s 583.57 Nllhasr 1988 MONTANA STATE LIBRARY S 583.57 N1 1hasr 1988 c.1 Shelly Status review of Howellla aquatilit, U.S cljjJl 3 0864 00082569 8 STATUS REVIEW OF Howell ia aouatilis U.S. FOREST SERVICE - REGION 1 FLATHEAD NATIONAL FOREST MONTANA f/CMTAMA STATE' UPRA^Y 1 ! -;i^ i'\ cih AVE, HITLE.viA, MOrrAMA L9C20 Prepared by: J. Stephen Shelly, Botanist Montana Natural Heritage Program State Library Building 1515 E. 6th Avenue Helena, MT 59620 Order No. 40-0385-8-0190 19 January 1988 & i&E&rf £*£*«/ :.?.' -^ * ; » T . TABLE OF CONTENTS I- SPECIES INFORMATION Page A. Classification 1 B. Present legal or other formal status 1 C. Description S D. Geographical distribution 4 E. Habitat 17 F. Population demography and biology 21 G. Population ecology 3S H- Land ownership (Montana) 33 II. ASSESSMENT AND MANAGEMENT RECOMMENDATIONS A. Threats to currently known populations (Montana) 34 B. Management practices and response 36 C. Recommendations for maintaining viable populations 36 D. Recommendations for further assessment 38 E. Summary 38 III. LITERATURE CITED 39 IV. ELEMENT OCCURRENCE PRINT-OUTS AND MAPS 41 V. PHOTOGRAPHS 113 I. SPECIES INFORMATION A. CLASSIFICATION 1. SCIENTIFIC NAME: Howellia aouatilis A. Gray. 2. COMMON NAME: Water howellia. 3. FAMILY: Campanulaceae (Harebell Family). *f. GENUS: Howel 1 ia is a monotypic genus, represented by H. aquati 1 is . The taxon was first discovered in 1879 by Thomas and Joseph Howell, near Portland $ Oregon. These original specimens were subsequently determined to be a new genus and species by Asa Gray* who described it in the scientific literature that year (Gray* 1879). The genus which seems most closely related to Howel 1 ia is Leqenere . This genus is also monotypic, consisting only of the species L. 1 imosa, and occurs in dried beds of vernal pools in the Central Valley of California (Munz, 1959). Within the Campanulaceae, Howel 1 ia is placed in the subfamily Lobel ioideae, distinguished from the subfamily Campanuloideae in having irregular (asymmetric) corollas* as opposed to the regular (symmetric) corollas of the latter. B. PRESENT LEGAL OR OTHER FORMAL STATUS 1. FEDERAL STATUS a. U.S. FISH AND WILDLIFE SERVICE: Howellia aquatil is is currently included in Category 2 of the U.S. Fish and Wildlife Service Notice of Review (Federal Register, 9/27/85) , under consideration for federal listing as an endangered species. Category 2 taxa are those "...for which information now in possession of the Service indicates that proposing to list them as endangered or threatened species is possibly appropriate, but for which substantial data on biological vulnerability and threat (s) are not currently known or on file to support the immediate preparation of rules" (= federal candidate taxa) . b. U.S. FOREST SERVICE: Howellia aquatilis is currently included on the list of proposed sensitive species for Region 1 (Northern Region) of the U.S. Forest Service (Pierce et. al. , 1987 draft). Agency objectives and policy in the 1984 Forest Service Manual provide for the management and protection of sensitive species (Sections 2670.22, 2670.32). Under these guidelines, the U.S. Forest Service is to M (a)void or minimize impacts to species whose viability has been identified as a concern" (2670.32.3), and is to "(e)stablish objectives for Federal candidate species, in cooperation with the FWS...and the states" (2670.32.5). STATE: Howel 1 ia aquati 1 is has been listed as "recommended endangered" by the Montana Rare Plant Project (Lesica et ad. , 1984). This category includes "(a)ny species that is in danger of extinction throughout all or a significant portion of its range in Montana." Howel 1 ia aquati 1 is is currently listed by the Montana Natural Heritage Program (Shelly, 1988) as "endangered throughout range" (6 - 20 occurrences; global rank = 62). In Montana, it is listed as "critically endangered", owing to factors making it especially vulnerable to extirpation from the state (state rank » SI), None of these federal or state ranks currently provide any direct legal protection for H. aquati 1 is . C. DESCRIPTION GENERAL NONTECHNICAL DESCRIPTION: Howel lia aquati 1 is is a strictly aquatic species, which occurs as a mostly submerged plant rooted in the bottom sediments of the ponds and sloughs to which it is adapted. It is an annual, completing its entire life cycle in one growing season, and disappearing completely upon desiccation of its habitat at the end of the summer. The stems are branched several inches from the base, and each branch then extends to the surface of the water. The numerous leaves are an inch or two long, and very narrow. Howel 1 ia aquati 1 is produces two types of flowers. Along the stem beneath the water surface, small flowers form which do not develop a conspicuous corolla (floral tube). In addition, as the branches reach the surface, more conspicuous flowers develop above the water. These emergent flowers are white, have five lobes on one side of the corolla, and are about '4 inch across. Both types of flowers give rise to thin-walled fruits which are an inch or more long* and which contain one to five or so large, shiny brown seeds which can be about v 4 inch long. In Montana, the emergent flowers are in bloom from late June to August. The actual duration may be longer in certain cases, depending on the rate of drying of the habitat. See Section V, pp. 113-120, for color photos of the plants and habitat. 2. TECHNICAL DESCRIPTION: Flaccid annual, aquatic herb f mostly submergent, often with emergent branches; plants naked below, branched above; whole plant glabrous, green, about 10-60 cm. (4-24 in.) tally occasionally taller; leaves numerous, alternate, or some of them subopposite or whorled in threes, linear or lineai — filiform, entire or nearly so, 1-5 cm. (0.4-2 in.) long, up to 1.5 mm. (0.06 in.) wide; flowers white, mostly 3-10, axillary, often scattered, pedicellate or subsessile, both petal if erous (when emergent) or much reduced and inconspicuous (when submerged), the fully-developed corollas about 2-2.7 mm (0.08- 0.11 in.) long, irregular, with the tubes deeply cleft dorsally, and five-lobed; filaments and anthers connate, two of the anthers shorter than the others; calyx lobes 1.5-7 mm. (0.06-0.28 in.) long; stout pedicels 1-4 (8) mm. (0.04-0.16 (0.3) in.) long, merging gradually with the base of the capsule; ovary unilocular, with parietal placentation; stigma 2-lobed; fruit 5-13 mm. (0.2- 0.5 in.) long, 1-2 mm. (0.04-0.08 in.) thick, irregularly dehiscent by the rupture of the very thin lateral walls; seeds large, 2-4 mm. (0.08- 0.16 in.) long, 5 or fewer, shiny brown (adapted from Hitchcock e£ al_. , 1959; Dorn, 1984). 3. LOCAL FIELD CHARACTERS: Howell ia aouatilis is the only member of the Campanulaceae in Montana which is strictly aquatic. Powninaia laeta can occur in wet places in meadows or on the edges of ponds, but is distinguishable by its light blue or purplish flowers marked with white or yellow; it was not observed in the Swan Valley during field surveys. Heterocodon rariflorum , a species of moist areas in Lake and Ravalli Counties, has regular, blue flowers. The annual habit, distinctive habitat, and irregular white flowers of H. aquati 1 is thus serve to distinguish it from all other members of the family in northwestern Montana. D. GEOGRAPHICAL DISTRIBUTION 1. RANGE: Howell ia aguati lis is currently known from a total of ten sites, in Washington (Clark and Spokane Counties; J. Gamon, WA Natural Heritage Program, pers. comm. ) , and Montana (Swan Valley* eastern Lake and northeastern Missoula Counties). It is historically known from one collection in California (Mendocino County; Smith and York, 198*f), three locations in northwestern Oregon (S. Yamamoto, OR Natural Heritage Program, pers. comm.), and two collections (one possibly misidentif ied) in northern Idaho (S. Caicco, ID Natural Heritage Program, pers. comm.). In Montana, it has been located on the Flathead National Forest, as well as on private lands. 