MONTANA STATE This **cover" page added by the Internet Archive for formatting purposes Ni lupCd STATE DOCUMENTS COLLECTION SFP0 41992 MONTANA STATE LIBRARY 1515 E. 6th AVE HELENA, MONTANA 59S20 UPDATE TO THE REPORT ON THE CONSERVATION STATUS OF Arabis f ecunda . A CANDIDATE THREATENED SPECIES Taxon name: Common najtie: Family: State where taxon occurs: Current Federal status: Recommended Federal status: Author of update: Original date of report: Date of most recent revision; Arabis fecunda Rollins Sapphire rockcress Brassicaceae (Cruciferae] U.S.A., Montana USFWS Notice of Review, Category 2 USFWS Notice of Review, Category 2 Lisa Ann Schassberger November 15, 1985 January 29, 1990 Individual to whom further information and comments should be sent: J. Stephen Shelly Montana Natural Heritage Program State Library Building 1515 E. 6th Avenue Helena, MT 59620 This is an abridged report For the full report please contact: The Montana Natural Heritage Program 1515 E Sixth Ave Helena, Montana 59620 406-444-3009 New Information 21. Record of revisions: 29 January 1990; Lisa Ann Schassberger; Topics: I.I.D.; I.2.B.b.; I.5.A.; I. 5. B. I.e.; I. 6. A.; I.6.B.l.b.; I. 6, B. I.e.; I.6.B.4.; I.6.C.I.; I.6.C.3.; I.6.C.4.; I,6.C.7.; 1. 7. A.; I.7.B.I.; I.7.B.2.in.; I.7.D.4.a.; I.8.C.2.b.; I. 9. A.; I.9.B.; I.ll.A.l.; 11.12.; II. 13. A.; II.13.B.; II. 15. A. 1.; II. 15. A. 2.; II.15.B.; 11.16; III.17.C.1.; III. 17. D.; III. 18, Note: Within the text, numbers in parentheses following site names are the three-digit occurrence numbers of sites tracked by the Montana Natural Heritage Program. I.l.D. History of knowledge of taxon: One additional population of Arabis fecunda was discovered at Cattle Gulch (013) in the Pioneer Mountains, Beaverhead County, Montana, during survey work in 1989. This brings the total number of known populations of A. fecunda to 13. I.2.B. National. b. Other current formal status recommendations: Arabis fecunda is currently included on the Watch list in Region 1 (Northern Region) of the U.S. Forest Service. Watch plants include those species, subspecies or varieties that are not currently known to occur on National Forest land, but which are suspected to occur on such lands owing to the presence of suitable habitat. Also, these are plants for which there is concern for population viability within a given state. If found on National Forest lands, these taxa would be designated as sensitive (U.S. Department of Agriculture 1988) . Since the establishment of list, A. fecunda was confirmed from five locations on the Beaverhead National Forest. Thus, the status should be changed to sensitive on the U.S. Forest Service list. I. 5. A. Geographical range: The newly discovered population of A. fecunda at Cattle Gulch (013) is just southwest of Divide in the Pioneer Mountains, Beaverhead County, Montana. This population is approximately 2.5 miles east of the population at Canyon Creek (Oil) . Arabis fecunda is known only from southwestern Montana. The global distribution for this species is shown on Map 1, p. 3. I.5.B.I. Populations currently known extant: e. Montana: Information on the newly discovered Cattle Gulch population (013) is found on p. 4; the exact location is provided on a map, p. 5. Additional information was gained on the Quartz Hill (005) and Canyon Creek (Oil) sites. Updated occurrence records and maps for these sites are included on pp. 6-8. Information on the other 12 known populations of A. fecunda may be found in Lesica (1985) and Schassberger (1988) . I. 6. A. Concise statement of general environment and habitat. The Cattle Gulch population occurs in dry, gravelly calcareous soil, on steep southwest-facing slopes, at 6,200 feet in elevation. I.e.B.l.b. Regional macroclimate: The long-term weather station nearest to the newly discovered population in the Pioneer Mountains is at Divide, approximately 3.5 miles northeast of the site, at 5,395 ft. in elevation. For the period from 1951-1980, the July mean temperature was 63.3 °F, the January mean was 19.1 °F, and the average annual precipitation was 12.39 in. (U.S. Department of Commerce 1982) . I. 6. B. I.e. Local microclimate. The climate at Cattle Gulch is probably similar to that of Divide. However, this site is probably somewhat cooler and may receive more precipitation, as it is 1,000 ft. higher in elevation. I.6.B.4. Physiographic and topographic characteristics: The Cattle Gulch (013) population occurs on soils derived from the Madison Limestone Formation, comprised of metamorphosed limestone and sandstones, and the Threeforks Formation, comprised of grayish-brown argillaceous limestone (Richards and Pardee 1925) . This A. fecunda population is on steep, southwest-facing ARABIS FECUNDA SAPPHIRE ROCKCRESS Global rank: G2 Forest Service status: WATCH LIST State rank: S2 Federal Status: C2 Element occurrence code: PDBRA06290 . 