Microsoft word - libi final report.doc

A SURVEY OF THE VASCULAR PLANTS AND BIRDS OF LITTLE BIGHORN Department of Ecology and Evolutionary Biology The following report on vegetation and birds at the Little Bighorn National Battlefield includes three parts. The first is an annotated flora, based on a compilation of existing reports and on original field surveys. The second is an annotated checklist of birds seen at the Battlefield, based on original observations gathered in 1985-1986 and in 2002-2006. The third is a description of vegetative cover at the Battlefield, based on comparative analyses of data from 25 sampling plots, originally established and sampled in 1984-1986 and re-sampled in 2003. We also include in the final section an overall assessment of the condition of Battlefield vegetation and what we perceive to be issues of continuing and future management concern, including fire, invasive exotics, and the impacts of tourism and archaeological exploration. First, we thank Maureen O’Shea-Stone, who generously helped with field work and with assembly of the flora. Our special thanks go to those who facilitated our work at Little Bighorn National Battlefield. Thanks to Neil Mangum who suggested that we come back up for a second look at our work that he had facilitated in the 1980s. Michael Stops lent us red vests and let us wander to those special places where the plants and the birds took us. He supplied us with documents, his experiences, and his welcome in every visit to the Battlefield. We treasure his friendship, and admire his ability to carry out responsibilities far beyond any one person’s job description. Kitty Deernose let us work through photo archives again and again. John Doerner led us to literature that put everything else we did into the context of this unique place. Loreen Crooked Arm always greeted us with a smile at the front desk and knew where to find Michael and John. Mary Eggers of Little Big Horn College helped us put the Little Bighorn into a wider perspective. Finally, we are grateful that the National Park Service has added the University of Colorado to their program. This enabled us to do this study, and we are very grateful for their financial support and encouragement. Some individuals need special mention. Tara Carolin and Lisa Gerloff kept us informed. Michael Britton, Brent Frakes, and Billy Schweiger made our data seem significant and helped us put this project into proper perspective. Flora of the Little Bighorn National Battlefield………………. 3-12 Birds of the Little Bighorn National Battlefield………………. 13-22 Vegetation of the Little Bighorn National Battlefield………… 23-44 FLORA OF THE LITTLE BIGHORN NATIONAL BATTLEFIELD The following flora of the Little Bighorn Battlefield is based on personal observations at the site in 1984-1986 and 2002-2006. We also consulted our final report to the National Park Service in 1987 (Bock et al. 1987), and the unpublished list of plants of the Battlefield compiled by Sara Simonson and others in 2000. Plant systematics at the present time is undergoing major reorganizations based on modern developments in the fields of plant genetics and evolution. Therefore, the nomenclature we have used in this flora must be considered a work in progress. Our primary source for nomenclature was McGregor et al. (1986), supplemented by information in Dorn (1984, 1992) and Weber (1990). Throughout the study we consulted with and received help from the Herbarium staff of the University of Colorado’s Museum. Bock, J. H., C. E. Bock, and M. O’Shea Stone. 1987. The effects of fire on virgin northern mixed grassland at Custer Battlefield National Monument. Final Report to the National Park Service, U. S. Department of the Interior, Washington, D. C. Dorn, R. D. 1984. Vascular plants of Montana. Mountain West Publishing, Cheyenne, Dorn, R. D. 1992. Vascular plants of Wyoming. 2nd ed. Mountain West Publishing, McGregor R. L., T. M. Barkley, R. E. Brooks, and E. K. Schofield. 1986. Flora of the Great Plains. University of Kansas Press, Manhattan, Kansas. Weber, W. A. 1990. Colorado Flora: Eastern Slope. University Press of Colorado, Flora of the Little Bighorn National Battlefield
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BIRDS OF THE LITTLE BIGHORN NATIONAL BATTLEFIELD The attached annotated checklist is based on observations at both the main part of the battlefield and at the Reno-Benteen site. Fieldwork was conducted in June of 1985 and 1986, and on fourteen days between July 2002 and May 2006. The earliest date was May 11 and the latest date was October 21, so we have no data for the winter season. We recorded the presence of 60 species in five different habitat types: open grassland, sage-grassland, shrubby swales and ravines, river bottomland, and landscaped areas around the Battlefield headquarters and cemetery. The 1985 and 1986 observations were part of a study examining habitat selection by songbirds in burned versus unburned sage-grasslands (Bock and Bock 1987), which demonstrated the importance of big sagebrush to birds such as grasshopper sparrow, Brewer’s sparrow, lark bunting, and lark sparrow. In those years, these species were common only at the Reno-Benteen site, which had not burned and which supported good stands of big sage. The only common grassland birds on burned sage-free grasslands at LIBI proper were the vesper sparrow and western meadowlark. By 2006, grasshopper sparrows, Brewer’s sparrows, and lark sparrows had become relatively common at the main LIBI site, associated with increasing cover of shrubs such as Prunus virginianus and Rhus trilobata in swales and ravines. By contrast, fires at the Reno-Benteen site had killed big sage, and the shrub-dependent bird species were no longer common there. These results are generally consistent with avian responses to fire in sage-grasslands elsewhere in North America (Knick et al. 2005), and they illustrate the importance of at least some scattered emergent shrub cover to a variety of grassland birds. From an avian perspective, loss of big sage from fires at LIBI has had a negative impact on its biological diversity. By far the richest avian habitat at LIBI is the river bottomland, with its open water, riparian trees, and