2. CURRENT SITES (MONTANA): Howell ia aouatilis was first discovered in Montana, near Lindbergh Lake in Missoula County, in 1978 (McCune, 1982). Since that time, it has been documented from six additional sites, all in Lake (4) and Missoula (2) Counties. The seven known locations are all in the Swan Valley, from near Lindbergh Lake to Swan Lake. At these seven sites, it is found in one to twelve or more adjacent ponds or oxbow sloughs; a total of 52 populations have been located. The legal descriptions, latitude, and longitude, elevations, USGS topographic quad names, and locations of the populations at each site are provided in Table l; Table IA (pp. 5-11) lists those populations which occur wholly or partially on U.S. Forest Service lands, and Table IB (pp. 12-15) lists those sites on lands of other ownership. The distribution in Montana is indicated in Figure 1 (p. 16); the exact locations are indicated on the maps provided in Section IV, pp. 94-101. Throughout this report, the three- digit occurrence numbers are indicated in parentheses after the site names, and correspond to the numbers on the computer print-outs. 3. HISTORICAL SITES (MONTANA): All populations of H. aguati 1 is in Montana have been recently verified (1984-1987). There are no known historical records in the state. 4. UNVERIFIED REPORTS (MONTANA): None. 5. AREAS SURVEYED BUT SPECIES NOT LOCATED: Prior to 1987, 176 ponds or other wetland habitats had been surveyed for H. aguati 1 is ; of these, 16 support populations, and 160 apparently do not. In 1987, 172 additional wetland locations were surveyed; TABLE 1A. J-bwel 1 ia aquatilis locations wholly or partially occurring on U.S. Forest Service lands, Missoula and Lake Counties, Montana. Occurrences are clustered under the site naae, and are then listed in numerical order. CONDON CREEK Occurrence nuiber: 006 COUNTY: MISSOULA Township I Range: 021N016W Section: 18 Subsection/additional sections: NE4NW4SW4 Latitude: 473442 Longitude: 1134217 Elevation: 3740 US6S Quad: CONDON Location: SWAN VALLEY, WEST BASE OF SWAN RANGE UPLIFT, 3.5 AIR MILES NORTH OF CONDON, 2.1 AIR MILES EAST OF ST. HWY. 83, 0.1 AIR MILES SOUTH OF CONDON CREEK. Occurrence nutber: 020 COUNTY: MISSOULA Township I Range: 021N016W Section: 18 Subsection/additional sections: SW4NE4SW4 Latitude: 473433 Longitude: 1134212 Elevation: 3740 US6S Quad: CONDON Location: SWAN VALLEY, 3.3 AIR MILES NORTH OF CONDON, 2.13 AIR MILES EAST OF ST. HWY 83, 0.25 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 021 COUNTY: MISSOULA Township I Range: 021N016W Section: 18 Subsection/additional sections: SU4NE4SW4 Latitude: 473432 Longitude: 1134216 Elevation: 3740 US6S Quad: CONDON Location: SWAN VALLEY, 3.3 AIR MILES NORTH OF CONDON, 2.08 AIR MILES EAST OF ST. HWY 83, 0.28 AIR MILES SOUTH OF CONDON CREEK. Occurrence nutber: 022 COUNTY: MISSOULA Township & Range: 021N016W Section: 18 Subsection/additional sections: SW4NE4SW4 Latitude: 473431 Longitude: 1134207 Elevation: 3750 USGS Quad: CONDON Location: SWAN VALLEY, 3.28 AIR MILES NORTH OF CONDON, 2.18 AIR MILES EAST OF ST. HWY 83, 0.27 AIR MILES SOUTH OF CONDON CREEK. Occurrence nutber: 023 COUNTY: MISSOULA Township & Range: 021N016W Section: 18 Subsection/additional sections: NW4SE4SW4 Latitude: 473427 Longitude: 1134214 Elevation: 3740 US6S Quad: CONDON Location: SWAN VALLEY, 3.2 AIR MILES NORTH OF CONDON, 2.10 AIR MILES EAST OF ST. HWY 83, 0.35 AIR MILES SOUTH OF CONDON CREEK. TABLE 1A. (cont.). CQNDQN CREEK tcont.) Occurrence number: 024 COUNTY: MISSOULA Township & Range: 021N016W Section: 18 Subsection/additional sections: SW4SE4SW4 Latitude: 473422 Longitude: 1134212 Elevation: 3740 USGS Quad: CONDON Location: SWAN VALLEY, 3.09 AIR MILES NORTH OF CONDON, 2.10 AIR MILES EAST OF ST. HWY 83, 0.47 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 025 COUNTY: MISSOULA Township & Range: 021N016W Section: 18 Subsection/additional sections: S2SE4SW4 Latitude: 473421 Longitude: 1134206 Elevation: 3750 US6S Quad: CONDON Location: SWAN VALLEY, 3.08 AIR MILES NORTH OF CONDON, 2.18 AIR MILES EAST OF ST. HWY 83, 0.45 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 026 COUNTY: MISSOULA Township & Range: 021N016W Section: 18 Subsection/additional sections: SE4NW4SW4 Latitude: 473432 Longitude: 1134225 Elevation: 3710 US6S Quad: CONDON Location: SWAN VALLEY, 3.29 AIR MILES NORTH OF CONDON, 1.97 AIR MILES EAST OF ST. HWY 83, 0.28 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 027 COUNTY: MISSOULA Township & Range: 021N016W Section: 18 Subsection/additional sections: NW4SW4SW4 Latitude: 473426 Longitude: 1134233 Elevation: 3690 USGS Quad: CONDON Location: SWAN VALLEY, 3.18 AIR MILES NORTH OF CONDON, 1.84 AIR MILES EAST OF ST. HWY 83, 0.40 AIR MILES SOUTH OF CONDON CREEK. DOB CREEK Occurrence nuiber: 018 COUNTY: LAKE Township & Range: 021N017W Section: 02 Subsection/additional sections: SE4NW4SE4 Latitude: 473618 Longitude: 1134412 Elevation: 3660 USGS Quad: CONDON Location: SWAN VALLEY, EAST SIDE OF FLATHEAD N.F. RD. 1899 NEAR JUNC- TION WITH RD. 1124, 0.35 AIR MILES NORTH OF LAKE-MISSOULA COUNTY LINE, CA. 5.5 AIR MILES NNW OF CONDON. TABLE 1A. (cont.). DQ6 CREEK (cont.) Occurrence nuiber: 019 COUNTY: LAKE Township l Range: 021N017W Section: G2 Subsection/additional sections: S2NE4SW4 Latitude: 473618 Longitude: 1134441 Elevation: 3580 US6S Quad: CONDON Location: SWAN VALLEY, 0.33 AIR MILES WEST OF JUNCTION OF FLATHEAD NF RDS. 899 AND 124, 0.33 AIR MILES NORTH OF LAKE-MISSOULA CO. LINE, CA. 5.5 AIR MILES NNU OF CONDON. LINDBER6H LAKE Occurrence number: 001 COUNTY: MISSOULA Township I Range: 019N017W Section: IE Subsection/additional sections: NE4SE4NW4 Latitude: 472521 Longitude: 1134231 Elevation: 4230 US6S Quad: CY6NET LAKE Location: SWAN VALLEY, 0.68 AIR MILES NNE. FROM THE FIRST FORK ON LINDBERGH LAKE ROAD, CA. 2.5 MILES WEST FROM ST. HWY. 83. Occurrence nuiber: 036 COUNTY: MISSOULA Township I Range: 019N016W Section: 07 Subsection/additional sections: SW4SW4NW4;T19NR17W:4 Latitude: 472514 Longitude: 1134148 Elevation: 4190 US6S Quad: CY6NET LAKE Location: ALSO 12SE4SE4NE4; SWAN VALLEY, SOUTH SIDE OF LINDBER6H LAKE RD.i CA. 1.87 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 043 COUNTY: MISSOULA Township I Range: 019N017W Section: 12 Subsection/additional sections: SW4NW4NW4 Latitude: 472526 Longitude: 1134303 Elevation: 4280 USGS Quad: CY6NET LAKE Location: SWAN VALLEY, 0.76 AIR MILES NORTH OF LINDBERGH LAKE RD., 2.68 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 044 COUNTY: MISSOULA Township I Range: 019N017W Section: 12 Subsection/additional sections: S2SE4NE4, N2NE4SE4 Latitude: 472508 Longitude: 1134156 Elevation: 4215 US6S Quad: CYGNET LAKE Location: SWAN VALLEY, SOUTHEAST OF LINDBERGH LAKE RD., 2.0 AIR MILES WEST OF ST. HWY 83. 