013 Survey site name: CATTLE GULCH County: Beaverhead Latitude: 454133 Longitude: 1124712 USGS quadrangle: CATTLE GULCH Township-range: 002S010W Section: 01 Township-range comments: NW4 , NE4SW4, Section 2, NE4 ; TISRIOW: Section 36, SW4 Survey date: 1989-06-07 Elevation: 6200 First observation: 1989 Slope/aspect: 15-35% / S , SW Last observation: 1989-06-07 Size (acres) : 160 Location: PIONEER MOUNTAINS, CATTLE GULCH, 1.0-1.65 AIR MILES NORTHWEST OF CONFLUENCE OF CATTLE GULCH AND CANYON CREEK, CA. 7 AIR MILES NORTHWEST OF MELROSE, MT. Element occurrence data: 127 PLANTS COUNTED (84 FLOWERING, 4 3 STERILE) ; FOUR SUBPOPUIATIONS ; SLOPES LARGELY UNDISTURBED, ALTHOUGH THERE HAS BEEN SOME PAST GRAZING IN THE BOTTOM OF CATTLE GULCH. General site description: IN DRY, GRAVELLY CALCAREOUS SOILS ON STEEP SLOPES; CERCOCARPUS LEDIFOLIUS/AGROPYRON SPICATUM TYPE, WITH ARTEMISIA FRIGIDA, PHYSARIA GEYERI , LINUM PERENNE , SENECIO CANUS, GUTIERREZIA SAROTHRAE, CYMOPTERUS BIPINNATUS, OPUNTIA POLYACANTHA. Land owner/manager: BEAVERHEAD NATIONAL FOREST, WISE RIVER RANGER DISTRICT Comments: VOUCHER - SHELLY, J.S. (1512), 1989, (MONTU) ; SITE SURVEYED WITH DR. FRANK SCHITOSKEY, USFWS . Information source: SHELLY, J.S. 1989. FIELD SURVEYS IN BEAVERHEAD COUNTY, 5-9 Element Occurrence Record - Arabis fecunda Montana Natural Heritage Program slopes, at 6,200 ft. in elevation. I.6.C.I. Vegetation, physiognomy and conununity structure: The vegetation associated with A. fecunda at the Cattle Gulch (013) site would be classified as a Cercocarpus ledifolius (curly-leaf mountain mahogany) / Agropyron spicatum (bluebunch wheatgrass) habitat type as described by Mueggler and Stewart (1980) . I.6.C.3. Species associated with Arabis fecunda at Cattle Gulch (013) include Artemisia frigida (fringed sagewort) , Gutierrezia sarothrae (broom snakeweed), Physaria geyeri (Geyer's twinpod) , Linum perenne (blue flax) , Senecio canus (wooly groundsel) , Cymopterus bipinnatus (fernleaf spring parsley) and Opuntia polyacantha (plains pricklypear) . I.6.C.4. Dominance and frequency of this taxon in the community type: The canopy cover of A. fecunda at Cattle Gulch (013) is quite low (less than 1%) , which is somewhat lower than other known populations. I.6.C.7. Other endangered, threatened, rare, or vulnerable species occurring in the habitat of this taxon: Mimulus suksdorf ii and Astragalus platytropis, two plants of limited distribution in Montana occur with Arabis fecunda at Cattle Gulch. Mimulus suksdorf ii is currently known from only one other location in southwestern Montana. Astragalus platytropis is known from six other locations, also in southwestern Montana. I. 7. A. General svumnary of population biology of the taxon: There are about 127 A. fecunda plants in the Cattle Gulch (013) population, in an area covering 60 acres. I.7.B.I. Known Populations: One new population of A. fecunda was discovered during the 1989 field season. This brings the total number of known populations to 13, all of which occur in Montana. Nine of these populations occur along the north and east flanks of the Pioneer Mountains, Beaverhead and Silver Bow counties, while the other four populations are found along the western foothills of the Sapphire Range in Ravalli County. I.7.B.2. General demographic details of each population. m. Cattle Gulch 1. Area: Four subpopulations covering 60 acres. 2. Number and size of plants: 127 plants counted, ca. 65 % in flower (1989) . 3. Density: Sparse. 4. Presence of dispersed seed: Unknown . 5. Evidence of reproduction: Presence of flowers and fruit. 