rich shrubby understory. Riparian habitats have similar value for birds throughout arid parts of western North America, as has long been recognized and studied (e.g., Johnson and Jones 1977, Skagen et al. 1998, Saab 1999). Protection of the LIBI river bottomlands from livestock grazing doubtless is responsible for their well-developed understory, which can benefit a variety of birds dependent on heavy ground cover (e.g., Saab et al. 1995, Stanley and Knopf 2002). Riparian birds likely dependent on understory vegetation at the Battlefield include veery, gray catbird, brown thrasher, spotted towhee, and song sparrow. By contrast, birds such as the ring-neck pheasant, mourning dove, black-billed magpie, American crow, and perhaps some of the flycatchers, are likely to be more abundant in riparian areas outside the Battlefield that are dedicated to agriculture and housing, and that support relatively low and sparse understory vegetation. Future ornithological inventory and research work at LIBI could profitably be focused on three aspects. The first would be to monitor responses of birds to increases in upland shrubby vegetation that are continuing following the 1983 fire, since understanding of long-term fire-effects on birds in sage-grasslands remains limited (Knick et al. 2005). The second would be more work in the LIBI river bottomlands, both to search for uncommon species that may have been missed in earlier surveys and to confirm nesting status for as many species as possible. A third possibility would be to expand the scale of riparian bird surveys (Knopf and Samson 1994), to include nearby agricultural areas along the river, in order to place the distinctive undisturbed bottomlands on the battlefield in a wider landscape context. Literature Cited Bock, C. E., and J. H. Bock. 1987. Avian habitat occupancy following fire in a Montana shrubsteppe. Prairie Naturalist 19: 153-158. Johnson, R. R., and D. E. Jones (technical coordinators). 1977. Importance, preservation, and management of riparian habitat: a symposium. USDA Forest Service General Technical Report RM-43. Rocky Mountain Station, Fort Collins, Colorado. Knick, S. T., A. L. Holmes, and R. F. Miller. 2005. The role of fire in structuring sagebrush habitats and bird communities. Studies in Avian Biology No. 30: 63-75. Knopf, F. L., and F. B. Samson. 1994. Perspectives on avian diversity in western riparian ecosystems. Conservation Biology 8:669-676. Saab, V. A. 1999. Importance of spatial scale to habitat use by breeding birds in riparian forests: a hierarchical analysis. Ecological Applications 9: 135-151. Saab, V. A., C. E. Bock, T. D. Rich, and D. S. Dobkin. 1995. Livestock grazing effects in western North America. Pp. 311-353 in (T. E. Martin and D. M. Finch, editors) Ecology and management of neotropical migratory birds. Oxford University Press, New York. Skagen, S. K., C. P. Melcher, W. H. Howe, and F. L. Knopf. 1998. Comparative use of riparian corridors and oases by migrating birds in southeast Arizona. Conservation Biology 12: 896-909. Stanley, T. R., and F. L. Knopf. 2002. Avian responses to late-season grazing in a shrub-willow floodplain. Conservation Biology 16:225-231. Bird species recorded at the Little Bighorn Battlefield National Monument, during summer, spring, and fall of 1985-1986 and 2002-2006, by Carl Bock and Jane Bock. Status Grassland Grassland Headquarters Bottomland Ravines (Anas platyrhynchos) Common Merganser (Mergus merganser) Ring-necked Pheasant (Phasianus colchicus) Sharp-tailed Grouse (Tympanuchus phasianellus) Great Blue Heron Status Grassland Grassland Headquarters Bottomland Ravines (Circus cyaneus) Swainson’s Hawk (Buteo swainsoni) Red-tailed Hawk (Buteo jamaicensus) Ferruginous Hawk (Buteo regalis) American Kestrel (Charadrius vociferus) Spotted Sandpiper (Actitis macularia) Upland Sandpiper (Bartramia longicauda) Mourning Dove Status Grassland Grassland Headquarters Bottomland Ravines (Streptopelia decaocto) Belted Kingfisher (Picoides pubscens) Hairy Woodpecker (Picoides villosus) Northern Flicker (Contopus sordidulus) Eastern Kingbird (Tyrannus tyrannus) Western Kingbird Status Grassland Grassland Headquarters Bottomland Ravines (Lanius ludovicianus) Black-billed Magpie (Corvus brachyrhynchos) Horned Lark (Eremophila alpestris) Northern Rough-winged Swallow (Stelgidopteryx serripennis) Cliff Swallow (Petrochelidon pyrrhonota) Barn Swallow (Hirundo rustica) Black-capped Chickadee (Parus atricapillus) White-breasted Nuthatch Status Grassland Grassland Headquarters Bottomland Ravines (Catharus fuscescens) American Robin (Turdus migratorius) Gray Catbird (Dumetella carolinensis) Brown Thrasher (Toxostoma rufum) European Starling (Bombycilla cedrorum) Yellow Warbler (Dendroica petechia) Wilson’s Warbler Status Grassland Grassland Headquarters Bottomland Ravines (Pipilo maculatus) Brewer’s Sparrow (Spizella breweri) Chipping Sparrow (Spizella passerina) Vesper Sparrow (Pooecetes gramineus) Lark Bunting (Calamospiza melanocorys) Lark Sparrow (Chondestes grammacus) Grasshopper Sparrow (Ammodramus savannarum) Song Sparrow (Melospiza melodia) White-crowned Sparrow Status Grassland Grassland Headquarters Bottomland Ravines (Pheucticus melanocephalus) Western Meadowlark (Sturnella neglecta) Brewer’s Blackbird (Euphagus cyanocephalus) Common Grackle (Quiscalus quiscula) Brown-headed Cowbird (Molothrus ater) Bullock’s Oriole (Carpodacus mexicanus) American Goldfinch (Carduelis tristis) 1R = likely year-round resident; S = likely summer resident, probably nesting; M = likely migrant only. These designations are not based on year-round surveys of the Battlefield, but on published information about species distributions in the region. 2Open grasslands are those without sagebrush - principally areas with a history of fire 3Sage grasslands were sampled primarily on the Reno-Benteen site in 1985 and 1986, prior to fire, but also on the few remaining sage-dominated parts of the Battlefield in 2002-2006. 4Includes the woodlands along the Little Bighorn River, cliffs adjacent to the river, and the water and shorelines themselves. 5Includes especially Deep Ravine and similar areas on the Battlefield, dominated by shrubs such as chokecherry and snowberry. 6Status uncertain; first seen at Battlefield headquarters area in May, 2006.
