583.81 NllpLdd 1992 Achufff P. L Demographic monitoring of Pensteraon lemhiensist Dillon Resource Area* Bureau of Land :*c: MONTANA STATE LIBRARY S 583.8 ^ N i |pLdd 1 992 c i Achuft Demographic monitoring o( Penstemon (emh 0864 00083201 DEMOGRAPHIC MONITORING OF PENSTEMON LEMHIENSIS DILLON RESOURCE AREA BUREAU OF LAND MANAGEMENT ESTABLISHMENT AND PROGRESS REPORT by Peter L. Achuff Montana Natural Heritage Program 1515 East Sixth Avenue Helena, Montana 59620 STATE DOCUfilFMTS COLLECTION APR 1 ^ 1993 MONTANA STATE LIBRARY 1515 E. 6th AVE. HELENA, MONTANA 59G20 February 1992 TABLE OF CONTENTS I . INTRODUCTION 1 II . STUDY SITES 1 A. BADGER PASS MICROWAVE EXCLOSURE MARKED PLANTS 1 B. BADGER PASS MICROWAVE EXCLOSURE MONITORING TRANSECTS 4 C. HORSE PRAIRIE MONITORING TRANSECT 4 III . MONITORING METHODS 4 iV. RESULTS AND DISCUSSION 5 V . LITERATURE CITED 6 APPENDIX: DEMOGRAPHIC MONITORING DATA 7 INTRODUCTION Penstemon lemhiensis is currently in Category 2 (some evidence of vulnerability but not enough data to support listing at this time) of the U.S. Fish and Wildlife Service Notice of Review (U.S. Department of the Interior 1990). In an effort to collect the data needed to support or reject listing, populations of this species are being monitored in southwestern Montana. Populations on the Beaverhead National Forest have been monitored since 1989 (Achuff and Shelly 1991, Shelly 1990) . The species also occurs on BLM land and, in 1990, plants within a BLM exclosure at the Badger Pass microwave site were marked and described. In 1991, three demographic monitoring transects were established in the exclosure and an additional transect was established near the Horse Prairie, also on BLM land. Observations since 1986 of Penstemon lemhiensis population numbers at Badger Pass and other sites in southwestern Montana documented marked changes in population size, both increases and decreases (Achuff and Shelly 1991) . Such changes may make a species more prone to local extirpation. Thus, there is a need to better understand the demographic dynamics of local populations (survivorship and reproduction) so that an assessment of vulnerability can be made. An increased understanding of the biology of this species is also important to developing a realistic species conservation strategy (Massey and Whitson 1980) . II. STUDY SITES A. BADGER PASS MICROWAVE EXCLOSURE MARKED PLANTS The Badger Pass microwave site is located about 20 miles west of Dillon on Highway 278. An access road leads south from the top of the pass to the microwave site and the exclosure is immediately north of the tower. The marked plants within the exclosure are in three groups, each referenced to a marked fencepost of the perimeter fence. The plants are marked by metal pins in the ground which are marked with a metal tag. Some of the marked plants also occur in the three monitoring transects that were established in 1991. Group 1 (RPl) : RPl (Reference Point 1) is the fence post in the northernmost corner of the exclosure (Fig. 1) . The plants are located as follows: N RPl RP4 RP3 Figure 1. Exclosure at Badger Pass microwave site, Headinq Distance From To 231° 0. 50 m RPl plant 1 126° 3.75 m plant 1 plant 2 110° 3 . 60 m plant 2 plant 3 140° 1,75 m plant 3 plant 4 222° 4.95 m plant 4 plant 5 112° 4.30 m plant 5 plant 6 Group 2 (RP2): RP2 (Reference Point 2) is a corner post at a jog in the fence in the central northwest part of the exclosure (Fig. 1). The plants are located as follows : Heading Distance From To 112° 4.75 m RP2 plant 7 157° 23.15 m plant 7 plant 8 261° 13. 