6. Evidence of expansion/contraction: None. I.7.D.4. Seed biology. a. Amount and variation of seed production: Information from permanent transects at Birch Creek (004) and Charleys Gulch (001) indicate that fruit production is strongly related to climatic trends and, perhaps to a lesser extent, interspecific competition. See Appendix B in Schassberger (1988) , and Appendix A of this report (p. 16) . The effects of Centaurea maculosa invasion on the fecundity of A. fecunda are also discussed in Hamilton and Mitchell-Olds (1989) . In 1989, transects were established at two sites (Lime Gulch (012) and Canyon Creek (Oil)) in the Pioneer Mountains, in order gain more information on the life history of this species in areas not invaded by spotted knapweed, Centaurea maculosa (Appendix B, p. 17) . This study is designed to compliment research on two populations (Birch Creek (004) and Charleys Gulch (001)) located on the western flanks of the Sapphire Mountains. The data collected in 1989 from the Pioneer Mountains indicate that fecundity was higher at Canyon Creek (Oil) than at Lime Gulch (012) . The number and percent of plants fruiting, and the number of fruits per plant and 11 per inflorescence, were higher at Canyon Creek. The number of seeds per fruit was quite similar for each site (Appendix B, p. 17) . Although the differences in fecundity are interesting, no conclusions can be drawn yet. The Lime Gulch (012) population is approximately 1,000 feet lower in elevation than Canyon Creek (Oil) , and is located on the lower eastern flanks of the Pioneer Mountains in the rain shadow of some of the highest peaks of the range. Thus, it is likely to receive substantially less precipitation and have warmer temperatures than the Canyon Creek population. These site differences influence the phenology of the populations. The data indicates that there needs to be at least a one to two week delay in reading the Canyon Creek transects, in order to obtain data comparable to Lime Gulch (Appendix B, p. 17). I.8.C.2. b. Interspecific: Density and fecundity of Arabis fecunda populations may be influenced by the presence and abundance of Centaurea maculosa (spotted knapweed) . Reports from an ongoing study of the interactions between these two species from sites in Ravalli County is contained in Appendix B of Schassberger (1988) , and in Appendix A of this report (p. 16) . See also Hamilton and Mitchell-Olds (1989). I. 9. A. General nature of ownership: The Cattle Gulch (013) site is on U.S. Forest Service lands. I.9.B. Specific landowners: 1. USDA Forest Service Beaverhead National Forest 610 N. Montana Street Dillon, MT 59725 I.ll.A.l. Present or threatened destruction, modification, or curtailment of habitat or range: The A. fecunda population at Cattle 12 Gulch is in largely undisturbed habitat. Although some grazing does occur in the area, it appears to be restricted to the lower, more gently sloping hillsides, below the population. 11.12. General assessment of vigor, trends and status: All 13 A. fecunda populations occur within a radius of ca. 47 miles. Centaurea maculosa (spotted knapweed) is currently not a threat to populations along the flanks of the Pioneer Range, but appears to be impacting the sites along the foothills of the Sapphire Range. See Appendix B Schassberger (1988) , and Appendix A of this report (p. 16) . Reproductive output of the A. fecunda population at Cattle Gulch appears to be normal, but has fewer individuals than other populations nearby. II. 13. A. Recommendation to U.S. Fish and Wildlife Service: It is recommended that Arabis fecunda be retained as a Category 2 species, until threats to populations can be more fully evaluated. II.13.B. U.S. Forest Service: Arabis fecunda is now known to occur on lands administered by the U.S. Forest Service. Thus, it should be placed on the list of sensitive species in Region 1 for Montana. II. 15. A. 1. Recommendations regarding present or anticipated activities: The effects of mining or increased grazing in areas supporting populations of Arabis fecunda should be assessed before any new management actions are implemented. Although spotted knapweed (Centaurea maculosa) is not currently a problem in the Pioneer Mountains, its eventual dispersal into the area should be monitored, as this species appears to have a negative impact on many plant species, including Arabis fecunda. 2. Areas recommended for protection: Canyon Creek (Oil) : Large representative population of Arabis fecunda located at a higher elevation site on U.S. Forest Service lands in the East Pioneer Mountains. 