VEGETATION OF THE LITTLE BIGHORN NATIONAL BATTLEFIED A 1983 wildfire burned about 90% of upland mixed grass prairie at the Little Bighorn National Battlefield (LIBI) in south-central Montana. In May 2003 we sampled vegetation on 20 plots that had burned 20 years earlier and on 5 plots spared by the fire. Our goals were to evaluate any residual impacts of that fire, and to assess overall condition of Battlefield vegetation. The 1983 fire killed 100% of the dominant upland shrub, big sagebrush (Artemisia tridentata), and there was no evidence of big sage recovery after 20 years. Other shrubs (especially Symphoricarpos occidentalis, Rosa arkansana, Prunus virginiana, and Artemisia cana) survived or recovered from the fire, and these were particularly abundant in 2003 in swales and small ravines on the Battlefield. Although the small number of unburned plots limited the power of our statistical comparisons, the data suggest that even after twenty years certain native grasses and forbs continued to benefit from effects of the 1983 fire, whereas exotic grasses (especially Bromus japonicus) remained more common on unburned sites. Given 1) the vulnerability of big sagebrush to burning, 2) the lack of recruitment even after 20 years, and 3) the value of big sage cover to birds and likely to other animals, we recommend suppression rather than prescribed use of fire for LIBI at the present time. Future prescribed burning might be indicated if there is some recovery of big sagebrush in areas that could be exempted from fire, and/or if there is a trend toward decreasing relative abundance of native vs. exotic grasses and forbs. Continuing threats to native Battlefield vegetation include the spread of introduced exotic plant species, especially Poa bulbosa, Russian olive (Eleagnus angustifolia), and honeysuckle (Lonicera tatarica). At the same time, native willows (Salix spp.) appear to have declined since the time of the Battle, and these are candidates for judicious re-introductions into riparian bottomlands. Other potential threats to native vegetation include the impacts of tourists walking the Battlefield, and of future archaeological excavations. The Little Bighorn National Battlefield (LIBI) lies in and adjacent to the valley of the Little Bighorn River, in Bighorn County, Montana. Upland portions of the Battlefield consist largely of northern mixed grass prairie, dominated by perennial grasses in the genera Agropyron, Poa, Stipa, and Bouteloua (Risser et al. 1981). The Battlefield has been ungrazed since it was fenced in 1891, whereas the majority of regional grasslands have long been dedicated to livestock grazing. Numerous bison (Bison bison) grazed the prairies of eastern Montana prior to the introduction of livestock (Lyman and Wolverton 2002). However, their migratory and nomadic behavior would have resulted in relatively episodic grazing compared to that of fenced domestic livestock (Berger 2004). Our general impression of the Battlefield’s grasslands is that they are in good condition overall, and that certain areas represent outstanding examples of regional grassland communities. However, LIBI grasslands have in the distant and recent past experienced degradation from a variety of sources. Perhaps the earliest exogenous threat came from horses. Based on the earliest historic records, the region of the Big Horn, Little Big Horn, Rosebud, and Tongue Rivers was noted for its large herds of bison during late spring and summer, and for concentrations of Indians whose horses doubtless had a major impact on regional grasslands beyond that of the native bison (Marquis 1987, Robinson 1995). Subsequent threats have included livestock grazing, alteration of natural fire regimes, and the introduction and spread of non-native plants. We cannot know the exact appearance of the Battlefield on 25 June 1876, but we have significant clues about its general appearance, both from the early photographic record (see Battlefield archives) and from descriptions of the site provided by participants in the Battle. The Indian interviews are especially valuable because of their apparent knowledge of the natural surroundings. Of particular significance in light of current Battlefield condition, there are many references to big sagebrush (Artemisia tridentata) at the scene on the day of the battle. For example, the Cheyenne Two Moons mentions the sage-covered hills on the day of the battle, while the Cheyenne Big Beaver and others recalled Captain Keogh’s scalp hanging from a sage bush (Hardorff 1995). Most of the soldiers were from elsewhere and their knowledge of plant life in the western Great Plains was lacking. Interestingly, the individuals who might have been able to give the most detailed descriptions were Custer himself, who was an amateur botanist, along with another Battle casualty, reporter Mark Kellogg (Progulske 1974). A wildfire on 10 August 1983 burned approximately 90% of the upland areas on the main Battlefield site. Because of the long history of protection from livestock grazing, the 1983 LIBI burn provided an unusual opportunity to study fire effects in a mixed grass prairie that carried fuel loads perhaps comparable to those of some but not all pre-historic times and places (Brockway et al. 2002). Evidence from pre-burn photographs and from the small areas spared by the 1983 fire suggest that the majority of LIBI uplands supported stands of big sagebrush (Artemisia tridentata) mixed into the prairie, probably since the time of the battle and likely before (Bock et al. 1987). In the summers of 1984-1986 we sampled vegetation on upland portions of the Battlefield, on 25 permanent 20 x 20-m plots, five of which had not burned and 20 of which had burned in the 1983 fire. Results (Bock et al. 1987) indicated that the fire killed virtually 100% of the big sagebrush, and that no sage recruitment occurred over the first three post-fire years. Other fire effects were relatively minor. Most other shrubs and succulents appeared to survive or to recover quickly from the fire. The data suggested that native grasses and certain native forbs may have benefited from the fire, while exotic grasses (especially Bromus japonicus) may have declined. However, the data supporting these conclusions were limited by the lack of pre-burn information, by the relatively small unburned area and resulting small number of unburned plots (five) that we sampled, and by the short (three-year) duration of the study. In May 2003 we re-sampled vegetation on the 25 permanent plots that were used in the earlier study. Our study had two objectives. The first was to gain a longer-term perspective on effects of the 1983 fire, and specifically to determine 1) whether any recruitment of big sagebrush had occurred after 20 years, 2) whether other shrubs and succulents had increased in abundance or distribution, and 3) whether native grasses and forbs had continued to hold their apparent edge over exotic species in the burned sites. Our second objective was to assess the overall condition of Battlefield vegetation, in terms of native versus exotic species, and to make recommendations about ways to manage the site for conservation of native biological diversity. In May, 1984, we established twenty-five 20x20-m vegetation sampling plots at the Little Bighorn National Battlefield, twenty of which had burned in the 11 August 1983 wildfire that covered most of the main battlefield, and five of which were located on those small portions of the site spared by the fire (Bock et al. 1987). Prior to the start of vegetation data collection in 1984, an archaeological team had mapped the Battlefield on a 100-m grid, using short pieces of rebar that stood about 15 cm above the ground. Each rebar stake was covered with a yellow plastic cap marked with a north (N) by east (E) coordinate; the grid ran parallel to the northwestern and northeastern monument boundaries, rather than following true N-S, E-W compass directions. We used these rebar stakes to mark the southeastern corner of 24 of the 25 plots. Our first task in 2003 was to relocate the 25 plots, by which time most of the plastic rebar caps had deteriorated to the point where the grid marks were no longer legible. However, we were able to relocate all but one of the plot markers, and we then gave each a GPS notation from its southeastern corner (Table 1). The plot we could not relocate was adjacent to and partly beneath the new Indian Memorial that was not present at the time of our earlier study. We located another plot near this area for our sampling in 2003 (Table 1; the former plot B20). For analysis and comparison of 2003 vegetation data, we designated 16 of the 20 plots burned in 1983, and all five of the unburned plots, as “unburned uplands” (Tables 2-5), based on their similar topographic positions and vegetative condition. The remaining four burned plots were located in swales and small ravines that by 2003 had begun to support distinctive assemblages of shrubs; there were no topographically-comparable sites on the battlefield that had been spared by the 1983 fire. We collected three sorts of vegetation data on the plots in May 2003, modeled after our earlier study. First, we set out three 20-m transects, one on the east boundary, one on the west boundary, and one crossing the middle of each plot. We then determined plant canopy cover at 120 points spaced at 0.5-m intervals along the three transects. Plants were identified to species, and unoccupied points were categorized as either bare ground or litter. We pooled data from each of the 120 points on each plot to generate a single percent canopy cover estimate for each plant species on each of the 25 plots. Second, we measured percent frequency of occurrence for each plant species on each plot, by recording its presence versus absence inside fifteen 250 cm quadrats, spaced at 5-m intervals along two sides and one interior transect on each plot. Finally, we counted the total numbers of each shrub and succulent inside the entirety of each plot, as a measure of its density. We also measured the maximum height and maximum width (cm) of up to 30 individuals of each shrub and succulent species on each plot, for future comparison with similar data collected in 1984-1986. We computed the mean and standard error of percent cover, percent frequency, and (for shrubs and succulents only) density of each plant species, for plots in each of the three habitat categories (Tables 2-4). We also pooled cover and species occurrence (richness) data into various plant categories (Table 5). Because data for most plant species violated assumptions for analyses of variance (Zar 1999), we computed the Kruskal-Wallis H-statistic as a nonparametric alternative for testing for significant differences among habitats. All statistical tests were performed in Statview 5.0.1 (SAS Publishing, 1999), with P < 0.05 considered significant, and 0.05 < P < 0.10 as marginally significant. Given the large number of comparisons involved, P-values > 0.01 should be interpreted with caution. Shrubs and succulents - Big sagebrush (Artemisia tridentata) was completely missing from all the plots that had burned in 1983, despite 20 years of post-fire vegetative growth (Table 2). By contrast, the shrub Artemisia cana was abundant in all three habitats. Various other shrubs (especially Prunus virginianus, Rosa arkansana, and Symphoricarpos occidentalis) were confined largely to the four plots located in swales and small ravines. Our data suggest that the cactus Opuntia fragilis may have been more abundant in level to rolling uplands than it was in swales (Table 2). Overall shrub canopy and combined shrub/succulent species richness were higher on unburned plots and in swales than on burned uplands (Table 5). Graminoids - We recorded 13 grass and one sedge species on the 25 plots in 2003. There were few significant differences in either canopy or frequency among habitats (Table 3). However, the data suggest that canopy of native species may have been higher in areas burned in 1983, while an opposite (but non-significant) trend was apparent for exotic grasses, the most abundant of which was Bromus japonicus (Tables 3 and 5). Forbs – We recorded 46 forb species on the 25 plots in 2003. Most were uncommon and did not differ in canopy or frequency among habitats (Table 4). Species richness of native forbs was marginally