ) slope. NC-3 Approximately 50 plants growing adjacent to the stream. Plants were in fruit. Northing Easting Elevation 7455 Associates: Dryopteris filix-mas, Aralia nudicaulis, Cystopteris reevesiana, Cystopteris fragilis, Rubus sp., Rudbeckia hirta, Galium sp., Arnica cordifolia, Actaea rubra. Habitat: Riparian area amongst mixed Douglas-fir/white fir. Shady north-facing gentle slope. Other: North-facing side stream of Newlin Creek with gentle (<10 ) slope. NC-4 Approximately 100 or more plants growing in a protected fern grotto. Plants were in fruit. Northing Easting Elevation 7450 Associates: Dryopteris filix-mas, Aralia nudicaulis, Cystopteris reevesiana, Cystopteris fragilis, Rubus sp., Rudbeckia hirta, Galium sp., Arnica cordifolia, Actaea rubra, Thalictrum sp., Cornus sericea. Habitat: Riparian area amongst mixed Douglas-fir/white fir. Shady north-facing gentle slope. Other: Adjacent to Newlin Creek with gentle (<10 ) east-facing slope.

6 Photo 1: Newlin Creek Habitat A fern grotto, the typical habitat for Viola selkirkii in Newlin Creek.

7 Photo 2: Viola selkirkii from Newlin Creek Map 1: Newlin Creek Survey Routes.

8 Map 2: Newlin Creek points. These points show the sites found in the course of surveys.

9 Hayden Creek Directed surveys were performed on the North, Middle, and South Prongs of Hayden Creek on 16 June The site was chosen due to its northern aspect and abundant water. No Viola selkirkii has been previously reported from the site and no plants were found during surveys, although apparently suitable habitat was seen. Several mossy, shady sites in the spray zone were located along with some of the associated plant species seen at the Newlin Creek sites. Several violets were located and identified during the survey, including Viola adunca, Viola canadensis, Viola renifolia, and Viola sororia. Map 3: Hayden Creek Survey Routes.

10 Montgomery Reservoir Lincoln Ice Falls above Montgomery Reservoir was visited on 17 June Viola selkirkii was discovered by Scott Smith at the base of cliffs adjacent to Lincoln Ice Falls. No plants were found at the base of the cliffs, but a new site was found below the cliffs. Viola labradorica was found growing immediately adjacent to Viola selkirkii. These are both small, blue-purple flowered violets, but the hairs on Viola selkirkii differentiate the two species. Approximately 20 plants. A few plants were in flower while the remainder were vegetative. Northing Easting Elevation 11,100 Associates: Salix brachycarpa, Aquilegia coerulea, Veratrum tenuipetalum, Pedicularis sp. (vegetative), Polygonum bistorta, Lonicera involucrata, Carex spp., Cirsium sp. (vegetative), Sibbaldia procumbens, Parnassia fimbriata, Viola labradorica, Noccaea montana, mosses. Habitat: Moist Engelmann spruce-alpine fir forest. Plants were located at the uppermost part of the forest amongst willows (shortfruit willow- Salix brachycarpa), just below alpine. Plants were feet from a rivulet in moist soil. Other: Northeast aspect with a steep (30 ) slope in partial shade. Photo 3: Habitat at Lincoln Ice Falls

11 Photo 4: Viola selkirkii near Lincoln Ice Falls Map 4: Survey Routes and Viola Site at Lincoln Ice Falls. The long red track to the right is a spurious track resulting from poor GPS satellite coverage.