13 Recommendation: Site should be proposed for special designation. Lime Gulch (012) : Large representative population at a lower elevation, on very distinctive soils, located on the lower eastern flanks of the East Pioneer Mountains. This population is on Forest Service lands, and a close equivalent to sites in the foothills of the Sapphire Range (which are threatened by spotted knapweed invasion) . Recommendation: Site should be proposed for special designation. Quartz Hill (005) : This site supports a good population of A. fecunda, and populations of Penstemon lemhiensis (Lemhi penstemon) and Claytonia lanceolata var. f lava (yellow springbeauty) occur nearby. Both of these plants are also USFWS Category 2 taxa, and are included on the U.S. Forest Service Region 1 list of sensitive species. Recommendation: Site should be proposed for special designation. Monitoring activities: Monitoring should be continued at all four current study sites, to gain valuable long-term life history information. III. 17. C. 1. Surveys: J. Stephen Shelly, Montana Natural Heritage Program: 8 May 1986 (001; Charleys Gulch) 19-20 May 1987 19-20 May 1988 1-3 June 1988 24-25 May 1989 6-9 June 1989 Peter Lesica, The Nature Conservancy: 8 May 1986 (001; Charleys Gulch] 27-30 May 1986 19-20 May 1987 19-20 May 1988 24-25 May 1989 14 Lisa A. Schassberger, Montana Natural Heritage Program: 1-3 June 1988 6-7 June 1988 13-15 June 1988 6-9 June 1989 III. 17. D Knowledgeable individuals: Lisa Schassberger and J. Stephen Shelly Montana Natural Heritage Program State Library Building 1515 E. 6th Ave. Helena, MT 59620 Peter Lesica Division of Biological Sciences University of Montana Missoula, MT 59812 III. 18. Summary of materials on file: All detailed field forms, maps and color slides are on file at the office of the Montana Natural Heritage Program, Helena, MT. Herbarium vouchers for Montana populations are deposited at the University of Montana Herbarium (MONTU) Missoula. 15 Literature Cited Hamilton, M.B., and T. Mitchell-Olds. 1989. Population biology of Arabis fecunda. a rare endemic. 1. Directional selection and interspecific competition. Evolution (In review) . Lesica, P. 1985. Report on the conservation status of Arabis fecunda, a potential candidate species. Unpublished report to the U.S. Fish and Wildlife Service, Denver, Colorado. 18 pp. Mueggler, W.F., and W.L. Stewart. 1980. Grassland and shrubland habitat types of Western Montana. Intermountain Forest and Range Experiment Station, Ogden, Utah. 154 pp. Richards, R.W., and J.T. Pardee. 1925. The Melrose Phosphate Field, Montana. U.S.G.S. Bull. 780: 1-32. Schassberger, L.A. 1988. Update to the report on the conservation status of Arabis fecunda, a candidate threatened species. Unpublished report to the U.S. Fish and Wildlife Service, Denver, Colorado. 36 pp. U.S. Department of Agriculture, Forest Service. 1988. Sensitive Plant Field Guide to Montana. U.S. Forest Service, Northern Region, Range, Air, Watershed, and Ecology Unit, Missoula, Montana. U.S. Department of Commerce. 1982. Monthly Normals of Temperature, Precipitation, and Heating and Cooling Degree Days 1951-80. National Oceanic and Atmospheric Administration, Climatography of the United States No. 81. 23 pp. 16 Appendix A 17 Appendix B THE ECOLOGY OF ARABIS FECUNDA: LONG-TERM MONITORING AND SPOTTED KNAPWEED REMOVAL STUDIES 1989 PROGRESS REPORT Peter Lesica The Nature Conservancy- Montana Field Office P.O. Box 258 Helena, MT 59624 and J. Stephen Shelly Montana Natural Heritage Program State Library Building 1515 E. 6th Ave. Helena, MT 59620 September 1989 INTRODUCTION In order to adequately protect populations of an organism, it is necessary to understand its life history and population dynamics (Massey and Whitson 1980, Sutter 1986, Palmer 1987). In addition, many rare species are threatened by interactions with non-native species that have been introduced into their habitat (Drake 1988) . It is important to understand the nature of these interactions in order to protect populations of rare species from extinction. Sapphire rockcress (Arabis fecunda Rollins) is a rosette- forming perennial in the Mustard Family (Brassicaceae) . This recently described species (Rollins 1984) is endemic to highly