higher on burned than on unburned plots (Table 5), while combined canopy cover of native forbs showed a similar but nonsignificant trend. Residual Effects of the 1983 Fire. As in our earlier study (Bock et al. 1987), the small number of plots at the Little Bighorn National Battlefield (LIBI) spared by the 1983 fire (n = 5) reduced the power of statistical comparisons of data from burned vs. unburned areas (Tables 2-5). The power of these tests was further reduced by our realization that four of the 20 burned plots were located in shrubby swales and small ravines not represented in unburned landscapes, so that it was necessary to treat these as a distinct habitat type. Despite these limitations, vegetation data gathered in 2003, twenty years after the 1983 fire, added a longer-term perspective to our earlier work, and confirmed some of our earlier conclusions. Uplands at the Little Bighorn National Battlefield (LIBI) are part of the North American mixed grass prairie, an ecosystem in which fire has long been a regular and natural event (Risser et al. 1981, Pylypec and Romo 2003). However, fire frequency has been episodic in this region historically and pre-historically, related to climatic cycles (Umbanhowar 1996, Brown et al. 2005) and probably to fuel reductions caused by ungulate grazing (Briggs et al. 2002). Therefore, ecological opportunities have long existed across the northern Great Plains for plants that are intolerant of fire, as well as for those dependent upon or unaffected by it. Photographic and other historic evidence suggests that big sagebrush (Artemisia tridentata) was a dominant upland shrub along the Little Bighorn since the time of the battle and likely before (Bock et al. 1987). Big sagebrush is well-known to be killed by fire, with post-burn recovery taking 35 to more than 200 years (Baker 2006). Our results at LIBI are entirely consistent with these other studies, since we did not record a single big sagebrush plant on any of our burned plots in 2003, 20 years after the 1983 fire killed all sagebrush. At the same time, the small unburned portions of the Battlefield have continued to support good stands of big sagebrush. Ground cover at LIBI is relatively lush due to long-term absence of ungulate grazing, and this may have reduced opportunities for recruitment of big sagebrush seedlings after the fire (Austin and Urness 1998). However, the congeneric silver sage (Artemisia cana) has recovered and recruited well since the fire, both in uplands and in swales (Table 2). Shrubs largely restricted to swales and ravines at LIBI, such as chokecherry (Prunus virginiana), snowberry (Symphoricarpos occidentalis) and rose (Rosa arkansana), also apparently suffered little or no long-term negative effects of the 1983 fire (Table 2). Other studies confirm that these or closely related shrubby species either survive fire or recruit well post-fire (e.g., Bock and Bock 1984, Romo et al. 1993, Nadeau and Corns 2002). Because of lack of unburned (control) habitats on the Battlefield, we were unable to determine whether 2003 densities of shrubs in swales and small ravines were higher or lower or no different than they were prior to the 1983 fire. However, the 2003 abundances and distributions of these shrubs were comparable to those in 1985 and 1986 (Bock et al. 1987). Invasions of the exotic annual cheatgrass (Bromus tectorum) throughout much of the Great Basin have increased fire frequency and caused widespread loss of big sagebrush (Knick and Rotenberry 1997, Baker 2006). Because Bromus tectorum thrives in the presence of fire, many former sage-dominated shrubsteppe ecosystems now exist as near monocultures of this self-perpetuating annual grass. A related species, Bromus japonicus, is common at LIBI. However, in contrast to its effects on cheatgrass, fire can negatively impact Bromus japonicus populations, by reducing litter accumulations that favor seed production, seedling survival, and growth (Whisenant 1990). Our data from LIBI are consistent with these findings, since Bromus japonicus was more common in 2003 in areas spared by the 1983 fire, although the small sample size and high variance among our unburned plots precluded statistical support for this conclusion (Table 3). Certainly there is no evidence from our work to suggest that future fire at LIBI would drive its uplands toward an alien-dominated grassland, since the trend was toward higher cover of native vs. exotic grasses in areas burned in 1983 compared to those that did not (Table 5). Canopy cover and frequency of native vs. exotic forbs showed the same trend (Table 5). Species richness of succulents and shrubs was higher in burned swales and small ravines than in either burned or unburned uplands (Table 5), confirming the overall importance of this sort of topographic heterogeneity to plant species richness in the northern mixed grass prairie (Umbanhowar 1992). Species richness of native forbs was marginally higher on burned than on unburned plots, while species richness of native grasses showed the same trend (Table 5). These results suggest that most of the native flora of LIBI uplands is at least fire tolerant if not fire-dependent, which confirms the historic and continuing importance of fire in the region (Brown et al. 2005). However, big sagebrush is very important to the upland avifauna along the Little Bighorn (Bock and Bock 1987), and likely to other components of animal biodiversity as well, and our data show that fire will exclude big sagebrush for long periods. Threats to the Battlefield Vegetation, and Management Recommendations. Based upon our experiences at LIBI since 1983, the most obvious ongoing and increasing threat to Battlefield biodiversity comes from the enormous visitor pressure on this famous spot in American history. The potential visitor impacts on LIBI grasslands are similar to those that threaten ecotourism sites everywhere (Penksza et al. 2003, Kruger 2005), and include the destruction of native vegetation through trampling, and increased abundance and distribution of exotic species through propagule dispersal and creation of bare ground for colonization. The management decisions for LIBI that we have observed over these two decades earn