8 TABLE 1A. (cont.). LINDBERGH LAKE tcont.) Occurrence nuaber: 045 COUNTY: MISSOULA Township & Range: 019N016W Section: 18 Subsection/additional sections: SE4SW4SE4 Latitude: 472354 Longitude: 1134058 Elevation: 4250 US6S Quad: CY6NET LAKE Location: SWAN VALLEY, 1.83 AIR MILES ESE OF NORTH END OF LINDBERGH LAKE, 1.08 AIR MILES SOUTH OF SWAN RIVER, CA. 2.0 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 046 COUNTY: MISSOULA Township I Range: 019N016W Section: 18 Subsection/additional sections: SW4NW4NW4 Latitude: 472434 Longitude: 1134141 Elevation: 4230 US6S Quad: CY6NET LAKE Location: SWAN VALLEY, 0.58 AIR MILES SOUTH OF SWAN RIVER, 2.13 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 047 COUNTY: MISSOULA Township I Range: 019N01&W Section: 18 Subsection/additional sections: SW4NE4NW4 Latitude: 472433 Longitude: 1134127 Elevation: 4215 US6S Quad: CY6NET LAKE Location: SWAN VALLEY, 0.5 AIR MILES SOUTH OF SWAN RIVER, 1.95 AIR MILES WEST OF ST. HWY 83. Occurrence nutber: 048 COUNTY: MISSOULA Township I Range: 019N016W Section: 18 Subsection/additional sections: SW4NE4NW4 Latitude: 472432 Longitude: 1134122 Elevation: 4215 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 0.5 AIR MILES SOUTH OF SWAN RIVER, 1.89 AIR MILES WEST OF ST. HWY 83. Occurrence nutber: 051 COUNTY: MISSOULA Township I Range: 019N017W Section: 24 Subsection/additional sections: NE4SE4NW4 Latitude: 472335 Longitude: 1134229 Elevation: 4425 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 0.91 AIR MILES EAST OF EAST SHORE OF LINDBERGH LAKE, 0.8 AIR MILES SSE OF SOUTH SHORE OF CYGNET LAKE, CA. 3.3 AIR MILES WEST OF ST. HWY 83. TABLE 1A. (cont.) LOST CREEK-CILLY CREEK PONDS Occurrence nuiber: 008 COUNTY: LAKE Township I Range: 024N017W Section: 06 Subsection/additional sections: NW4SW4SE4 Latitude: 475148 Longitude: 1134933 Elevation: 3190 USeS Quad: CILLY CREEK Location: SWAN VALLEY, CA. 4.5 AIR MILES SSE. OF SHAN LAKE (TOUN); 0.3 AIR MILES EAST OF ST. HWY. 83; 0.6B AIR MILES SSW. OF CONFLUENCE OF NORTH AND SOUTH FORKS LOST CREEK. Occurrence nuiber: 009 COUNTY: LAKE Township I Range: 024N017W Section: 07 Subsection/additional sections: NE4NE4NE4 Latitude: 475137 Longitude: 1134907 Elevation: 3250 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.6 AIR MILES EAST OF ST. HWY. 83, 0.6 AIR MILES SOUTH OF SOUTH FORK LOST CREEK, CA. 5.0 AIR MILES SSE OF SWAN LAKE (TOWN). Occurrence nuiber: 010 COUNTY: LAKE Township I Range: 024N017W Section: 05 Subsection/additional sections: NW4SW4SW4 Latitude: 475150 Longitude: 1134857 Elevation: 3230 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.75 AIR MILES EAST OF ST. HWY 83, 0.3 AIR MILES SOUTH OF SOUTH FORK LOST CREEK, CA. 4.7 AIR MILES SSE OF SWAN LAKE (TOWN). Occurrence nuiber: Oil COUNTY: LAKE Township I Range: 024N017W Section: OB Subsection/additional sections: E2SE4NW4, NW4SW4NE4 Latitude: 475120 Longitude: 1134826 Elevation: 3290 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 1.05-1.2 AIR MILES EAST OF ST. HWY 83, 0.25 AIR MILES NNE OF CILLY CREEK, CA. 5.0 AIR MILES SSE OF SWAN LAKE (TOWN). Occurrence nuiber: 012 COUNTY: LAKE Township I Range: 024N017W Section: 08 Subsection/additional sections: NE4SW4NW4,SE4NW4NW4 Latitude: 475125 Longitude: 1134848 Elevation: 3235 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.83 AIR MILES EAST OF ST. HWY 83, 0.37 AIR MILES NORTH OF CILLY CREEK, CA. 5.0 AIR MILES SSE OF SWAN LAKE (TOWN). 10 TABLE 1A. (contJ LOST CREEK-CILLY CREEK PONDS (cont.) Occurrence nuiber: 013 COUNTY: LAKE Township & Range: 024N017W Section: 08 Subsection/additional sections: N2SW4NW4 Latitude: 475124 Longitude: 1134852 Elevation: 3240 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.79 AIR HILES EAST OF ST. HWY 83, 0.36 AIR MILES NORTH OF CILLY CREEK, CA. 5.0 AIR MILES SSE OF SHAN LAKE {TOUN). Occurrence nuiber: 014 COUNTY: LAKE Township I Range: 024N017W Section: 08 Subsection/additional sections: NW4SW4NW4 Latitude: 475124 Longitude: 1134857 Elevation: 3245 USGS Quad: CILLY CREEK Location: SWAN VALLEY, 0.72 AIR MILES EAST OF ST. HWY 83, 0.4 AIR MILES NORTH OF CILLY CREEK, CA. 5.0 AIR MILES SSE OF SWAN LAKE (TOWN). Occurrence nuiber: 015 COUNTY: LAKE Township & Range: 024N017W Section: 08 Subsection/additional sections: NW4SW4NW4 Latitude: 475121 Longitude: 1134856 Elevation: 3245 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.73 AIR HILES EAST OF ST. HWY 83, 0.32 AIR HILES NORTH OF CILLY CREEK, CA. 5.0 AIR HILES SSE OF SWAN LAKE (TOWN). Occurrence nuiber: 016 COUNTY: LAKE Township I Range: 024N017W Section: 06 Subsection/additional sections: NW4NW4SW4 Latitude: 475111 Longitude: 1134B57 Elevation: 3240 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.71 AIR HILES EAST OF ST. HWY 83, 0.17 AIR MILES NORTH OF CILLY CREEK, CA. 5.0 AIR MILES SSE OF SWAN LAKE (TOWN). Occurrence nuiber; 017 COUNTY: LAKE Township I Range: 024N017W Section: 08 Subsection/additional sections: NE4NW4SW4 Latitude: 475110 Longitude: 1134845 Elevation: 3230 US6S Quad: CILLY CREEK Location: SWAN VALLEY, 0.85 AIR HILES EAST OF ST. HWY 83, 0.1 AIR HILES NORTH OF CILLY CREEK, CA. 5.0 AIR HILES SSE OF SWAN LAKE (TOWN), 11 TABLE 1A. (cont.) SWAN RIVER OXBOW Occurrence nunber: 005 COUNTY: LAKE Township I Range: 025N018W Section: 35 Subsection/additional sections: NW4;34,NE4NE4;26,SW4 Latitude: 475327 Longitude: 1135117 Elevation: 3100 USES Quad: SWAN LAKE Location: CA. 3 MILES SOUTH OF THE VILLAGE OF SWAN LAKE ON ST. HWY. 83, 0.7 MILES WEST ON PORCUPINE CREEK ROAD; 0.2-0.7 AIR HI. N. OF PORCUPINE CREEK ROAD. SWAN RIVER WEST Occurrence nuaber: 007 COUNTY: LAKE Township I Range: 024N01BW Section: 14 Subsection/additional sections: SW4SE4SE4 Latitude: 474958 Longitude: 1135131 Elevation: 3190 USGS Quad: CILLY CREEK Location: WEST SIDE OF SWAN VALLEY, 1.4 AIR MILES WEST OF ST. HWY. 83; 0.57 AIR MILE WEST OF SWAN RIVER; CA. 6.5 AIR MILES SOUTH OF SWAN LAKE (TOWN). la TABLE IB. Howellia aquatilis locations on areas other than U.S. Forest Service lands, Missoula County, Montana. Occurrences are clustered under the site naie, and are then listed in numerical order. CDNDDN CREEK Occurrence nuiber: 028 COUNTY: MISSOULA Township & Range: 021N017W Section: 13 Subsection/additional sections: SE4SE4SE4 Latitude: 473422 Longitude: 1134240 Elevation: 3685 USES Quad: CONDON Location: SWAN VALLEY, 3.09 AIR MILES NORTH OF CONDON, 1.75 AIR MILES EAST OF ST. HWY 83, 0.48 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 029 COUNTY: MISSOULA Township I Range: 021N016W Section: 1? Subsection/additional sections: NW4NW4NW4 Latitude: 473415 Longitude: 1134228 Elevation: 3690 US6S Quad: CONDON Location: SWAN VALLEY, 2.97 AIR MILES NORTH OF CONDON, 1.88 AIR MILES EAST OF ST. HWY B3, 0.59 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 030 COUNTY: MISSOULA Township I Range: 021N016W Section: 19 Subsection/additional sections: NE4NE4NW4 Latitude: 473416 Longitude: 1134204 Elevation: 3740 US6S Quad: CONDON Location: SWAN VALLEY, 2.99 AIR MILES NORTH OF CONDON, 2.19 AIR MILES EAST OF ST. HWY 83, 0.55 AIR MILES SOUTH OF CONDON CREEK. Occurrence nuiber: 031 COUNTY: MISSOULA Township I Range: 021N017W Section: 13 Subsection/additional sections: E2NE4SW4,W2NW4SE4 Latitude: 473436 Longitude: 1134315 Elevation: 3620 US6S Quad: CONDON Location: SWAN VALLEY, 3.36 AIR MILES NORTH OF CONDON, 1.33 AIR MILES EAST OF ST. HWY B3, 0.32 AIR MILES SOUTH OF CONDON CREEK. KRAFT CREEK Occurrence nuiber: 052 COUNTY: MISSOULA Township & Range: 020N017W Section: 22 Subsection/additional sections: SE4 Latitude: 472829 Longitude: 1134432 Elevation: 4010 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, CA. 0.5 AIR MILES WNW OF NORTH END OF STONER LAKE, 0.35 AIR MILES EAST OF GLACIER CREEK, 3.15 AIR MILES WEST OF ST. HWY 83. 13 TABLE IB. (cont.). LINDBERGH LAKE Occurrence nuaber: 002 COUNTY: MISSOULA Township & Range: 019N017W Section: 01 Subsection/additional sections: E2NE4SW4 Latitude: 472556 Longitude: 1134232 Elevation: 4175 US6S Quad: CYGNET LAKE Location: SWAN VALLEY, 1.32 AIR MILES NORTH OF THE FIRST FORK ON LINDBERGH LAKE RD., CA. 2.5 MI. WEST OF ST. HHY. 83. Occurrence nuiber: 003 COUNTY: MISSOULA Township I Range: 019N016W Section: 07 Subsection/additional sections: E2SW4NW4,W2SE4NW4 Latitude: 472516 Longitude: 1134128' Elevation: 4150 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 0.1 AIR MILES SOUTH OF LINDBERGH LAKE RD., CA. 1.5 MILES WEST OF ST. HHY. 83. Occurrence nuiber: 004 COUNTY: MISSOULA Township I Range: 019N016W Section: 07 Subsection/additional sections: SE4NE4 Latitude: 472515 Longitude: 1134041 Elevation: 4070 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, CA. 50 FT. SOUTHWEST OF LINDBERGH LAKE RD., CA. 1 MILE WEST OF ST. HWY. 83. Occurrence nuiber: 032 COUNTY: MISSOULA Township I Range: 019N016W Section: 07 Subsection/additional sections: SE4SW4NW4 Latitude: 472511 Longitude: 1134134 Elevation: 4165 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 0.16 AIR MILES SOUTH OF LINDBERGH LAKE RD., CA. 1.75 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 033 COUNTY: MISSOULA Township & Range: 019N016W Section: 07 Subsection/additional sections: N2SE4NW4 Latitude: 472520 Longitude: 1134119 Elevation: 4130 US6S Quad: CYGNET LAKE Location: SWAN VALLEY, 0.05 AIR MILES SOUTH OF LINDBERGH LAKE RD., CA. 1.5 AIR MILES WEST OF ST. HWY 83. 