Assessment of Kootenai National Forest Vegetation Types with Potential for Silene Spaldingiiin the Tobacco Plains, Rexford Bench
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Assessment of Kootenai National Forest Vegetation Types with Potential for Silene spaldingii in the Tobacco Plains, Rexford Bench and Salish Range Foothills Prepared for: Kootenai National Forest Supervisor’s Office By: S. V. Cooper Montana Natural Heritage Program Natural Resource Information System Montana State Library December 2003 Assessment of Kootenai National Forest Vegetation Types with Potential for Silene spaldingii in the Tobacco Plains, Rexford Bench and Salish Range Foothills Prepared for: Kootenai National Forest Supervisor’s Office Agreement Number: 01-CS-11011400-021 By: S. V. Cooper © 2003 Montana Natural Heritage Program P.O. Box 201800 • 1515 East Sixth Avenue • Helena, MT 59620-1800 • 406-444-5354 ii This document should be cited as follows: Cooper, S.V. 2003. Assessment of Kootenai National Forest Vegetation Types with Potential for Silene spaldingii in the Tobacco Plains, Rexford Bench and Salish Range Foothills. Unpublished report to Kootenai National Forest, Supervisor’s Office. Montana Natural Heritage Program, Helena, MT. 33 pp. plus appendices. iii EXECUTIVE SUMMARY Silene spaldingii (Spalding’s catchfly) has species invasion); it is uncertain whether this relatively recently (October 10, 2001) been listed disturbance could have resulted in population by the U. S. Fish and Wildlife Service as extirpation. “Threatened” throughout its entire range. The Tobacco Valley of northwestern Montana harbors The rough fescue (Festuca campestris) grasslands the largest known population (on TNC’s Dancing found here are compositionally unlike those Prairie Preserve) as well as several satellite occurring anywhere else due to grazing effects and populations of this species. Locating additional coarse substrates that combine to favor some populations of this species, especially on Federal graminoids more typically associated with the Great lands where appropriate management could be Plains. This combination of environment and instituted, is a conservation priority. The Montana vegetation has resulted in some unique communities Natural Heritage Program contracted with the not described elsewhere. New provisionally Kootenai National Forest to survey their land recognized grassland associations have been having the greatest probability of S. spaldingii described. The presence of antelope bitterbrush populations. Putatively appropriate habitat, including (Purshia tridentata) in combination with both mesic grasslands, shrublands, and open woodlands ponderosa pine (Pinus ponderosa) and F. was inventoried, with grasslands receiving the most campestris was additionally recognized in new thorough search. No new populations of S. shrubland and woodland plant associations spaldingii were located but, in the course of (provisional). inventory, a number of plant communities (associations) were sampled and described. Although our inventory was confined to U. S. Forest Service lands, it was abundantly obvious that The communities of this landscape (Tobacco Valley this is a landscape under siege from alien plant vicinity and immediate foothills/mountainous terrain species (whether classed weedy or not) and that to the south) have not been previously described/ Dancing Prairie Preserve and U. S. Forest Service documented, though limited sampling has occurred. lands will have to be the repositories of native A combination of coarse-textured outwash biological diversity. While not explicitly evaluated, substrates and a relatively dry precipitation regime we note that a USFS prescribed burning program results in grasslands and shrublands where was achieving its intended effect of removing trees woodlands and forests might be expected. encroaching on grasslands and shrublands. The Environments supporting mesic grasslands where agency should pay particular attention to invasive S. spaldingii would have the greatest likelihood of species of alien grasses, particularly smooth brome occurring have experienced the greatest (Bromus iermis); these grasses could be as disturbance (habitat conversion/destruction, alien threatening to diversity as noxious weeds. iv ACKNOWLEDGMENTS Thanks to Cathie Jean (former Ecology Program expertise, and editing. Terry Kenney at MTNHP Manager, MTNHP) and Dan Leavell (Forest and her US Forest Service counterpart, Nancy Ecologist, Kootenai National Forest) for conceiving, Kmonk, produced excellent working maps and initiating and guiding this project. Greg Kudray associated materials that expedited the field work. (Ecology Program Manager) is appreciated for Coburn Currier contributed valuable suggestions applying his editorial skills. Thanks to Marc Jones improving the manuscript’s readability and also (MTNHP wetlands ecologist) for providing field formatted it into MTNHP style. Errors of omission assistance, geographic information systems and commission rest with the author. v TABLE OF CONTENTS Introduction ................................................................................................................................................... 1 Environmental Setting ................................................................................................................................... 2 Methods ........................................................................................................................................................ 4 Community Level Inventory................................................................................................................... 4 Species Level Inventory......................................................................................................................... 4 Results .......................................................................................................................................................... 6 Plant Species .......................................................................................................................................... 6 Grassland / Woodland Landscape .......................................................................................................... 7 Plant Communities ............................................................................................................................... 10 Discussion/Conclusions .............................................................................................................................. 12 Silene spaldingii ................................................................................................................................. 12 Plant Communities ............................................................................................................................... 12 Literature and References Cited (Includes references cited in Appendix A, B, and D) ........................... 16 Appendix A. Global / State Rank Definitions Appendix B. Descriptions of Study Area Plant Associations with the Potential of Supporting Silene spaldingii Populations Appendix C. Photographs of Representative Vegetation Types (Associations) on Study Area Sites Appendix D. Descriptions of Alliances and Plant Associations LIST OF FIGURES Figure 1. Study Area, showing locations of vegetation survey plots ........................................................... 8 LIST OF TABLES Table 1. Plant, lichen, and animal species of special concern potentially occurring within the greater Tobacco Plains, Rexford Bench, Salish Range foothills landscape ................................................ 5 Table 2. Plant Associations/Communities found within Kootenai N. F. study area .................................. 11 vi INTRODUCTION The Tobacco Plains, Rexford Bench and northern Nature Conservancy’s Montana Natural Heritage foothills of the Salish Range constitute an area that Program was initiated to address both S. has received only cursory botanic/vegetation spaldingii populations and their potential habitat, exploration, though the wetlands and associated generally, though not exclusively, perceived to be peatlands of the adjoining forested landscape have mesic grasslands. been extensively inventoried and are in the process of being intensively investigated. The Nature This study has two goals: Conservancy and others recognized the potential of some grassland habitat in this area to support a 1. Inventory for Silene spaldingii in declining species, Columbian sharp-tailed grouse appropriate grassland habitats and (Tympanuchus phasianellus columbianus) and a contiguous woodlands where trees have preserve, Dancing Prairie, was established to ostensibly recently encroached on protect this habitat in the face of burgeoning grassland habitat. This inventory was development and incompatible land use. conducted over two years owing to the Serendipitously, this preserve contained high quality ability of S. spaldingii to remain dormant grasslands and a population of Spalding’s catchfly under adverse growing conditions. (Silene spaldingii), a plant recently listed by the U.S. Fish and Wildlife Service as threatened. If 2. Assess grassland and woodland these gems of conservation existed in the center of conservation in the Tobacco Plains, a disturbed landscape, then what conservation Rexford Bench and Salish Range northern targets might be harbored on National Forest lands foothills. This will include 1) identifying, at the periphery of this threatened landscape? describing, and evaluating the habitat Regardless of whether these Forest Service lands quality of surveyed areas, 2) assessing support sensitive native species,