Opuscula Philolichenum, 6: 1-XXXX
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Opuscula Philolichenum, 15: 56-81. 2016. *pdf effectively published online 25July2016 via (http://sweetgum.nybg.org/philolichenum/) Lichens, lichenicolous fungi, and allied fungi of Pipestone National Monument, Minnesota, U.S.A., revisited M.K. ADVAITA, CALEB A. MORSE1,2 AND DOUGLAS LADD3 ABSTRACT. – A total of 154 lichens, four lichenicolous fungi, and one allied fungus were collected by the authors from 2004 to 2015 from Pipestone National Monument (PNM), in Pipestone County, on the Prairie Coteau of southwestern Minnesota. Twelve additional species collected by previous researchers, but not found by the authors, bring the total number of taxa known for PNM to 171. This represents a substantial increase over previous reports for PNM, likely due to increased intensity of field work, and also to the marked expansion of corticolous and anthropogenic substrates since the site was first surveyed in 1899. Reexamination of 116 vouchers deposited in MIN and the PNM herbarium led to the exclusion of 48 species previously reported from the site. Crustose lichens are the most common growth form, comprising 65% of the lichen diversity. Sioux Quartzite provided substrate for 43% of the lichen taxa collected. Saxicolous lichen communities were characterized by sampling four transects on cliff faces and low outcrops. An annotated checklist of the lichens of the site is provided, as well as a list of excluded taxa. We report 24 species (including 22 lichens and two lichenicolous fungi) new for Minnesota: Acarospora boulderensis, A. contigua, A. erythrophora, A. strigata, Agonimia opuntiella, Arthonia clemens, A. muscigena, Aspicilia americana, Bacidina delicata, Buellia tyrolensis, Caloplaca flavocitrina, C. lobulata, C. soralifera, Candelariella antennaria, Dermatocarpon arenosaxi, Diplotomma subdispersa, Endocarpon pallidulum, Enterographa osagensis, Pseudosagedia chlorotica, Psoroglaena dictyospora, Punctelia missouriensis, Verrucaria calkinsiana, V. furfuracea, and V. sphaerospora. In addition, we report Acarospora erythrophora new for Kansas and Oklahoma, Enterographa osagensis new for Nebraska and South Dakota, and Pseudosagedia chlorotica new for Oklahoma. KEYWORDS. – Great Plains, floristic change, lichen community structure, Northern Glaciated Plains Ecoregion. INTRODUCTION Pipestone National Monument (PNM) encompasses 122 hectares (301 acres) in the Northern Glaciated Plains Ecoregion (Omernik & Griffith 2008), on the Prairie Coteau of southwestern Minnesota. Designated a national monument in 1937, PNM is located in Pipestone County, at the northwest edge of the town of Pipestone (44.041N, 96.325W; figure 1). Between 1975–2015, annual temperatures at PNM averaged 6.5C (43.7F), with mean monthly temperatures ranging from –11.1C (12.1F) in January to 21.8C (71.3F) in July. Average annual precipitation was 67.8 cm (26.7 inches), with most precipitation occurring between April and September (NOAA 2016). Between 1956–1970, average annual growing season open pan evaporation in the region was approximately 106.7 cm (42.0 inches) (Farnsworth et al. 1982), resulting in a negative net evaporation value (open pan evaporation minus annual precipitation) of approximately 38.9 cm (15.3 inches) and a precipitation to evaporation ratio of 0.63, within the 0.3–1.0 range typically attributed to temperate grasslands (Transeau 1905). 1CALEB A. MORSE – Biodiversity Institute, R.L. McGregor Herbarium, University of Kansas, 2045 Constant Ave., Lawrence, KS 66047, U.S.A – e-mail: [email protected] 2CORRESPONDING AUTHOR 3DOUGLAS LADD – The Nature Conservancy, 2800 S. Brentwood Blvd., St. Louis, MO 63144, U.S.A. – e- mail: [email protected] 56 Figure 1. Location of Pipestone National Monument, Pipestone Co., Minnesota (top right and left). Map of the the study area (bottom) with Sioux Quartzite outcrops indicated in orange, and sampling transects indicated in blue (1, Flats transect, 2, Upper Cliff, Mid-Cliff, and Lower Cliff transects; scale = 250 m). 57 The site is geologically and historically significant for its numerous high-quality pipestone (catlinite) quarries, which were developed and continuously worked by Native Americans from about 1200 CE (Corbett 1980) to the present day. Catlinite is a red metamorphic claystone that can be hand-carved into ceremonial pipes. This soft claystone is sandwiched between thicker layers of Precambrian Sioux Quartzite bedrock (Southwick et al. 1986). In addition to the subsurface quarries, three parallel north–south ridges of Sioux Quartzite form flat, low outcrops and a low line of cliffs at PNM (figure 2). The sheer red cliffs have a western exposure and rise up to five meters. A massive, abandoned sandstone railroad trestle stands over an ephemeral wetland