1<+ TABLE IB. (cont.). LINDBERGH LAKE (cont.) Occurrence nuiber: 034 COUNTY: MISSOULA Township & Range: 019N016W Section: 07 Subsection/additional sections: NE4NE45W4 Latitude: 472507 Longitude: 1134116 Elevation: 4145 USSS Quad: CYGNET LAKE Location: SHAN VALLEY, 0.3 AIR MILES SOUTH OF LINDBERGH LAKE RD., CA. 1.5 AIR MILES WEST OF ST. HUY 83. Occurrence nutber: 035 COUNTY: MISSOULA Township & Range: 019N016W Section: 07 Subsection/additional sections: E2NE4SW4 Latitude: 472502 Longitude: 1134114 Elevation: 4150 US6S Quad: CYGNET LAKE Location: SWAN VALLEY, 0.38 AIR MILES SOUTH OF LINDBERGH LAKE RD., CA. 1.5 AIR MILES WEST OF ST. HWY 83. Occurrence nutber: 037 COUNTY: MISSOULA Township t Range: 019N017W Section: 01 Subsection/additional sections: SW4NE4SE4 Latitude: 472551 Longitude: 1134203 Elevation: 4170 US6S Quad: CYGNET LAKE Location: SWAN VALLEY, 0.93 AIR MILES NORTH OF LINDBERGH LAKE RD., CA. 1.69 AIR MILES WEST OF ST. HWY 83. Occurrence nutber: 038 COUNTY: MISSOULA Township I Range: 019N017W Section: 01 Subsection/additional sections: E2SW4NE4 Latitude: 472608 Longitude: 1134215 Elevation: 4130 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 1.33 AIR MILES NORTH OF LINDBERGH LAKE RD., CA. 1.62 AIR MILES WEST OF ST. HWY 83. Occurrence nutber: 039 COUNTY: MISSOULA Township I Range: 019N017W Section: 01 Subsection/additional sections: SW4NE4SW4,SE4NW4SU4 Latitude: 472550 Longitude: 1134244 Elevation: 4190 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 1.25 AIR MILES NORTH OF LINDBERGH LAKE RD., CA. 2.21 AIR MILES WEST OF ST. HWY 83. 15 TABLE IB. (cont.). LINDBERGH LAKE tcont.). Occurrence nuaber: 040 COUNTY: MISSOULA Township & Range: 019N017W Section: 01 Subsection/additional sections: SW4SE4SW4 Latitude: 472539 Longitude: 1134244 Elevation: 4225 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 1.03 AIR MILES NORTH OF LINDBERGH LAKE RD., CA. 2.32 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 041 COUNTY: MISSOULA Township & Range: 019N016W Section: 05 Subsection/additional sections: W2SW4SW4 Latitude: 472541 Longitude: 1134028 Elevation: 4015 USGS Quad: CYGNET LAKE Location: SWAN VALLEY, 0.6 AIR MILES NORTH OF LINDBERGH LAKE RD., 0.53 AIR MILES WEST OF ST. HWY 83. Occurrence nuiber: 042 COUNTY: MISSOULA Township I Range: 019N016W Section: 05 Subsection/additional sections: N2SW4SW4 Latitude: 472544 Longitude: 1134024 Elevation: 3995 US6S Quad: CYGNET LAKE Location: SWAN VALLEY, 0.7 AIR MILES NORTH OF LINDBERGH LAKE RD., 0.43 AIR MILES WEST OF ST. HWY B3. Occurrence nuiber: 049 COUNTY: MISSOULA Township I Range: 019N016W Section: 07 Subsection/additional sections: SW4SW4SE4 Latitude: 472444 Longitude: 1134107 Elevation: 4150 USGS fiuad: CYGNET LAKE Location: SWAN VALLEY, 0.16 AIR MILES SOUTH OF SWAN RIVER, 1.60 there is a possibility that ponds which were surveyed, but which were not observed to support populations, may in fact contain H. aquati 1 is . Future surveys in some or all of these locations would be needed to verify the absence of the species. 18 Callitriche heterophylla (Different-leaved Watei — starwort ) « Equisetum f luviati le (Water Horsetail) Potamoqeton qramineus (Variable Leaf Pondweed) Ranunculus aquati 1 is (Hairleaf Water Buttercup) * Sium suave (Hemlock Water-parsnip) Sparqanium minimum (Small Bui — reed) Other species less frequently found in association with H-_ aquati 1 is include: Alisma plantaqo-aquatica (American Waterplantain ) Alopecurus aequalis (Shortawn Foxtail) Carex atherodes (Slough Sedge) Carex rostrata (Beaked Sedge) Eleocharis palustris (Common Spikesedge) Glyceria borealis (Northern Mannagrass) Myriophyllum spicatum (Spiked Water-milfoil) Nuphar varieqatum (Yellow Water-lily) Phalar is arundinacea (Reed Canarygrass) Ranunculus qmelinii (Gmelin's Buttercup) Saqittaria cuneata (Duckpotato Arrowhead) Typha latifolia (Common Cattail) Utricularia vulgaris (Common Bladderwort) Veronica catenata (Chain Speedwell) 2. TOPOGRAPHY: The topography of the Swan Valley is of glacial origin. Generally, the floor of the valley is level to gently sloping, with drumlins in numerous areas. The pothole ponds in which H. aquati 1 is most often occurs formed upon the retreat of the glacier about 10,000 years ago. These ponds could represent depressions left when masses of ice buried in outwash gravels melted; they could also be formed when areas of ice melted out between areas of outwash sediments which accumulated upon the glacier surface (Alt and Hyndman, 1986). The sites for H. aquati 1 is in Montana range from 945 m (3100 ft.) near the south end of Swan Lake, to 1348 m (4420 ft.) near the east side of Lindbergh Lake. 3. SOIL AND WATER CHEMISTRY RELATIONSHIPS: a. SOIL RELATIONSHIPS: Howell ia aquatilis is found almost exclusively in ponds with bottom surfaces which consist of firm, consolidated clay and organic sediments. Only in two cases were plants found in ponds with deeper, largely unconsolidated bottom sediments; in these situations, most H. aquatilis plants were then found in shallower 19 areas near the shore, in more consolidated portions of the ponds. The texture and depth of these bottom sediments may be very important in relation to seed germination requirements and early growth of H. aquati lis . Loose, silty soil sediments may lead to burial of seeds too deeply to ensure efficient germination and establishment. The soil units which comprise the Swan Valley floor consist of Cryochrepts, Eutroboralf s, and Eutrochrepts. The parent materials for these soils consist of clayey alluvium and clayey colluvium; the resultant soils are deep (Montagne et_ ad. , 1982). The Swan River Oxbow (005) site is unusual in that the H. aquati 1 is populations occupy areas in and near an old, retired oxbow of the previous river channel. The site is physiographical ly very different from the glacial pothole depressions which the species inhabits elsewhere in the Swan Valley. However, the bottom sediments of the sloughs are of a similar consolidated texture, and many of the common associated species are present, especially Carex vesicaria and Equisetum f luviati le . WATER CHEMISTRY: Water samples from nine ponds supporting H. aquati 1 is , and three ponds not supporting the species, were analyzed to determine pH (acidity) and conductivity (ability of an aqueous solution to carry an electric current, depending on the presence, concentration, mobility, valence, and relative concentrations of ions). In addition, five samples (three from H. aquati 1 is ponds, two from others) were analyzed to determine alkalinity (acid- neutralizing capacity). The analyses were conducted by the Montana Department of Health and Environmental Sciences, Chemistry Laboratory Bureau. The results of these analyses are presented in Table E. None of the factors analyzed appear to distinguish among ponds supporting or not supporting H. aouati 1 is . The pH for ponds with or without the species are all in the neutral range (6.75-7.92). It is possible that other factors which were not analyzed are more important in determining the suitability of a particular site for 20 TABLE 2. WATER CHEMISTRY ANALYSES, SWAN VALLEY, LAKE AND MISSOULA COUNTIES, MONTANA. A. Ponds containing Howell ia aquati lis ; Sample (Occ. Number ) A-2 (007) C-l (020) C-3 (027) D-l (008) D-3 (014) (OV?) (018) (031) (051) E-l F-l G-l H-l EM Cond uctivi ty Alkalinity (umho /cm S) 25 s >C> (ma/L as CaC03) 7.20 73 32 7.28 87 44 7.66 266 130 7.57 322 - 7.00 162 - 7.2? 