calcareous, azonal soils in the foothills of the Sapphire Range in Ravalli County and in the Pioneer Range in Beaverhead and Silver Bow counties, Montana (Lesica 1985, Schassberger 1988). Arabis fecunda occurs on eroding slopes with low vascular plant density. Often these sites have a relatively high cover of cryptogamic soil crust. In Ravalli County, populations of Arabis fecunda are thought to be threatened by livestock grazing and encroachment by an aggressive exotic weed, spotted knapweed (Centaurea maculosa) (Lesica 1985) . This paper is a progress report on two studies being conducted on populations of Arabis fecunda in Ravalli County. The studies and their purposes are: Study 1. Long-term monitoring of Arabis fecunda populations. Purpose: Determine important life history attributes, and determine trends in overall recruitment and mortality. Study 2. Spotted knapweed removal study. Purpose: Determine the effects of spotted knapweed competition on the reproductive performance and survivorship of Arabis fecunda. METHODS Study Areas We conducted our studies at two sites in Ravalli County, Montana: Charleys Gulch and Birch Creek. The Charleys Gulch site is on a steep, eroding, southwest-facing slope along the gulch at an elevation of ca. 5,000 ft. (T6N R19W S29, NWl/4). The Birch Creek site is on a steep, eroding, southeast-facing slope above the creek at an elevation of ca. 4,700 ft. (T7N R19W S16, NWl/4) . More complete descriptions of the study sites can be found in Lesica (1985) and Schassberger (1988) . Long-term Monitoring Study In May, 1987, we established permanent belt transects of 12 adjacent m^' plots at each site following the methods outlined in Lesica (1987). Individual Arabis fecunda plants were mapped and recorded using the following system: S - Seedling R - indicates the number of rosettes per plant I - indicates the total number of inflorescences (stems) per plant F - indicates the total number of fruits produced by the plant Thus, a plant with two rosettes, three stems and a total of nine fruits would be recorded as R1-I3-F9. Seedlings were recognized by their small size (< 15 mm diameter). Many single cpr multiple rosette plants may also be first-year plants. In addition, we noted the presence of recently disturbed soil and evidence of livestock trampling. We did not record seedling-size plants at the Birch Creek site in 1987. In 1989 we collected 50 randomly selected fruits from different individual at Charleys Gulch, and 25 fruits at Birch Creek. Each fruit was hand-dissected, and the number of seeds in each was recorded. We read the transects on May 19-20, 1987 and 1988 and May 24-25, 1989. Population density and fecundity data are presented in Table 1. Spotted Knapweed Removal Study In May, 1987, we established two permanent belt transects consisting of 10 adjacent m^ plots at each of the study sites following the methods of Lesica (1987). Transects were placed in areas with relatively heavy spotted knapweed infestations. Individual Arabis fecunda plants were mapped and recorded as in the long-term monitoring study. For each transect, we removed the spotted knapweed from five randomly selected plots by carefully cutting the plants below the root crown with a sharp knife. Spotted knapweed was removed from plots 2,4,5,8, and 9 at Birch Creek and from plots 1,4,5,8, and 9 at Charleys Gulch. We did not record seedlings at the Birch Creek site in 1987. Ocular estimates of percent canopy cover of spotted knapweed were made for treatment and control plots each year. We read the transects on May 19-20, 1987 and 1988 and May 24-25, 1989. Data on percent canopy cover of spotted knapweed are presented in Table 2 ; performance parameters for A. fecunda are shown in Table 3. Data Analysis Population growth rate was calculated for each long-term monitoring study site in 1988 and 1989 by taking the increase in individuals over the previous year and dividing by the number of individuals present in the plot the previous year. Negative growth rates reflect a decreasing population size. Discussion I. Long-term monitoring studies 1. The severe drought that occurred in 1988 appears to have influenced total fruit production at both Charleys Gulch and Birch Creek (Table 1) . During that year, the percentages of fruiting plants reached the lowest recorded levels. However, over the three study years, at both sites, there has been an increase in the fecundity (# fruits/fruiting plant) of the reproductive individuals. 