12 Tappan Gulch near Platte Springs This site was visited on 17 June The site was reported by Sheila Lamb (botanist and range permit administrator on Pike National Forest), but no voucher specimens or photographs are available to verify identity of plants at the site. Several hours were spent on the hillside searching for Viola selkirkii. No plants were found and the habitat, a dry ponderosa pine-fescue grass forest with scattered aspen, seemed an unlikely site for Viola selkirkii. No other violets were seen at the site. The site was reported as N , E468192, at 8,430 feet. Photo 5: Habitat at Tappan Gulch

13 Map 5: Survey Routes Near Tappan Gulch

14 Platte Springs With the time remaining on 17-June-2010 after visiting Montgomery Reservoir and Tappan Gulch a brief directed survey was performed at Platte Springs near the Tappan Gulch site. No new locations of Viola selkirkii were found. Viola adunca and Viola sororia were seen during the survey. Map 6: Survey Route at Platte Springs The two red lines extending to the south are spurious tracks resulting from poor GPS coverage. Devils Head The Devil s Head site was visited on 18-June This is a known site and plants have been located there in 2008 by Scott Smith. This is a small site immediately adjacent to the Rampart Ridge Road with fewer than 30 plants known historically. Unfortunately no plants could be located despite an extensive search in the exact same area where they had been located in the past. Additional surveys were also performed in areas adjacent to the known site. Extensive erosion and downcutting have occurred at the site, and the moist mossy shelves above the stream appear to be drying and they have collapsed or are in the process of collapsing into a small streamlet. This erosion appears to be natural, and is likely due to the crumbly and erosive nature of the decomposing granitic soils found at the site. It seems likely that this site either has been or will be lost to natural processes.

15 No plants were located but approximately 30 plants have been reported in the past. Two other violets (Viola canadensis and Viola sororia) were seen at the site. Northing Easting Elevation 8,210 Associates: Salix spp., Arnica cordifolia, Viola rydbergii, Viola canadensis, Aralia nudicaulis, Fragaria virginiana, Valeriana capitata, Mertensia lanceolata, Epilobium angustifolium, Rosa sp., Arctostaphylos uva-ursi. Habitat: Moist Engelmann spruce-aspen forest. Plants were located on mossy shelves above a streamlet (now dry). Other: East aspect with a shallow (10 ) slope in partial to full shade. Photo 6: Habitat at Devil s Head site. Headcut is clearly visible.

16 Photo 7: Devil s Head habitat. Shelves of vegetation collapsing into eroding creek. Map 7: Devil s Head site

17 South Gerber Creek and Bear Creek The South Gerber and Bear Creek sites were visited on 18 June These sites were reported by contract botanists to Denny Bohon (fish biologist on the Pike National Forest), but no voucher specimens or photographs are available to verify identity of plants at the site. Several hours were spent at these two sites searching for Viola selkirkii. Several other violets were seen at the site, including Viola adunca, Viola canadensis, Viola renifolia, and Viola sororia. No plants were found at either site. The sites were reported as: South Gerber Creek: N , E494937, 7,500 feet. Bear Creek: N , E492361, 7,380 feet. Map 8: Gerber Creek

18 Map 9: Bear Creek

19 Pine Creek With the short time remaining on 18-June-2010 a small fern grotto on Pine Creek near Sprucewood was visited for a short survey. No Viola selkirkii has been reported from the site in the past. The site was chosen due to the presence of fern grottos similar to those found in Newlin Creek. Viola selkirkii was not located at the site. Viola canadensis was abundant at the site. Map 10: Pine Creek Summary Of the six reported Viola selkirkii sites on the Pike and San Isabel National Forests, only three have been verified through photographs or voucher specimens: Newlin Creek, Devil s Head, and Montgomery Reservoir. The three remaining sites have not been verified and Viola selkirkii could not be located at those sites during these surveys. These include the Bear Creek, Pine Creek, and Tappan Gulch sites. Unfortunately, the Devil s Head site has either been lost or will likely be lost in the future due to natural erosion. Thus, the Pike and San Isabel National Forests are home to only two known and verified Viola selkirkii sites. The three sites where Viola selkirkii is known on the Pike and San Isabel National Forests are quite different in habitat characteristics. The Newlin Creek sites are located in shaded sites near water, often in the spray of waterfalls, and grow alongside several uncommon species that are also disjunct in Colorado, including Aralia nudicaulis and Dryopteris filix-mas. The Montgomery Reservoir site is at the uppermost limit of subalpine forest amongst subalpine willows. The Devil s Head site is in a moist aspen-spruce forest. Given the broad variation in occupied habitat it is difficult to make generalizations