73 - 6.78 68 - 7.13 54 - 6.85 33 - 7.20 126 69 B. Ponds not containing Howel lia aquati 1 is : B-l (near 007) C-2 (near 021) D-2 (near 008) 7.61 6.75 7.92 210 30 216 103 10 7.43 152 56 ai supporting H. aquati 1 is (i.e., dissolved oxygen) . 4. REGIONAL CLIMATE: The climate of the Swan Valley can generally be classified as temperate and moist. Near the distributional area of H. aquati 1 is in Montana, the closest cl imatological stations are located in Bigfork (3010 ft. (918 m.) elevation) and Seeley Lake (4100 ft. ( 1S50 m.) elevation). Data for the period 1951-1980 are provided by the U.S. Department of Commerce (1982). At Bigfork* the mean annual precipitation was 56.08 cm. (22.08 in.); the mean annual temperature was 7.5° C (45.5° F), and the mean July maximum temperature was 27.6° C (81.7° F). At Seeley Lake, the mean annual precipitation was 56.16 cm. (22.11 in.); the mean annual temperature was 5.2° C (41.3° F), and the mean July maximum temperature was 27.8° C (82.0° F). F. POPULATION DEMOGRAPHY AND BIOLOGY 1. PHENOLOGY: The submerged, cleistogamous flowers of H. aquati 1 is are generally formed in May and early June in Montana. The conspicuous emergent flowers are in bloom from late June to August; blooming can actually continue as long as adequate water remains in the vernal ponds which it inhabits. In Washington, emergent flowers have been found in early May. The sites in eastern Washington are probably free of ice much earlier in the growing season. Fruiting begins very soon after the formation of the early cleistogamous flowers in May* and continues as long as blooming proceeds into late summer . 2. POPULATION SIZE AND CONDITION (MONTANA): Because H- aquati 1 is is an annual species which occurs in vernal pothole ponds, its population sizes fluctuate from year to year depending on seasonal conditions. For example, at the Swan River Oxbow (005) site approximately 10,000 plants were observed in 1985, but fewer than 100 plants were seen in 1986 (Lesica et a_L. , 1987a). During field surveys in 1987, the population was very large again, with many hundreds of plants observed. Lesica (pers. comm.) observed approximately 1000 plants in one of the Condon Creek populations (023) in 1986* in 1987, only three plants could be found. Thus, population estimates from one season as may not provide an accurate assessment of the spec ies ' abundance . During field surveys in 1987, the smallest population was at Condon Creek (023): three plants, as mentioned above. The largest estimated population was the Swan River Nest site (007): 3000-4000+ plants. Twelve populations have been found in which the former or recent estimated population size was more than 1000 individuals: Condon Creek (006, 0S0, 030) Lindbergh Lake (OOS, 003, 038, 039, 049) Lost Creek-Cilly Creek Ponds (008, 013) Swan River Oxbow (005) Swan River West (007) Twenty-six populations have been estimated to contain 101-1000 plants, and 14 have been observed to contain 100 or fewer plants. Details regarding population size and condition are summarized in Table 3. REPRODUCTIVE BIOLOGY a. TYPE OF REPRODUCTION: In the submerged, cleistogamous flowers of H. aquati 1 is , the corollas do not develop or open fully, and these flowers are thus strictly self- poll inating . Additional ly , evidence indicates that the emergent, more fully- developed flowers are also self-pollinating (Lesica et aK , 1987b). Thin microscopic sections of emergent flower buds show the anthers to be dehiscing (shedding pollen), and embryos developing, before the corolla is fully developed or open. Additionally, during the course of field surveys in 1987, no pollinators or other insects were observed visiting the emergent flowers, further substantiating the hypothesis that H. aquati 1 is is an obligate self-pollinator. b. SEED DISPERSAL AND BIOLOGY: The seeds of H. aquati 1 is are relatively large, being 2-4 mm. long. They do not possess any wings, appendages, or other structures which appear to provide them with any buoyancy. Though capable of floating on the surface owing to water surface tension, the seeds sink readily when pushed or released below the surface. It is likely that all of the seeds produced 23 TABLE 3. Population size and condition, Hoxellia aquatilis, Missoula and Lake Counties, Montana. Occurrence nuiber: 001 Site naie: LINDBERGH LAKE Acreage: 2 Population size and condition: EST. 75-100+ PLANTS ( 1987) ; NORTH END OF POND IMPACTED BY LOGGING, WITH SOME SLASH PILED INTO THE HATER. Occurrence nuiber: 002 Site naie: LINDBERGH LAKE Acreage: 4 Population size and condition: EST. 2000-3000 PLANTS (1987); NORTH AND WEST MARGINS OF POND DISTURBED BY LOGGING ACTIVITY; DEEPEST POND KNOWN FOR THE SPECIES IN MONTANA (CA. EIGHT FEET); SOME INDIVIDUALS VERY LARGE. Occurrence nuiber: 003 Site naie: LINDBERGH LAKE Acreage: 2 Population size and condition: 1000+ PLANTS (1983); POND IS A SHALL GLACIAL DEPRESSION NEXT TO A LARGER BOG, TO WHICH IT MAY HAVE BEEN CONNECTED EARLIER. Occurrence nuiber: 004 Site naie: LINDBER6H LAKE Acreage: 1 Population size and condition: EST. 11-50 PLANTS (19B3). Occurrence nuiber: 005 Site naie: SWAN RIVER OXBOW Acreage: 30 Population size and condition: VERY COMMON; HAY BE LARGEST OCCURRENCE KNOWN, WITH ABOUT 10000 INDIVIDUALS (1985); ELEMENT OCCURS IN 4 AREAS, IN AND ADJACENT TO THE OLD RIVER OXBOW; MANY HUNDREDS OF PLANTS OBSERVED IN 1987. Occurrence nuiber: 006 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 1000-2000 PLANTS (19B7); MANY PLANTS DISTURBED BY MOOSE AND/OR WATERFOWL ACTIVITY; AREA IS ACTIVELY THREATENED BY LOGGING ROAD CONSTRUCTION AND TIMBER HARVESTING. E<4 TABLE 3. (cont.). Occurrence nuiber: 007 Site naie: SWAN RIVER WEST Acreage: 1 Population size and condition: ABOUT 3000-4000 PLANTS, POSSIBLY MORE; VERY DENSE, AND FORMING HATS, IN WEST POND; THE TWO PONDS, WHICH ARE SEPARATED BY A SALIX BORDER, ARE JOINED BY HIGHER WATER IN THE SPRING. Occurrence nuiber: 008 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: 2 Population size and condition: EST. 2000-3000 PLANTS, IN A SINGLE POND; SURROUNDED BY A RELATIVELY UNDISTURBED FOREST, WHICH WAS REPORTEDLY LIGHTLY SELECTIVELY LOGGED IN ABOUT 1910. Occurrence nutber: 009 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: 3 Population size and condition: EST. 500-600 PLANTS (1987); SPECIES DOES NOT OCCUPY ALL OF THE AVAILABLE, SUITABLE HABITAT AT THIS SITE; AREAS AROUND SOUTH AND EAST SIDES OF POND CLEARCUT CA. 15 YEARS AGO. Occurrence nutber: 010 Site nate: LOST CREEK-CILLY CREEK PONDS Acreage: 2 Population size and condition: EST. 200-300 PLANTS (1987); FLOWERS AND CLEISTOGAHOUS FRUIT; SPECIES DOES NOT OCCUPY ALL OF THE AVAILABLE, SUITABLE HABI- TAT AT THIS SITE; AREAS AROUND SOUTH AND EAST SIDES OF POND CLEARCUT CA. 15 YEARS AGO. Occurrence nuiber: Oil Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: 5 Population size and condition: EST. 100-200 PLANTS (1987), ON SOUTHWEST, NORTH AND EAST MARGINS; PAST LOGGING DISTURBANCE IN THE AREA. Occurrence nuiber: 012 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: 2 Population size and condition: EST. 400-500 PLANTS (1987); MUCH OF POND HAS NO VEGETATION; LOGGING HAS OCCURRED AROUND POND. 25 TABLE 3. (cont.). Occurrence nuiber: 013 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: £ Population size and condition: EST. 1000-1500 PLANTS (1987); L0G6ING HAS OCCURRED AROUND POND. Occurrence nuiber: 014 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: £ Population size and condition: EST. 300-400 PLANTS (1987); L0S6IN6 HAS OCCURRED IN ADJACENT FORESTS. Occurrence nuiber: 015 