2. The slight negative population growth rate at the Charleys Gulch site may be due, in part, to the impacts of cattle trampling, which was very evident at this site in both 1988 and 1989. II. Spotted knapweed removal studies 1. Yearly removal of spotted knapweed from randomly selected plots in the study transects has resulted in a decrease (but not eradication) in the mean percent canopy cover of spotted knapweed in those plots, at both Charleys Gulch and Birch Creek (Table 2) . 2. At Charleys Gulch, an increase in plant densities occurred in the spotted knapweed removal plots over the three-year study period (Table 3) . At Birch Creek, a drastic increase was detected in 1988, followed by a decrease in 1989 (Table 4) . In the control plots, densities remained fairly constant at Charleys Gulch, and decreased slightly in 1989 at Birch Creek. These data suggest that reduction of interspecific competition from spotted knapweed may allow increased establishment of A. fecunda plants. The population growth statistics reflect these changes. 3. The fecundity parameters were apparently heavily influenced by the drastic climatic fluctuations during the three-year study period. To fully assess the potential influence of spotted knapweed competition on fecundity, additional transect readings over several more years are needed. Table 1. Population density and fecundity data for Arabis fecunda in long-term monitoring transects, 1987-1988 Density (plants/m'^ ) Population growth # plants fruiting % plants fruiting # fruits per fruiting plant # fruits per inflorescence % plants with more than one rosette one-rosette plants with fruit multi-rosette plants with fruit Birch Creek 4.8 4.6 4.9 Charlevs Gulch 1987 1988 1989 6.5 6.0 5.5 1988 1989 0.14 0.05 -0.08 -0.08 1987 1988 1989 20 7 32 33 11 24 1987 1988 1989 35% 11% 47% 42% 15% 36% 1987 1988 1989 3.8 14.0 22.0 5.1 8.8 15.8 1987 1988 1989 2.2 5.2 6.8 2.1 3.0 3.9 1987 1988 1989 9% 8% 9% 27% 38% 30% 1987 1988 1989 29% 12% 45% 37% 22% 35% 1987 1988 1989 83% 0% 67% 57% 4% 40% Percent canopy cover of spotted knapweed ( C en t < removal transects in 1987 (before spotted knapweed removal), 1 and 1989. An asterisk (*) indicates plots from which spotted knapweed was removed; remaining plots are controls. Charleys Gulch #2 Control Remo va I Mean Mean 1987 20 25 20 25 2! 1988 5 20 28 15 If 1989 25 33 23 20 23 30 25 30 25 23 18 35 10 28 30 30 rch Creek #2 Control Remo\ Mean Me£ 1987 30 35 35 30 33 38 28 23 23 28 1988 30 20 30 30 20 30 15 30 30 20 1989 28 10 AO 15 23 15 20 ible 3. Performance parameters for A r a b i s f e c u n d a in spotted knapweed removal (n=5) and control (n=5) plots at Charleys Gulch (mean=SD). 1987 Removal Contro Density ( p I a n t s / p I o t ) 12.8 + 3.9 Fruiting plants/plot 5.8+2.7 % plants fruiting New plants Dead plants Population growth # fruits/plot # inflorescences/plot 12.2+6.7 Fruits/ inflorescence 2.2+0.3 R emo va I 14.2 + 3.6 14.4 + 3 .3 4.6 + 2.6 0.4 + 0 .5 39.3+13.0 32.5+17.6 2.4+3.2 4.2+2.6 2.6+3.6 0.15 26.8+17.0 18.6 + 6. 7 4 .6 + 6 .8 8.4 + 3 .8 1.0+1.4 2.4+0.5 4.5+0.7 if lorescence/frui t ing plant 2.1+0.5 1 . 1 2.5+0.7 1989 Control Removal Control 14 .0+4.2 19.4+5.8 13.4+3.7 0.4 + 0.9 6.4 + 4 .2 5.4 + 2.5 4 . 0+8 .9 30.6+16.6 39.9+13.0 3.0+2.9 7.0+3.2 2.6+1.3 3.2+2.0 2.0+2.0 3.2+1.5 -0.02 0.41 -0.08 3 .4 + 7.6 104 .8 + 61 .9 82 .0 + 38. 1 1.0 + 2.2 27.6+17.7 21. 2 + 9. 7 3.4+0.0 3.9+0.4 3.8+0.3 2.5+0.0 4.4+1.1 4.4+2.2 Performance parameters for A r a b i s f e c u n d a in spotted knapweed removal (n=5) and control (n=5) plots at Bi Creek (mean+SD). 