our admiration. The re-working of visitor movement patterns and the excellent trail relocations, along with appropriate enforcement to keep visitors on the trails, have conserved and restored portions of the grassland. Exotic vegetation is often a companion of tourists. The exotic bromes (Bromus japonicus and B. tectorum) are of relatively minor concern because of their inability to spread into the grassland at the expense of native grass species. Rather, they seem to fill in gaps where the native floral cover has been interrupted. But another exotic grass, Poa bulbosa, deserves special attention. It was not observed on the Battlefield or in the vicinity of Hardin, Montana, in the 1980s. We first observed it along some town streets in Hardin in 2003, and noted it then on one isolated field plot (B6) and in several areas along the road near Last Stand Hill. By May 2006, it lined the entrance road to the Battlefield and was conspicuous along the Battlefield roads themselves. It also had moved out from the roadsides into the grassland itself, although it has not yet established at the Reno-Benteen site in any major way. Judging by its behavior both in Hardin and at the Battlefield, disturbed roadsides are highly receptive to Poa bulbosa. It also is invading established grasslands away from roadsides and trails in places where vegetation cover is not dense. If control for this species is considered, we recommend pulling it by hand at the outer edges of its distribution in order to keep its spread under control. Pesticide use is not recommended because of the impact the pesticide would have on the less robust native species within the grassland. Directional natural selection has led many exotic invasives to resist pesticide dosages that are damaging or lethal to native plants, especially native dicotyledons and other broad-leaved species. In the 1980s we observed some disturbance to LIBI grasslands related to archaeological excavations that followed the 1983 fire, which we discussed with Dr. Douglas Scott, head of the excavation team. Dr. Scott was aware of the potential destruction of vegetation on the site. He assured us that re-soding would take place following completion of the excavations, and it did. However, in 2003 we found a correlation between former excavation sites and the presence of exotics, especially Poa bulbosa, suggesting a residual disturbance effect. We hope and expect that any future explorations will involve less invasive methods now available in archaeological research, including ground penetrating radar, FLIR, SWIR, GPS, and aerial and ground-level LIDAR mapping. It might be appropriate for the management of LIBI to call attention, through signage and interpretive events, to the inherent natural value and biodiversity of the healthy grass and shrub habitat. This should be of interest not only to those visitors oriented toward natural history, but also to those interested in the human history of the site in terms of the appearance of the Battlefield. Thanks to the regrowth and spread of Artemisia cana, the Battlefield must now rather closely resemble how it looked on the 25th of June, 1876, even though A. tridentata does not dominate the site as it did then. The physiognomy of A. cana is considerably less robust than A. tridentata, but it provides the same general aspect. Given the vulnerability of Artemisia tridentata to burning, and its recent losses at both the Reno-Benteen and main parts of LIBI, we recommend suppression rather than prescribed use of fire for the Battlefield at the present time. Future use of prescribed fire might be indicated if there is some recovery if big sagebrush in areas that could be exempted from burning, and/or if there is a trend toward decreasing relative abundance of native vs. exotic grasses and forbs. Riparian habitats are uncommon in southeastern Montana as they are throughout much of the West, and remnants stands often are in severely degraded condition (e.g., Johnson and Jones 1977). Riparian areas of LIBI along the Little Bighorn River are particularly diverse because of their long history of protection from grazing, but they could benefit greatly from some active management. First, there are at least two non-native woody species that need to be removed or at least discouraged: honeysuckle (Lonicera tatarica) bushes and Russian olive (Eleagnus angustifolia). Both hold the potential for crowding out native riparian species. On the other hand, there are two woody species that need special nurturing and perhaps even some judicious plantings. These are the willows Salix amygdaloides (peachleaf willow) and S. exigua (sandbar willow). Willows are deserving of special attention at LIBI not only for their intrinsic value as part of the native flora, but also because of their particular significance to native peoples. Willows have been documented in numerous archeological and ethno-botanical studies as being of great significance to Indians throughout the Americas. Uses ranged from medicinal (active ingredients from aspirin are in willow) to basket making and shelters (Duke 1997). Both willows at LIBI likely were present and used by the tribes involved in the gathering along the river at the time of the Battle. Noisy Walking was sheltered “under a willow dome” that was erected at the end of the Battle and that was visited by Wooden Leg and others (Michno 1997). Perhaps the most interesting detail concerning willow comes from an interview with Young Two Moons who said (Hardorff 1995: 133) “After the fight was over, we gathered in the river bottom and cut willow sticks, then some Indians were delegated to go and throw down a stick wherever they found a dead soldier, and then they were ordered to pick up the sticks again, and in this way we counted the number of dead. It was about six times we had to cut willow sticks, because we kept finding men all along the ridge. We counted four hundred eighty-eight with our sticks along the ridge.” (Hardorff has a footnote about this number being in error.) We found willows to be very scarce in the riparian bottomlands at LIBI, which suggests that they may have declined significantly since the time of the battle. However, we found numerous willows along the Little Bighorn at Garryowen, and also near the site of the Battle of the Rosebud. Cuttings from these trees could be used to revegetate riparian woodlands at LIBI. Austin, D. D., and P. J. Urness. 