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: E Population size and condition: EST. 300+ PLANTS U 987)5 LOGGING HAS OCCURRED IN ADJACENT FORESTS; THIS POND WAS DRYING FASTER THAN OTHERS AT THIS SITE. Occurrence nuiber: 016 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: S Population size and condition: EST. 400+ PLANTS (1987); ADJACENT TO LOGGING ROAD. Occurrence nuiber: 017 Site naie: LOST CREEK-CILLY CREEK PONDS Acreage: 3 Population size and condition: EST. 10-1E PLANTS (1987); ADJACENT TO LOGGING ROAD; THIS DEPRESSION WAS MUCH DRYER THAN THE OTHERS, HOWELLIA AQUATILIS PRESENT IN A FEW PUDDLES; HABITAT MAY BE MORE ADVANCED SUCCESSIONALLY THAN NEARBY PONDS. Occurrence nuiber: 018 Site naie: DOG CREEK Acreage: E Population size and condition: EST. S00+ PLANTS (1987); SURROUNDING FOREST LOGGED. Occurrence nuiber: 019 Site naie: D06 CREEK Acreage: S Population size and condition: EST. 150-E00 PLANTS (1987); FOREST IMMEDIATELY SURROUNDING POND IN GOOD CONDITION, FAIRLY UNDISTURBED. E6 TABLE 3. (cont.). Occurrence nuiber: 020 Site naie: CONDON CREEK Acreage: 2 Population size and condition: EST. 1000 PLANTS (1987); NEARBY FORESTS RECENTLY L06GED. Occurrence nuiber: 021 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 50 PLANTS (1987); NEARBY FORESTS RECENTLY LOGGED. Occurrence nuiber: 022 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 200 PLANTS (1987); NEARBY FORESTS RECENTLY LOGGED. Occurrence nuiber: 023 Site naie: CONDON CREEK Acreage: 1 Population size and condition: 3 PLANTS (1987); SEVERAL HUNDRED PLANTS OBSERVED IN 1986 BY P. LESICAJ NEARBY FORESTS RECENTLY LOGGED. Occurrence nuiber: 024 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 30 PLANTS (1987); NEARBY FORESTS RECENTLY LOGGED. Occurrence nuiber: 025 Site naie: CONDON CREEK Acreage: 2 Population size and condition: EST. 25 PLANTS (1987); POND MARGINS RECENTLY DISTURBED BY L066IN6. Occurrence nuiber: 026 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 200-300 PLANTS (1987); NEARBY FORESTS RECENTLY LOGGED. Occurrence nuiber: 027 Site naie: CONDON CREEK Acreage: 2 Population size and condition: EST. 300 PLANTS (1987); SOUTH MARGIN OF POND RECENTLY DIS- TURBED BY LOGGING. E7 TABLE 3. (cont.). Occurrence nuiber: 028 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 200-250 PLANTS (1987); ADJACENT USFS LAND RECENTLY L066ED. Occurrence nuiber: 029 Site naie: CONDON CREEK Acreage: 2 Population size and condition: EST. 200-300 PLANTS (1987); POND MARGINS RECENTLY DISTURBED BY L0S61N6. Occurrence nuiber: 030 Site naie: CONDON CREEK Acreage: 1 Population size and condition: EST. 1000 PLANTS (1987); POND MARGINS RECENTLY DISTURBED BY LOGGING. Occurrence nusber: 031 Site naie: CONDON CREEK Acreage: 2 Population size and condition: EST. 150-175 PLANTS (19B7); AREA DISTURBED BY LOGGING IN THE PAST; POND ADJACENT TO A LOGGING ROAO; PLANTS FOUND IN CALM, SHALLOW AREAS UNDER SHRUBS B0RDERIN6 POND, AND ADJACENT TO LOGS. Occurrence nuiber: 032 Site naie: LINDBERGH LAKE Acreage: 2 Population size and condition: EST. 101-1000 PLANTS (1983). Occurrence nuiber: 033 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 50 PLANTS (1983); THIS SLOUGH HAS A FLOATING SEDGE MAT, AND IS DOMINATED BY TYPHA, AND THUS IS APPARENTLY MORE SUCCESSIONALLY ADVANCED THAN OTHERS IN THE AREA. Occurrence nuiber: 034 Site naie: LINDBER6H LAKE Acreage: 2 Population size and condition: EST. 11-100 PLANTS (1983). as TABLE 3. (cont.). Occurrence nuiber: 035 Site nase: LINDBERGH LAKE Acreage: 2 Population size and condition: EST. 51-1000 PLANTS (19B3). Occurrence nuiber: 036 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 100-125 PLANTS (1987); PLANTS ARE FOUND AT SOUTHEAST END OF POND, ON SECTION LINE. Occurrence nuiber: 037 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 10-15 PLANTS (19B7); POND DISTURBED BY HEAVY L066ING ON ALL SIDES; PLANTS FOUND IN SOUTH END OF POND. Occurrence nuiber: 038 Site naie: LINDBERGH LAKE Acreage: 2 Population size and condition: EST. 1000-1200 PLANTS (1987); POND DISTURBED BY HEAVY LOGGING ON ALL SIDES. Occurrence nuiber: 039 Site naie: LINDBERGH LAKE Acreage: 2 Population sue and condition: EST. 1000-1500 PLANTS (1987); POND DAMAGED BY LOGGING ON NORTHEAST SIDE. Occurrence nuiber: 040 Site naie: LINDBERGH LAKE Acreage: 2 Population size and condition: EST. 300-400 PLANTS (1987); FOREST IMMEDIATELY SURROUNDING POND CURRENTLY UNDISTURBED. Occurrence nuiber: 041 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: FOUR PLANTS (1987); POND AND SURR0UNDIN6 FOREST UNDERSTORY HEAVILY DISTURBED BY LIVESTOCK GRAZING; PLANTS FOUND ON EAST EDGE OF POND. 29 TABLE 3. (cont.). Occurrence nuiber: 042 Site naie: LINDBERGH LAKE Acreage: 3 Population size and condition: EST. 50-60 PLANTS (1987); POND AND SURROUNDING FOREST UNDER- STORY DISTURBED BY LIVESTOCK GRAZING; PLANTS FOUND IN NORTH, NE, AND SOUTH PORTIONS OF POND; HOST PLANTS FOUND IN AN ARM ON NE SIDE OF POND. Occurrence nuiber: 043 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 20-25 PLANTS (1987). Occurrence nuiber: OH Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 275-400 PLANTS U9B7); POND IS ALONGSIDE A HEAVILY USED GRAVEL ROAD, AND IS UNDER A POWER LINE. Occurrence nuiber: 045 Site naie: LINDBER6H LAKE Acreage: 2 Population size and condition: EST. 300 PLANTS (1987). Occurrence nuiber: 046 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 50 PLANTS (1987); ADJACENT AREAS DISTURBED BY CLEARCUT LOGGING. Occurrence nuiber: 047 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 200 PLANTS (1987); POND LOCATED ON EDGE OF A CLEARCUT. Occurrence nuiber: 048 Site naie: LINDBERGH LAKE Acreage: 1 Population size and condition: EST. 250 PLANTS (1987); ADJACENT AREAS DISTURBED BY CLEARCUT L066IN6. 30 TABLE 3. (cont.). Occurrence nuiber: 049 Site nate: LINDBERGH LAKE Acreage: I Population size and condition: EST. 1500-2000 PLANTS (19871; POND IS ON NORTH SIDE OF A NEWLY CONSTRUCTED LOGGING ROAD, JUST NORTH OF USFS BOUNDARY. Occurrence nuiber: 050 Site naie: LINDBERGH LAKE Acreage: 3 Population size and condition: EST. 500-1000 PLANTS (1987); MOSTLY ON THE POND MARGIN, IN THE MORE OPEN ZONE BETWEEN THE EMERGENT VEGETATION AND THE SHORELINE, UNDER OVERHANGING SHRUB COVER; A FEW PLANTS OUT IN DEEPER WATER. Occurrence nuiber: 051 Site naie: LINDBER6H LAKE Acreage: 1 Population size and condition: EST. 100-125 PLANTS (1987); VERY SMALL POND, MOSTLY DRY EX- CEPT FOR CENTER WHERE PLANTS WERE FOUND. Occurrence nuiber: 052 Site naie: KRAFT CREEK Acreage: 1 Population size and condition: EST. 200 PLANTS (19B7); A FEW PLANTS IN MUD ON POND MARGIN STILL FLOWERING ON DATE OF SURVEY; ENTIRE POND NOT SURVEYED. 31 by the submergent c leistogamous flowers sink to the bottom upon release. Although seeds released from emergent capsules could float for a short distance from the point of dispersal , it is likely that these seeds sink fairly soon after release as well. The majority of the populations of H. aquati 1 is occur in ponds which are not connected by drainages or by spring run-off. The exception to this is the Swan River Oxbow (005) site, where the species occurs in four adjacent wetlands on the floodplain of the Swan River. During years of high spring run- off, this area is inundated, and it is likely that these wetlands are thus interconnected. Water from the Swan River was observed flowing through the surrounding forests in June, 1986. In this situation, it is possible that some dispersal of seed by water movement is occurring. Another possible means of seed dispersal for d- aquati 1 is is by wildlife dissemination. Waterfowl were frequently observed in the pothole ponds; it is likely that, when feeding on aquatic vegetation, these birds could ingest H. aquati 1 is and distribute the seeds later in other ponds. Seed movement in pond sediments on their appendages may also occur. This