1987 1988 Removal Control Removal Control Removal Control Removal Density ( p I a n t s / p I o t ) 16.0 + 3.9 21.2 + 6.5 58.0 + 59.2 24.0 + 3.7 32.6+12.9 Fruiting plants/plot 8.8+2.9 8.0+A.5 1.2+1.3 1.4+2.1 11.2+5.3 % plants fruiting 54.7+12.1 35.7+12.3 4.6+6.2 5.5+7.9 33.7+9.7 New plants 50.4+60.3 13.6+8.6 16.8+6.3 Dead plants 11.4+5.2 10.8+5.8 42.2+50.4 Populationgrowth 2.67 0.27 -0.12 # fruits/plot 55.6+26.4 39.2+16.9 18.2+18.6 8.0+10.7 348+169 # inflorescences/plot 22.2+6.6 18.8+9.2 3.6+4.6 1.8+2.9 41.6+18.4 Fruits/ inflorescence 2.4+0.6 2.4+1.1 6.5+3.1 5.9+2.2 8.6+2.9 Inflorescence/fruiting 2.2+0.6 2.6+1.0 2.7+0.9 1.1+0.2 3.8+0.6 plant Control 17.2+10.3 5.4+4.7 36.2+17.9 7.8+5.4 14.6+5.9 -0.28 139+168 22 .0 + 23.2 5.7+1.9 3.5+1.5 LITERATURE CITED Drake, J. A. 1988. Biological invasions into nature reserves. Trends in Ecology and Evolution 3: 186-187. Lesica, P. 1985. Report on the conservation status of Arabis fecunda, a potential candidate species. Submitted to the U.S. Fish and Wildlife Service, Office of Endangered Species, Denver, CO. Lesica, P. 1987. A technique for monitoring nonrhizomatous, perennial plant species in permanent belt transects. Natural Areas Journal 7: 65-68. Massey, J. R. and P. D. Whitson. 1980. Species biology, the key to plant preservation. Rhodora 82: 97-103. Palmer, M. E. 1987. A critical look at rare plant monitoring in the United State. Biological Conservation 39: 113-127. Rollins, R. C. 1984. Studies in the Cruciferae of western North America II. Contributions to the Gray Herbarium 214: 1-18. Schassberger, L. A. 1988. An update of the report on the conservation status of Arabis fecunda, a candidate threatened species. Report to the U.S. Fish and Wildlife Service, Office of Endangered Species, Denver, CO. Sutter, R. D. 1986. Monitoring rare plant species and natural areas - ensuring the protection of our investment. Natural Areas Journal 6: 3-5. DEMOGRAPHIC MONITORING OF ARABIS FECUNDA IN THE PIONEER RANGE 1989 ESTABLISHMENT REPORT Peter Lesica The Nature Conservancy Montana Field Office P.O. Box 258 Helena, MT 59624 and J. Stephen Shelly Montana Natural Heritage Program State Library Building 1515 E. 6th Ave. Helena, MT 59620 December 1989 INTRODUCTION In order to adequately protect populations of an organism, it is necessary to understand its life history and population dynamics (Massey and Whitson 1980, Sutter 1986, Palmer 1987). In addition, many rare species are threatened by interactions with non-native species that have been introduced into their habitat (Drake 1988) . It is important to understand the nature of these interactions in order to protect populations of rare species from extinction. Sapphire rockcress (Arabis fecunda Rollins) is a rosette- forming perennial in the Mustard Family (Brassicaceae) . This recently described species (Rollins 1984) is endemic to highly calcareous, azonal soils in the foothills of the Sapphire Range in Ravalli County, and in the Pioneer Range in Beaverhead and Silver Bow counties, Montana (Lesica 1985, Schassberger 1988) . Arabis fecunda generally occurs on steep, often eroding slopes with low vascular plant density. In Ravalli County, populations of A. fecunda are thought to be threatened by livestock grazing and encroachment by an aggressive exotic weed, spotted knapweed (Centaurea maculosa) (Lesica 1985, Schassberger 1988) . In Silver Bow and Beaverhead counties, populations may be threatened by mining activity and livestock grazing. This report documents the establishment of demographic monitoring transects for Arabis fecunda at two sites in the Pioneer Range, on Beaverhead National Forest lands. STUDY SITES I. Lime Gulch Location: Five miles west of Interstate Highway 15, on the north side of Birch Creek Road, approximately 1/4 mile up Lime Gulch from the road; T5S RlOW Sec 14; ca. 6,200 ft elevation. a. South Transect Location: East-facing slope on the west side of the gulch, ca. 20 m up from the bottom. 98 degrees from the start pin to the summit of Limestone Mountain; 2 04 degrees to the summit of the grassy mountain south of Birch Creek Road. The start pin is next to an old juniper stump. Line bearing: 21 degrees Slope: 16 degrees Aspect: 165 degrees Instructions: Read transect south to north. b. North Transect Location: West-facing slope on the east side of the gulch, ca. 5 in above the bottom. 209 degrees from start pin to the summit of the bald hill with patches of trees; 17 degrees to the base of the Douglas fir snag near the bottom of the gulch. Line bearing: 178 degrees Slope: 22 degrees Aspect: 274 degrees Instructions: Read transect north to south. II. Canyon Creek Location: Approximately 12.5 miles west of Melrose on the Canyon Creek Road, at the corner of the road overlooking the kilns; T2S lOW Sec 8; 7,200 ft elevation. a. West Transect Location: Moderate, south-facing slope. 