1998. Vegetal change on a northern Utah foothill range in the absence of livestock grazing between 1948 and 1982. Great Basin Naturalist 58: 188-191. Baker, W. L. Fire and restoration of sagebrush ecosystems. Wildlife Society Bulletin 34: Berger, J. 2004. The last mile: how to sustain long-distance migration in mammals. Bock, C. E., and J. H. Bock. 1987. Avian habitat occupancy following fire in a Montana shrubsteppe. Prairie Naturalist 19: 153-158. Bock, J. H., and C. E. Bock. 1984. Effect of fires on woody vegetation in the pine- grassland ecotone of the southern Black Hills. American Midland Naturalist 112: 35-42. Bock, J. H., C. E. Bock, and M. O’Shea Stone. 1987. The effects of fire on virgin northern mixed grassland at Custer Battlefield National Monument. Final Report to the National Park Service, U. S. Department of the Interior, Washington, D. C. Briggs, J. M., A. K. Knapp, and B. L. Brock. 2002. Expansion of woody plants in tallgrass prairie: a fifteen-year study of fire and fire-grazing interactions. American Midland Naturalist 147: 287-294. Brockway, D. G., R. G. Gatewood, and R. B. Paris. 2002. Restoring fire as an ecological process in shortgrass prairie ecosystems: initial effects of prescribed burning during the dormant and growing seasons. Journal of Environmental Management 65: 135-152. Brown, K. J., J. S. Clark, E. C. Grimm, J. J. Donovan, P. G. Mueller, B. C. S. Hansen, and I. Stefanova. 2005. Fire cycles in North American interior grasslands and their relation to prairie drought. Proceedings of the National Academy of Sciences 102: 8865-8870. Duke, J. A. 1997. The green pharmacy. Rodale Press, Emmaus, Pennsylvania. Hardorff, R. G. (editor). 1995. Cheyenne memories of the Custer fight. University of Johnson, R. R., and D. E. Jones (technical coordinators). 1977. Importance, preservation, and management of riparian habitat: a symposium. USDA Forest Service General Technical Report RM-43. Rocky Mountain Station, Fort Collins, Colorado. Knick, S. T., and J. T. Rotenberry. 1997. Landscape characteristics of disturbed shrubsteppe habitats in southwestern Idaho (USA). Landscape Ecology 12: 287-297. Kruger, O. 2005. The role of ecotourism in conservation: panacea or Pandora’s box? Biodiversity and Conservation 14: 579-600. Lyman, R. L., and S. Wolverton. 2002. The late prehistoric-early historic game sink in the northwestern United States. Conservation Biology 16: 73-85. Marquis, T. B. 1987. Custer on the Little Big Horn (2nd edition). Reference Michno, Gregory F. 1997. Lakota moon: The Indian narrative of Custer’s defeat. Mountain Press Publishing Company, Missoula, Montana. Nadeau, L. B., and I. G. W. Corns. 2002. Post-fire vegetation of the montane natural subregion of Jasper National Park. Forest Ecology and Management 163: 165-183. Penksza, K, A. Barczi, M. Nerath, and B Pinter. 2003. Chances of regeneration after changes in utilization in grasslands on the Tihany Peninsula. Novenytermeles 52:167-18. Progulske, D. R. 1974. Yellow ore, yellow hair, yellow pine. Bulletin 616, Agricultural Experiment Station, South Dakota State University, Brookings, South Dakota. Pylypec, B., and J. T. Romo. 2003. Long-term effects of burning Festuca and Stipa- Agropyron grasslands. Journal of Range Management 56: 640-645. Risser, P. G., E. C. Birney, H. D. Blocker, S. W. May, W. J. Parton, and J. A. Wiens. 1981. The true prairie ecosystem. Hutchinson-Ross Publishing Company, Stroudsburg, Pennsylvania. Robinson, C. M. III. 1995. A good year to die. The story of the great Sioux war. Romo, J. T., P. L. Grilz, R. E. Redmann, and E. A. Driver. 1993. Standing crop, biomass allocation patterns and soil-plant water relations in Symporicarpos occidentalis Hook following autumn or spring burning. American Midland Naturalist 130: 106-115. SAS Publishing, 1999. Statview 5.0.1. SAS Institute, Cary, North Carolina. Umbanhowar, C. E. 1992. Abundance, vegetation, and environment of 4 patch types in a northern mixed prairie. Canadian Journal of Botany 70: 277-284. Umbanhowar, C. E. 1996. Recent fire history of the northern Great Plains. American Whisenant, S. G. 1990. Postfire population dynamics of Bromus japonicus. American Zar, J. H. 1999. Biostatistical analysis, fourth ed. Prentice Hall, Upper Saddle River, Table 1. Locations and descriptions of plots used to sample vegetation at Little Bighorn Battlefield in 1984-1986 and 2003. 45° 34.14’ N 107° 26.24’ W N80 E19 Along northwest fence, north of road to river 45° 34.09’ N 107° 26.30’ W N80 E18 Along northwest fence, north of road to river 45° 33.87’ N 107° 25.13’ W N67 E28 Calhoun Hill, inside road circle 45° 33.83’ N 107° 25.17’ W N67 E27 Calhoun Hill, just west of main road 45° 33.75’ N 107° 25.20’ W N66 E26 Northwest of road between Calhoun Hill and southern gate 45° 34.12’ N 107° 25.76’ W N76 E24 West/southwest of Custer Hill, east of path 45° 34.05’ N 107° 26.26’ W N78 E19 Northwest corner, s. of road to river 45° 34.02’ N 107° 26.23’ W N78 E18 Northwest corner, s. of road to river 45° 34.17’ N 107° 25.41’ W N74 E28 East/northeast of road between Custer and Calhoun Hills 45° 34.11’ N 107° 25.38’ W N73 E28 East/northeast of road between Custer and Calhoun Hills 45° 34.01’ N 107° 25.29’ W N71 E28 East/northeast of road between Custer and Calhoun Hills 45° 33.93’ N 107° 25.42’ W N71 E26 West/southwest of road between Custer and Calhoun Hills 45° 33.93’ N 107° 25.49’ W N71 E25 West/southwest of road between Custer and Calhoun Hills 45° 33.79’ N 107° 25.63’ W N70 E22 Central bottomland, side drainage to Deep Ravine 45° 33.68’ N 107° 25.71’ W N69 E20 Along north-facing slope south of Deep Ravine 45° 33.66’ N 107° 25.60’ W N68 E21 Along north-facing slope south of Deep Ravine 45° 33.69’ N 107° 25.43’ W N67 E23 On north-facing slope north/northwest of southern gate 45° 33.73’ N 107° 25.26’ W N66 E25 Northwest of road between Calhoun Hill and southern gate 45° 33.88’ N 107° 25.06’ W none Calhoun Hill, northeast of loop road, near C3 45° 33.93’ N 107° 26.14’ W N76 E18 Northwest corner, southeast of road to river 45° 