mode of seed dispersal could explain the scattered distribution of the seven sites in the Swan Valley, and the clustered arrangement of adjacent populations at the Lost Creek-Cilly Creek Ponds (008- 017), Dog Creek (018, 019), Condon Creek (020-031), and Lindbergh Lake (001-004, 032- 051) sites. In addition, seed movement by mammals (i.e., deer, bears, moose) also appears to be possible. Deer and moose browse in such ponds, and could thus ingest and transport seeds. Signs of bear foraging were noted at the Lost Creek-Cilly Creek site (008) late in the summer, after all water had dried from the pond; dispersal between ponds could perhaps also occur in this way. Evidence for the presence of a seed bank is reported by Lesica et. aK (1987a). At the Swan River Oxbow (005) site, examination of the surface 3 cm of soil from three 2.25 dm e quadrats in 1986 yielded an estimate of 32 approximately S00 seeds/0J e . The presence of such a seed bank should help buffer the occurrences from periodic environmental fluctuations which result in varying population sizes. G. POPULATION ECOLOGY SUCCESSIONAL RELATIONSHIPS: The pothole ponds inhabited by H. aquatil is appear to be at an early stage within the successional series for such habitats in the Swan Valley. In classifications of wetland habitat types, such ponds could generally be classified as inland shallow fresh marshes (Shaw and Fredine, 1956) or seasonal ponds (Stewart and Kantrudi 1971). Such wetlands are often characterized by aquatic grasses (i.e, Glyceria spp., Alopecurus aequal is ) and sedges (i.e., Carex vesicaria » C. rostrata » C. atherodes ) » pondweeds ( Potamogeton spp.), and burreeds ( Sparqanium spp.) (Ueller, 1981). With increasing sedimentation and accumulation of organic matter, and subsequent lowering of the water table, such habitats can eventually develop into sedge meadows (Reuter, 1986). Numerous examples of such meadows can be found in the Swan Valley, dominated most often by Carex lasiocarpa . In these sedge meadows, the water table is at or below the soil surface; such sites were never observed to support H. aguati lis . The characteristic which may be most important in maintaining the pothole ponds inhabited by H. aguatil is is that they generally always dry completely by the end of the growing season (late August-September). Such drying inhibits the rate of muck accumulation (Reuter, 1986), and may serve to maintain these ponds in an earlier emergent stage. In ponds which are more successional ly advanced, and which may remain wetter for most of the growing season, Typha latifol ia and Nuphar varieqatum are more frequent. Howel 1 ia aguati 1 is occurs in association with T. latifol ia in IS such ponds or wetlands (Condon Creek (031), Dog Creek (018), Lindbergh Lake (004, 012, 032, 033, 037, 040, 042, 046, 047, 048), and Swan River Oxbow (005)) J it is associated with N. varieqatum in three locations (Lost Creek-Cilly Creek Ponds (Oil, 012), Lindbergh lake (047)). In many cases, these ponds were found to support less vigorous populations of H- aguati 1 is , possibly reflecting their advancing successional stage, and increased 33 unconsolidated bottom sediments. 2. COMPETITION: In general, Howell ia aguatilis was observed to occupy less densely vegetated areas within the pothole ponds where it occurs. Two patterns were observed in particular: 1.) in many ponds, the greatest densities of H. aquatil is were found around the pond margins, under the cover of surrounding overhanging shrubs < Sal ix s PP-» ftlnus incana , Cornus stolonifera ) „ In this zone, other emergent aquatic species do not occur in abundance, and H. aguatilis is able to spread throughout such open areas, often growing in thick mats; 2.) in ponds dominated throughout by Carex vesicar ia and/or Equisetum f luviati le > H. aquati 1 is was frequently observed to occupy openings among such vegetation. Similarly, in ponds with open water in the center, H. aquati 1 is was observed to be most dense in such areas. While the species was found to occur amongst the stems of other emergent plants, it was often not as abundant in such situations. These observations suggest that H. aquati 1 is may prefer more open microhabitats within the ponds it occupies, and that it cannot compete vigorously with other aquatic plant species. H. LAND OWNERSHIP (MONTANA) 1. The land ownership for the 52 populations known in Montana is given below. The site names are given, followed by the population occurrence numbers. The exact locations are provided in Table 1, pp. 5-15. a. U.S. Forest Service (Flathead National Forest) : Condon Creek (006, 020-027) Dog Creek (01B, 019) Lindbergh Lake (001, 043-048, 051) Lost Creek-Cilly Creek Ponds (008-017) Swan River West (007) b. U.S. Forest Service (Flathead National Forest) and private land: Lindbergh Lake (036) Swan River Oxbow (005J most of the occurrence 34 is on land recently purchased by The Nature Conservancy) c. Burlington Northern land: Condon Creek (028-031) Lindbergh Lake (002, 037-040) d. Private land holdings: Kraft Creek (052) Lindbergh Lake (003, 004, 032-035, 041, 042, 049, 050) II. ASSESSMENT AND MANAGEMENT RECOMMENDATIONS A. THREATS TO CURRENTLY KNOWN POPULATIONS (MONTANA): The current threats to populations of H. aquati 1 is in Montana are mainly from timber harvest activities occurring adjacent to the pothole ponds which the species occupies. Additionally, some populations are adjacent to gravel logging and public access roads, and are thus susceptible to any road improvement activities which may take place. Lastly, in the vicinity of Lindbergh Lake, some ponds are currently disturbed or potentially threatened by domestic livestock grazing. The sites threatened by these activities are reviewed below: 1. TIMBER HARVEST ACTIVITIES: Of the 52 populations of H. aquati 1 is found in the Swan Valley, 21 occur in ponds around which logging has occurred historically or in the very recent past. In many cases, all coniferous trees were removed down to the pond margins, and the trees left standing were broadleaf deciduous species (i.e., Populus tremuloidesi P. trichocarpa ) . In a few instances, no trees were left bordering some sides of the ponds, and in one case (Lindbergh Lake (001)), logging slash had been placed in the water. Listed below, by site name and occurrence number, are the 21 pond habitats whose margins or immediate surroundings have been physically impacted by timber harvesting. Those which have been very recently impacted (i.e., in 1986-87) are indicated by an asterisk (*). Condon Creek: ♦025 *027 35 ♦029 ♦030 031 Dog Creek : 018 Lindbergh Lake: *001 ooa ♦037 *038 »039 046 047 048 Lost Creek-Cilly Creek Ponds 009-015 (seven ponds) The following populations are located in areas where nearby forests have been logged. Though the habitat immediately surrounding these ponds may still be intact* they are considered vulnerable to further future logging activity. Condon Creek (006, 020, 051, 022, 023, 024, 026, 028) Lindbergh Lake (045) Swan River West (007) One population occurs in an area which has not yet been logged, but in which new logging roads have recently been constructed: Lindbergh Lake (051) 2. ROAD CONSTRUCTION AND MAINTENANCE: The following ponds supporting H. aguati lis occur alongside gravel logging and public access roads: Kraft Creek (052) Lindbergh Lake (004, 033, 036, 044, 049) Lost Creek-Cilly Creek Ponds (016, 017) 3. GRAZING: Two ponds (Lindbergh Lake (041, 042)), located on private land, were found to be heavily 36 impacted by grazing of domestic livestock (esp. horses). Grazing and traversing of these sites has physically disturbed the associated shorelines and vegetation; these sites could also be influenced by changes in nutrient status from livestock bodily wastes. Both of these populations were small: four plants <041)> and 