162 degrees from the start pin to the southwest-most kiln; 227 degrees to the junction of the guard station road. Line bearing: 110 degrees Slope: 31 degrees Aspect: 205 degrees Instructions: Read transect west to east. b. East Transect Location: Moderate, south-facing slope. 178 degrees from the start pin to southwest-most kiln; 4 8 degrees to wooden platform. Line bearing: 96 degrees Slope: 30 degrees Aspect: 180 degrees Instructions: Read transect west to east. METHODS On June 15 (Lime Gulch) and 16 (Canyon Creek) , we established two permanent belt transects of 12 adjacent m^ plots at each site, following the methods outlined in Lesica (1987) . The start and end points of each transect were marked by a section of reinforcing bar driven into the ground and painted orange. Individual A. fecunda plants were mapped and recorded using the following system: S - Seedling (rosette less than 15 mm diameter) R - indicates the number of rosettes (> 15 mm diameter) per plant I - indicates the total number of inflorescences (stems) per plant F - indicates the total number of fruits produced by the plant Thus, a plant with two rosettes, three stems and a total of nine fruits would be recorded as R1-I3-F9. In cases where plants had not finished blooming, two flowers or flower buds were recorded as one fruit. Since a first year plant can bloom and set fruit (Lesica and Shelly, personal observation) , the above system describes size rather than age classes. At each site, we located 25 randomly-chosen plants outside of the transects, and picked one fruit from each. We dissected each fruit, and recorded the number of viable-appearing seeds in each. Many of the plants at Canyon Creek were still flowering when we read the transects; thus we recommend that this transect be read in late June or early July. RESULTS AND DISCUSSION A summary of the data collected in 1989 is presented in Table 1. All plants were mapped and scored to size class within each of the four transects. Fecundity was much greater in the Canyon Creek population than the Lime Gulch population. Also, the Canyon Creek population had a higher percentage of plants with more than one rosette. The Lime Gulch population is ca. 1,000 ft lower in elevation and in the rain shadow of the Pioneer Mountains. The differences in fecundity could be an artifact of sampling on consecutive days at sites which have very different microclimates, i.e., the phenology of the two populations may not be the same. The reason (s) for the difference in rosette number is unknown. Table 1. Population density and fecundity data for Arabis fecunda in long-term monitoring transects, Beaverhead National Forest, 1989. Canyon Creek Lime Gulch Density (plants/m^\ 15.8 15.4 # plants fruiting 95 6 % plants fruiting 25.1% 1.6% # fruits per 10.8 3.2 fruiting plant # fruits per 5.5 1.7 inflorescence % plants with more 20.3% 12.2% than one rosette % one-rosette plants 23.8% 0.9% with fruit % multi-rosette plants 29.9% 6.7% with fruit Seeds per fruit 34.2+10.5 31.1+5.1 LITERATURE CITED Drake, J. A. 1988. Biological invasions into nature reserves. Trends in Ecology and Evolution 3: 186-187. Lesica, P. 1985. Report on the conservation status of Arabis fecunda, a potential candidate species. Unpublished report to the U.S. Fish and Wildlife Service, Office of Endangered Species, Denver, CO. Lesica, P. 1987. A technique for monitoring nonrhizomatous, perennial plant species in permanent belt transects. Natural Areas Journal 7: 65-68. Massey, J. R. and P. D. Whitson. 1980. Species biology, the key to plant preservation. Rhodora 82: 97-103. Palmer, M. E. 1987, A critical look at rare plant monitoring in the United State. Biological Conservation 39: 113-127. Rollins, R. C. 1984. Studies in the Cruciferae of western North America II. Contr. Gray Herb. 214: 1-18. Schassberger, L. A. 1988. Update to the report on the conservation status of Arabis fecunda, a candidate threatened species. Unpublished report to the U.S. Fish and Wildlife Service, Office of Endangered Species, Denver, CO. 36 pp. Sutter, R. D. 1986. Monitoring rare plant species and natural areas - ensuring the protection of our investment. Natural Areas Journal 6: 3-5. ^ /^ (0,0 - /^rc^i re.^^U L/,^8i ' ^bilL^ fk-iTZil' L < /'^>7c ^^UXOI-L) Alcv,/K ^ /jr^ab.^ Pec^.u^t'/'io?^ MONTANA STATE This "cover" page added by the Internet Archive for formatting purposes