20 regarding where the species may be found on the Pike and San Isabel National Forests or elsewhere in the Rocky Mountains. The subalpine and aspen-spruce habitats are common on the Forest, while the Newlin Creek habitat type (protected fern grottos) are extremely rare on the Forest. However, given our current knowledge, it is clear that Viola selkirkii is quite rare throughout Colorado. Although it is clear that Viola selkirkii is quite rare in Colorado, it is also clear that the species has a greater ecological amplitude than previously believed. Previously believed to grow at elevations between approximately 6,000 9,000 feet, the new Montgomery Reservoir site is at 11,100 feet. It is also at the ecotone between subalpine spruce-fir forest and alpine, indicating that the species may be found in either habitat. The site is also further west than previously reported. It is adjacent to the continental divide, indicating that the plant may also inhabit the western slope of Colorado. Thus, abundant potential but previously unsurveyed habitat exists within the state. Based on our reference site visits and directed surveys we make the following recommendations to the Pike and San Isabel National Forests: 1. Due to the potential for mis-identification of Viola selkirkii, reports of the species should be verified through photographs or, preferably, voucher specimens in a public herbaria. 2. Due to the rarity of Viola selkirkii on the planning unit, in Colorado, and in region 2, known sites should be protected with vigor. 3. If possible, known sites should be periodically monitored to assess impacts (either natural or as a result of human activities) so that action may be taken to prevent loss of sites such as Devil s Head. 4. Perform additional directed surveys for the species, focusing on the following habitats: moist fern grottos, Newlin Creek, and subalpine sites similar to the Montgomery Reservoir site. Moist aspen-spruce sites in the Rampart Range should be spot checked, but success will likely be limited. Other Botanical Discoveries During the course of surveys diffuse knapweed (Centaurea diffusa) and Rocky Mountain blue columbine (Aquilegia saximontana). Diffuse knapweed Diffuse knapweed was found at two separate locations. One site with approximately 6 plants was located on the side of the Rampart Range Road near the reported Gerber Creek site. A second site with approximately plants was located west of Sprucewood above Pine Creek. GPS coordinates: Gerber Creek: N , E Elevation 7,800 feet. Pine Creek: N , E Elevation 6,780 feet.

21 Map 11: Diffuse knapweed at Gerber Creek

22 Map 12: Diffuse knapweed above Pine Creek

23 Rocky Mountain blue columbine Aquilegia saximontana was found at the Tappan Gulch site. Approximately 30 plants were found in shaded cracks of granite boulders on a west-facing 20 slope. Habitat at the site was ponderosa pine-douglas-fir forest with a common juniper-fescue grass understory. GPS coordinates: N , E Elevation 8760 feet. This is a surprising discovery at this site. The species is usually found at elevations between 10,000 and 13,000 feet in alpine sites, particularly amongst talus slopes. The University of Colorado and Rocky Mountain herbaria list 29 collections, three at about 9,000 feet and the rest between 10,000 and 13,000 feet. This site appears to be the lowest elevation site yet documented, and the first located amongst ponderosa pine and Douglasfir/fescue grass. Photo 8: Aquilegia saximontana at Tappan Gulch

24 Map 13: Aquilegia saximontana at Tappan Gulch

25 Literature Cited Martin, W. C., and C.E. Hutchins Flora of New Mexico. Bishen Singh Mahendra Pal Singh, India, and Koeltz Scientific Books, Germany. Harrington, H.D Manual of the plants of Colorado. Sage Books, Denver, CO. Hornbeck, H.J., C.H. Seig, and D.J. Reyher Conservation assessment for greatspurred violet in the Black Hills National Forest, South Dakota and Wyoming. U.S.D.A. Forest Service, Black Hills National Forest, Custer S.D.