50-60 plants <04S) . Much of the area near Lindbergh Lake is used for open cattle range, especially south of the Swan River. Three populations in this vicinity, on Flathead National Forest land, are in areas currently being used for open range cattle grazing (Lindbergh Lake (046, 047, 048)). Impacts near these ponds were noted, and it is probable that they are used for watering by the livestock. B. MANAGEMENT PRACTICES AND RESPONSE: Despite the fact that H. aquati 1 is occurs over a large geographic area, it is ecologically restricted to a narrowly defined aquatic habitat. Thus, any direct impacts on its habitat are more likely to cause the extirpation of disturbed populations. The species is not one that appears to be capable of colonizing disturbed habitats. The influence of habitat alteration around the ponds could have an effect on their successional trends. In cases where logging has occurred near the habitat margins, an increase in siltation rate into the ponds would be expected. Such a change would probably influence both the nature of the bottom substrates and the vegetational composition of the sites. As discussed above < I.E. 3. a.), H. aquati 1 is occurs most frequently and most densely in ponds with firm* consolidated organic clay bottom sediments. It also is frequently found in more open areas within the ponds. Thus, increases in bottom sedimentation, and subsequent competition from other vegetation, could both have an adverse effect on the viability of H. aquati 1 is populations. Impacts from grazing could also potentially influence the vegetation composition of the ponds* through increased nutrient levels and subsequent successional changes. Also* trampling of the bottom sediments may adversely affect the seed bank* and the consolidated substrate which appears to be necessary for vigorous germination. C. RECOMMENDATIONS FOR MAINTAINING VIABLE POPULATIONS: In order to insure the long-term persistence of viable populations of H. aquati 1 is on U.S. Forest Service 37 lands in Montana, the following recommendations are made: 1 - Protection of habitats which currently support populations. Twenty-nine populations of H. aquatilis have been found on U.S. Forest Service lands. Of these, timber harvesting has occurred around 14 of them: Condon Creek (025, 027) Dog Creek (018) Lindbergh Lake (001, 046, 047, 048) Lost Creek-Cilly Creek Ponds (009-015) The remaining 15 populations occur in relatively intact forest communities: Condon Creek (006, 020-024, 026) Dog Creek (019) Lindbergh Lake (043-045) Lost Creek-Cilly Creek Ponds (008, 016, 017) Swan River West (007) All of these populations should be considered in future land use management plans, i.e., road construction, future timber harvesting, grazing allotments, etc. In addition, since the long- term influences of disturbance adjacent to the ponds are unknown, it is especially important that the undisturbed populations be maintained in their current condition. 2. Notification of U.S. Forest Service personnel of locations of populations on U.S.F.S. lands. To prevent inadvertent impacts to known populations, all appropriate Flathead National Forest personnel should be provided with detailed location information. It is especially important that Ranger District timber sale managers, engineers, and other planners know the precise locations, so that disturbance may be prevented. 3. Evaluation of projects which may affect the hydrology of habitats supporting populations. Because the ponds supporting H. aquati 1 is populations depend largely on run-off for water supply, impacts which may influence this source 38 should be carefully studied. Also, projects which could result in permanent inundation or drying of the ponds should be mitigated. The hydrology of the Swan Valley is highly complex, and H. aquati lis is dependent upon intact drainage patterns. D. RECOMMENDATIONS FOR FURTHER ASSESSMENT 1 • Further surveys in potential habitats in the Swan Val ley , Areas which could possibly support additional populations of H. aquati lis include ponds and wetlands in the vicinity of Glacier Creek, adjacent to the Elk Creek* Kraft Creek* and Windfall Creek drainages (USGS Cygnet Lake and Hemlock Lake 7.5* topographic maps). 2. Establishment of monitoring studies on U.S. Forest Service lands. Owing to the sensitivity of the populations and their habitat* plot studies to determine trends could potentially be quite damaging. However* yearly monitoring studies* to assess general population trends* should be initiated. The most critical populations to be studied in this regard are those 14 in areas disturbed by timber harvesting* discussed in Section II.C.l.* p. 37. Such yearly population checks will hopefully provide some indication of the effects of this land use on the sites. E. SUMMARY: Howell ia aquati 1 is is a monotypic genus with extant populations in Washington and Montana* and historical occurrences in Idaho* Oregon* and California. A total of ten sites are currently known rangewide* many of these consisting of numerous small* adjacent populations. It is a Category 2 candidate species* being considered for listing under the federal Endangered Species Act of 1973 by the U.S. Fish and Wildlife Service. In addition* it is currently a proposed sensitive species in Region 1 of the U.S. Forest Service. Recent studies indicate that the species has no genetic variation within or among populations. Ecological studies reveal that H. aquati 1 is is strictly confined to a narrow habitat type (vernal ponds and sloughs which dry by late summer). These two factors make the species especially vulnerable to habitat alteration or loss. Future land use activities in the vicinity of known populations should be planned with consideration for maintaining them* in order to insure that listing of Howel 1 ia aquati 1 is under the federal Endangered Species Act does not become necessary. 39 ^ III. LITERATURE CITED Alt, D.D., and R.W. Hyndman. 1986. Roadside Geology of Montana. Mountain Press Publ. Co., Missoula. 427 pp. Dorn, R.D. 1984. Vascular Plants of Montana. Mountain West Publishing, Cheyenne, Wyoming. 276 pp. Federal Register. 1985. Endangered and threatened midlife and plants; review of plant taxa for listing as endangered or threatened species; notice of review. September 27, 1985. Fed. Reg. 50 (188): 39525-39584. Bray, A. 1879. Proc. Am. Acad. 15: 43-44. Hitchcock, C.L., A. Cronquist, M. Ownbey, and J.W. Thompson. 1959. Vascular Plants of the Pacific Northwest, Part Four. University of Washington Press, Seattle. 510 pp. Lesica, P., G. Moore, K.M. Peterson, and J.H. Rumely. 1984. Vascular Plants of Limited Distribution in Montana. Monograph No. 2, Montana Academy of Sciences, Supplement to the Proceedings, Vol. 43. 61 pp. Lesica, P., R.F. Leary, and F.W. Allendorf. 1987a. Lack of genie diversity within and among populations of the rare plant, Howel 1 ia aquat i 1 is . Unpublished report to The Nature Conservancy, Helena, Montana. 15 pp. Lesica, P., R.F. Leary, F.W. Allendorf, and D.E. Bilderback. 1987b. Lack of genie diversity within and among populations of an endangered plant, Howel 1 ia aquat i 1 is . Conservation Biology (in review). McCune, B. 1982. Noteworthy collection — Montana. Madrono 29: 123-124. Montagne, C, L.C. Munn, G.A. Nielsen, J.W. Rogers, and H.E. Hunter. 1982. Soils of Montana. Montana Agricultural Experiment Station, Bulletin 744. Montana State University, Bozeman. 95 pp. Munz, P. A. 1959. A California Flora. University of California Press, Berkeley. 1681 pp. Pierce, J., W. Hann, and W. Ruediger. 1987. Federally listed vascular plant species and proposed sensitive plant species list for the Northern Region (draft). U.S. Forest Service, Missoula, Montana. 33 pp. Reuter, D.D. 1986. Sedge meadows of the Upper Midwest: a stewardship summary. Natural Areas J. 6: 27-34.