10 m plant 8 plant 9 260° 10.40 m plant 9 plant 10 301° 0.50 m plant 10 plant 11 195° 0.40 m plant 11 plant 12 318° 0.40 m plant 12 plant 13 83° 0.10 m plant 13 plant 14 27° 0.50 m plant 14 plant 15 222° 1.20 m plant 15 plant 16 90° 0.25 m plant 16 plant 17 132° 1.15 m plant 17 plant 18 132° 0.50 m plant 18 plant 19 253° 7.35 m plant 19 plant 22 nd 0.30 m plant 22 plant 23 nd 0.15 m plant 23 plant 24 nd 0.40 m plant 24 plant 26 nd 0.40 m plant 26 plant 27 nd 0.70 m plant 27 plant 29 148° 0.82 m plant 29 plant 30 165° 17.70 m plant 8 plant 31 7 0° 9.00 m plant 31 plant 32 Group 3 (RP3) : RP3 (Reference Point 3) is the fence post in the corner of the exclosure closest to the microwave tower (Fig. 1) . The plants are located as follows : Heading Distance From To 356° 12.40 m RP3 plant 33 55° 0.15 m plant 33 plant 34 157° 0.40 m plant 34 plant 35 174° 7.20 m plant 35 plant 36 228° 0.60 m plant 36 plant 37 nd 0.20 m plant 37 plant 38 nd 0.45 m plant 38 plant 39 60° 40.60 m plant 39 plant 40 1.25 m rebar plant 41 1.35 m rebar plant 42 1.34 m rebar plant 43 1.00 m plant 43 plant 44 190° 190° 190° 180° B. BADGER PASS MICROWAVE EXCLOSURE MONITORING TRANSECTS 1. Transect 1: The starting pin for transect 1 is located 3.58 m from RP3 (Fig. 1) on an azimuth of 10°. The transect runs for 10 m at 10° with the 1 m^ plots lying along the west side of the baseline. An additional 1 m^ plot lies on the east side of the baseline between meters 1 and 2. 2. Transect 2: The starting pin for transect 2 is 13.8 m at 160° from the omnidata pod cover (Fig. 1) and is at the south end of the transect. The transect runs at 340° for 5 m. The 1 m^ plots are along the east side of the baseline. 3. Transect 3: The starting pin for transect 3 is 2.8 m north of RP4 , a painted fence post along the southwestern perimeter fence (Fig. 1) and is at the south end of the transect. The transect runs for 5 m at 350° along the edge of the trees parallel to the fence, C. HORSE PRAIRIE MONITORING TRANSECT The Horse Prairie transect is located at the site of the Montana Natural Heritage Program element occurrence 027 for Penstemon lemhiensis. The site is about h mile southeast of the Horse Prairie Guard Station. The transect is located on the north side of the road between the second and third water bars as the road goes up the hill. The transect runs parallel to the road in a generally westerly direction and is 5 m long. The 1 m^ plots are north (upslope) of the base line. III. MONITORING METHODS The transects were established on 1 August 1991 following the methods of Lesica (1987). Individual plants were mapped on diagrams of each 1 m^ plot and characterized by life history feature as: S = seedling (cotyledons evident or rosette <15 mm in diameter) R = rosettes (basal tufts of leaves on mature plants) I = inflorescences (flowering stems) F = fruits A = aborted flowers (no fruit formation apparent) The total number per plant of each life history feature was also recorded, except for seedlings. Thus, a plant with five rosettes, two inflorescences, 12 fruits, and 25 aborted flowers was recorded as R5l2F,2^25' ■^^ some other Penstemon lemhiensis monitoring sites, seed capsules have been collected randomly and examined for the number of viable- appearing seeds (Achuff and Shelly 1991, Shelly 1990) . However, there were so few capsules in 1991 at the monitoring sites that none were collected. IV. RESULTS AND DISCUSSION The Penstemon lemhiensis population within the Badger Pass exclosure has been followed for several years. In 1986, 75 plants were reported within the exclosure and in 1990, 38 plants were seen within the exclosure. In 1991, 51 plants were recorded within the exclosure as marked plants or within the transects; no effort was made to count all plants within the exclosure. Thus, the observations have not been made in a sufficiently rigorous way, either in terms of plant numbers or demographic category, that conclusions can be drawn regarding population trend. Among the 34 plants marked in 1990 and relocated in 1991, the was no consistent trend. Of these, four died, about half remained unchanged, and the remainder were evenly divided between those that increased and those that decreased in size or vigor. In summary, the present data are not sufficient to draw any conclusions but observing the individual plants over several years and the possible recruitment of new plants in the transects will provide a valid basis for assessing the demographic and life history status of this species. V. LITERATURE CITED Achuff, P.L. and J.S. Shelly. 