33.99’ N 107° 26.01’ W N76 E20 Northwest corner, southeast of road to river 45° 33.97’ N 107° 25.80’ W N74 E22 Near path, half way from hdqts to Deep Ravine overlook 45° 33.83’ N 107° 25.80’ W N72 E21 Near end of path at Deep Ravine overlook 45° 33.70’ N 107° 25.80’ W N70 E19 On north-facing slope, south of Deep Ravine 45° 34.29’ N 107° 25.66’ W N78 E27 Near site of new Native American monument 1Prior to the start of vegetation data collection in 1984, an archaeological team had mapped the Battlefield on a 100-m grid, using short pieces of rebar that stood about 15 cm above the ground. Each rebar stake was covered with a yellow plastic cap marked with a north (N) by east (E) coordinate; the grid ran parallel to the northwestern and northeastern monument boundaries, rather than following true N-S, E-W compass directions. We used these rebar stakes to locate the southeastern corner of 19 of our 20 20x20-m vegetation sampling plots. By 2003, most of the plastic caps had deteriorated to the point where the grid marks were no longer legible. 2These plots were located on slopes and level uplands without drainages, in areas that had been burned in the 1983 fire that we judged comparable to those portions of the Battlefield spared by the fire. 3These plots were in swales and small drainages on the Battlefield that burned in the 1983 fire; there were no comparable sites on portions of the Battlefield spared by the 1983 fire. Table 2. Mean (standard error) of abundance of shrubs and succulents on twenty-five 400 m plots, of three habitat types, at the Little Bighorn National Battlefield in summer 2003, in terms of density (numbers per plot), percent canopy cover, and percent of subplots occupied (frequency). Abundance variable Unburned uplands Burned uplands Burned swales Kruskal-Wallis H (P) (n = 5 plots) (n = 16 plots) (n = 4 plots) ____________________________________________________________________________________________________________ Artemisia tridentata Percent frequency 6.7 (3.7) 4.6 (1.6) 1.7 (1.7) 1.3 (ns) Percent frequency 0 0 5.1 (5.0) 5.3 (0.07) Rhus trilobata Density 0.2 (0.2) 0.1 (0.1) 1.8 (1.0) 5.3 (0.07) Percent frequency 0 0 0 Rosa arkansana Density 0 0.2 (0.1) 37.0 (17.4) 17.5 (< 0.001) Percent cover 0 0.1 (0.1) 0.4 (0.2) 5.8 (0.06) Percent frequency 0 1.3 (0.9) 13.3 (7.2) 9.5 (0.09) Percent frequency 0 0 1.7 (1.7) 5.3 (0.07) Symphoricarpos occidentalis Density Percent frequency 0 0 21.7 (7.9) 17.1 (< 0.001) Percent cover 1.0 (0.7) 0.9 (0.4) 0.8 (0.6) 0.1 (ns) Percent frequency 1.3 (1.3) 3.3 (2.1) 3.4 (1.9) 1.2 (ns) aLevel to rolling uplands burned in the 1983 fire, in areas topographically similar to unburned portions of the Battlefield. bSwales and small drainages burned in the 1983 fire; there were no comparable areas spared by the fire. cPercent of 120 points where species canopy occurred; points were spaced at 0.5-m intervals along three 20-m transects on each plot. dPercent of 15 50x50-cm subplots on each plot in which the species was rooted. eNot statistically significant by Kruskal-Wallis H-test (P > 0.10). Table 3. Mean (standard error) of abundance of grasses and sedges on twenty-five 400 m plots, of three habitat types, at the Little Bighorn National Battlefield in summer 2003, in terms of percent canopy cover and percent of subplots occupied (frequency). Abundance variable Unburned uplands Burned uplands Burned swales Kruskal-Wallis H (P) (n = 5 plots) (n = 16 plots) (n = 4 plots) ____________________________________________________________________________________________________________ ___________________________________________________________________________________________________________ aLevel to rolling uplands burned in the 1983 fire, in areas topographically similar to unburned portions of the Battlefield. bSwales and small drainages burned in the 1983 fire; there were no comparable areas spared by the fire. cPercent of 120 points where species canopy occurred; points were spaced at 0.5-m intervals along three 20-m transects on each plot. dPercent of 15 50x50-cm subplots on each plot in which the species was rooted. eNot statistically significant by Kruskal-Wallis H-test (P > 0.10). fBased on work in 1984-86, this included a mix of A. spicatum and A. daystachyum, but these were not distinguishable in 2003 because they had not yet flowered at the time we sampled them. Table 4. Mean (standard error) of abundance of forbs on twenty-five 400 m plots, of three habitat types, at the Little Bighorn National Battlefield in summer 2003, in terms of percent canopy cover and percent of subplots occupied (frequency). Abundance variable Unburned uplands Burned uplands Burned swales Kruskal-Wallis H (P) (n = 5 plots) (n = 16 plots) (n = 4 plots) ____________________________________________________________________________________________________________ __________________________________________________________________________________________________________ aLevel to rolling uplands burned in the 1983 fire, in areas topographically similar to unburned portions of the Battlefield. bSwales and small drainages burned in the 1983 fire; there were no comparable areas spared by the fire. cPercent of 120 points where species canopy occurred; points were spaced at 0.5-m intervals along three 20-m transects on each plot. dPercent of 15 50x50-cm subplots on each plot in which the species was rooted. eNot statistically significant by Kruskal-Wallis H-test (P > 0.10). Table 5. Mean (standard error) of various measures of percent plant canopy cover and species richness on twenty-five 400 m plots, of three habitat types, at the Little Bighorn National Battlefield in summer 2003. Unburned uplands Burned uplands Burned swales Kruskal-Wallis H (P) (n = 5 plots) (n = 16 plots) (n = 4 plots) ___________________________________________________________________________________________________________ aLevel to rolling uplands burned in the 1983 fire, in areas topographically similar to unburned portions of the Battlefield. bSwales and small drainages burned in the 1983 fire; there were no comparable areas spared by the fire. cNot statistically significant by Kruskal-Wallis H-test (P > 0.10).

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