toward the eastern boundary of the monument. Historically, the vegetation of PNM would have been dominated by tallgrass prairie, with rare woody vegetation restricted to sheltered sites and stream courses. During his 1835 expedition to the site, the painter George Catlin noted of the surrounding prairie that for “…a distance of forty or fifty miles, there was not a tree or a bush to be seen in any direction…” (Catlin 1839, p. 140), although his painting of the pipestone quarries shows a few shrubs or small trees (Catlin 1836–1837). When Bruce Fink visited the site in 1899, he observed that “…the few young trees found, though large enough to bear the foliaceous lichens which commonly migrate to rocks... scarcely bear a lichen of any kind…” (Fink 1902, p. 284). Over the past 115 years there has been a significant increase of trees and shrubs at PNM, probably due primarily to fire suppression and altered grazing and browsing regimes (Samson et al. 2004, Fuhlendorf et al. 2008, van Auken 2009). Deciduous trees and scattered shrub thickets have grown up along Pipestone Creek and the quartzite ridges. Today, vegetation at PNM includes remnant and replanted tallgrass prairie, bur oak (Quercus macrocarpa) woodland along the ridges, a narrow riparian woodland of boxelder (Acer negundo), common hackberry (Celtis occidentalis), green ash (Fraxinus pennsylvanica), and plains cottonwood (Populus deltoides subsp. monilifera) along the perennial Pipestone Creek, and Sioux Quartzite prairie— which develops over thin, seasonally saturated soils over quartzite bedrock (MDNR 2003). Scattered thickets of redosier dogwood (Cornus sericea subsp. sericea), Tatarian honeysuckle (Lonicera tatarica), and American plum (Prunus americana) are found in areas protected from fire. Tree ring analysis suggests that many of the bur oaks date to ca. 1880–1885 (Landers 1979) and as we document these trees now provide ample habitat for a rich corticolous lichen community. The land comprising PNM has a long history of lichenological study, beginning with the work of Bruce Fink, who gathered 5,500 specimens in Minnesota between 1896 and 1902 for his Ph.D. dissertation and as part of the Botanical Survey of Minnesota (Wetmore 1978). During the summer of 1899, he collected approximately 30 numbers at or near the site that is now PNM, and published the results in a preliminary report (Fink 1902). The site was resurveyed by Timothy Vinyard, who reportedly collected some 350 specimens during the field seasons of 1983–1984 in support of an update of the flora of PNM (Willson & Vinyard 1986). Finally, Gerald Wheeler collected 23 lichens from PNM on May 13, 1999. In light of the substantial floristic and management changes that PNM has undergone since Fink first visited the site, and as part of a larger effort to document the lichen flora of the Great Plains, we re-inventoried the lichens of PNM and report our results here. MATERIALS AND METHODS Field work for this project consisted of 28 field days between 2004 and 2015. Efforts were made to survey all habitats and substrates on the site. In all, 368 collections were obtained, principally by MKA; these have been deposited in the R.L. McGregor Herbarium at the University of Kansas (KANU). In addition, we reviewed 65 specimens deposited by Vinyard in the herbarium of PNM (hereafter, hb. PNM). We assume that the Vinyard specimens were deposited in hb. PNM as a synoptic collection representing the diversity of the 65 species reported in Willson and Vinyard (1986). The remaining 285 specimens collected by Vinyard in preparation for those authors’ report could not be located and are assumed to have been lost. Finally, we reviewed 51 specimens from MIN, representing the bulk of Fink’s collections from Pipestone, and a handful of specimens gathered by Wheeler and other collectors. Specimens were studied using dissecting and compound microscopes, and subjected to chemical analysis using standard spot tests (Brodo et al. 2001). Where it was required for positive identification, Thin Layer Chromatography (TLC) was conducted at KANU using solvent systems A and C following the methods of Orange et al. (2001). To assess patterns of saxicolous lichen inhabitancy at the site, and to develop a baseline for future monitoring and assessment, two transects were established on Sioux Quartzite exposures at PNM (figure 1): 58 Figure 2. Rock formations and bur oak woods of Pipestone National Monument. A, west-facing Sioux Quartzite cliffs, with bur oak woods in the foreground; B, wooded cliff and float rock below cliff; C, wooded cliff with abundant bur oak; D, boulders below cliffs; E, saxicolous lichen community including Acarospora contigua, Dimelaena oreina, and Physcia subtilis. (Photographs by Nickolee Larson.) 59 State/Province, Unit name Area Taxa included No. Reference