1991. Demographic monitoring of Penstemon lemhiensis, Beaverhead National Forest, 1990 progress report. Montana Natural Heritage Program, Helena. 34 pp. Massey, J.R. and P.D. Whitson. 1980. Species biology, the key to plant preservation. Rhodora 82: 97-103. Shelly, J.S. 1990. Status review and establishment of demographic monitoring studies: Penstemon lemhiensis . Montana Natural Heritage Program report to Be< verhead and Bitterroot national forests, Montana. 61 pp. U.S. Department of the Interior. 1990. Endangered and threatened wildlife and plants; review of taxa for listing as endangered and threatened species; notice of review. Federal Register 50 CFR Part 17: 6184-6229. APPENDIX: DEMOGRAPHIC MONITORING DATA These data show the performance of individual Penstemon lemhiensis plants in permanent monitoring plots in 1991 and, for some plants, in 1990. The following codes are used: A = aborted flowers (no fruit formation apparent) B = browsed flowering stem D = dead F = fruits I = inflorescences (flowering stems) P = predated R = rosettes (basal tufts of leaves on mature plants) S = seedling (cotyledons evident or rosette <15 mm in diameter) The codes form a formula describing the state of the plant. For example, a plant with five rosettes, two inflorescences, 12 fruits, and 25 aborted flowers was recorded as R5l2F^2^25 BADGER PASS MICROWAVE EXCLOSURE MARKED PLANTS - RPl Plant 1990 1991 1 R4 D 2 Rl Rl 3 R4I1F14A17 R3I1F6A6 4 R3 R4 5 R12I1F24A10 R11I3F13A16P1 6 R2 RlPl BADGER PASS MICROWAVE EXCLOSURE MARKED PLANTS - RP2 Plant 1990 1991 7 R4I1F15A19 R5I3F31A75 8 Rl D 9 R6I4F4A109+ R7 10 R8 R7I2F12A64 11 R6 R4 12 R5 R4I1F5A34 13 R2I1F7A17 R4 14 Rl R3 14A — Rl BADGER PASS MICROWAVE EXCLOSURE MARKED PLANTS - RP2 (cont.) Plant 1990 1991 15 R4B1F1 R3I3F23A84 16 R5 R4 17 R2I1F13A19 R5I1F11A41 18 R4I1F12A21 R13I4F48A151 19 R4B1 R15 22 R8I1F6A10B1 R8I2F1A4B2 23 R5I1F1A3B1 R5I3F17A45 24 R7I2F23A31B1 R12I1F2A3B1 26 Rl R3 27 R6 R8I1B1 29 Rl R4I1F6A27 30 — R7I1F15A38 31 R5 R3I2F8A61 32 R3I1F11A24 R3 BADGER PASS MICROWAVE EXCLOSURE MARKED PLANTS - RP3 Plant 1990 1991 33 R4 Rl 34 R3B1 Rl 35 R14I2F36A35 R4I2B2 36 R3I1F8A27 R3 37 R3I1F8A32 R3 38 R2I1F8A27 R3 39 R2 Rl 40 — R2I1F4A17 41 — R1I1F6A16 42 -- R4I1F8A14 43 -- R3 44 -- R13I1F14A27 BADGER PASS MICROWAVE TRANSECT 1 The number in parentheses is the tag number for numbered plants that occur within a transect. Plot Plant 1990 1 no plants 2 a R2 b (37) R3 C (38) R3 3-8 no plants BADGER PASS MICROWAVE TRANSECT 1 (cont.) Plot PI ant 1990 9 a (35) R4I2B2 b (34) Rl c (33) Rl 10 no plants 11 a (36) R3 b (39) Rl c (40) R2I1F4A17 BADGER PASS MICROWAVE TRANSECT 2 The number in parentheses is the tag number for numbered plants that occur within a transect. Plot PI ant 1990 1 a R3I3F14A35 2-3 no plants 4 a R4I3F14A44 b R4I1F4A12 c R2 d R3I2F15A4 5 a Rl (dead?) b R1I1F5A23 c Rl d R5I1F8A23 6-8 no plants 9 a (41) R1I1F6A16 b (42) R4I1F8A14 c (43) R3 10 a (44) R13I1F14A27 BADGER PASS MICROWAVE TRANSECT 3 The number in parentheses is the tag number for numbered plants that occur within a transect. Plot Plant 1990 1 no plants 10 BADGER PASS MICROWAVE TRANSECT Plot Plant 1990 2 a (30) R7I1F15A38 b (29) R4I1F6A27 3 a Rl b (24) R12I1F2A3B1 c (27) R8I1B1 d (23) R5I3F17A45 e (22) R8I2F1A4B2 4 a Rl 4 b (26) R3 c Rl 5 no plants 3 (cont.) HORSE PRAIRIE MONITORING TRANSECT Plot Plant 1990 1 a R2 b Rl c Rl d R2 e R2 f R2 g R2 h Rl i R2 J Rl k Rl 2 a Rl b R2 c R14 d Rl e Rl f R2 g R2 h R3 i S 3 a R8I2B2 b Rl c R12I5F63A55B2 d R10I4F208A65P1 e R2 f Rl 11 HORSE PRAIRIE MONITORING TRANSECT (cont.) Plot Plant 1990 g Rl h R3 i R2 J R5 k Rl 1 Rl m Rl n Rl o R3 P R2 4 a R11I1F92A24 b Rl c S 5 no plants i