MONTANA •<%■, STATE This '^over" page added by tha Intarnat Archlva for formatting purposas s 583.57 Nlihaa 1989 MONTANA STATE LIBRARY tHMTNIIM* inic.1tM*> "^^'^liiniiiiTi 3 0664 00082689 4 ADDENDUM TO THE STATUS REVIEW OF Howellia aquatilis U.S.D.A. FOREST SERVICE - REGION 1 FLATHEAD NATIONAL FOREST MONTANA Prepared by: J. Stephen Shelly, Botanist Montana Natural Heritage Program State Library Building 1515 E. 6th Avenue Helena, MT 59620 Order No. 43-0385-8-0677 February 1989 I T ;\ O? I •»-:k- ' »• f,: i l-« ii»-j i . - ^ ^ - ■ • -. «. ! J - . I ■• •*- • • ST'TF dc:(;,m";;ts collect;; ^■■'^ 1 ■ 1S93 f.tC.MTANA STATE L/P^A 'y 1515 E. Ctl. Ave. HELE.NA, MO.'J'A.'JA ■ J-^-, 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 I . INTRODUCTION This report represents an addendum to the status review of Howell ia aquatilis. a sensitive plant species that occurs on the Flathead National Forest (Shelly 1988) . Additional field surveys were conducted during the summer of 1988, in areas on the Flathead National Forest that had not previously been studied. These areas included ponds and wetlands in or adjacent to the Elk, Glacier, and Kraft creek drainages (Missoula County) . Also, surveys were conducted in the vicinity of Salmon Prairie (Lake County) . Sixty-seven sites that had not been previously inventoried were surveyed; of these, three were found to contain previously undocumented populations of ti* aquatilis. This addendum includes maps of the locations of all areas surveyed in 1988, and maps and element occurrence print-outs for the three newly discovered populations. Additionally, monitoring studies were established for five populations (two in the Condon Creek area, and three in the Lost Creek-Cilly Creek area) . These studies consist of transects along which line-intercept data were collected for H. aquatilis and the dominant associated species. The data have been used to estimate the percent cover of these species within the habitats. This addendum includes the initial results, and a preliminary assessment of the suitability of this technique for monitoring population trends and response to management activities. II. SPECIES INFORMATION A. REVIEW OF PRESENT STATUS 1. FEDERAL STATUS: A rangewide status report on il. aquatilis has been prepared for the U.S. Fish and Wildlife Service (Shelly and Moseley 1988). On the basis of information obtained from all five states in which H. aquatilis is historically (OR, CA) or currently (ID, MT, WA) known to occur, and an assessment of Icnown and potential threats to populations, the species was recommended for inclusion in Category 1 of the U.S. Fish and Wildlife Service Notice of Review. Category 1 taxa are those "...for which the Service currently has on file substantial information on biological vulnerability and threat (s) to support the appropriateness of proposing to list them as endangered or threatened species. Presently, data are being gathered concerning precise habitat needs and, for some of the taxa, concerning the precise boundaries for critical habitat designations. Development and publication of proposed rules on these taxa are anticipated..." As of the preparation of this addendum, the U.S. » Fish and Wildlife Service has not issued a decision on this recommendation. 2. STATE STATUS: In Montana, the rank of H. aquatilis has been changed to S2 (6-20 sites in the state) . B. UPDATE OP GEOGRAPHICAL DISTRIBUTION (MONTANA): Prior to 1988, 348 wetland sites in the Swan Valley (Lake and Missoula counties) had been surveyed for the presence of if. aquatilis; the species was found in 52 of them (Shelly 1988). Field surveys were continued in 1988. An additional 67 sites were surveyed, and three new populations were found. Thus, ti. aquatilis is now known from 55 populations, out of a total of 415 wetland sites that have been surveyed. These 55 populations are clustered in nine areas within the Swan Valley. Element occurrence print-outs for the three new locations are provided in Section V, pp. 9-11. The locations of the 67 sites surveyed in 1988, and the three new populations, are indicated on the maps in Section V, pp. 12-15. C. POPULATION DEMOGRAPHY AND MONITORING STUDIES: Details regarding population size and condition for the three newly discovered occurrences are summarized in Table 1. During 1988, monitoring studies were initiated for five populations (occurrence numbers 008, 009, 013, 020, and 027) . The locations of these occurrences are shown in the previous status review (Shelly 1988, pp. 96 and 98). The goals of these studies are 1.) to assess the suitability of the line-transect method for monitoring H. aquatilis. and 2.) to begin collection of information to assess the ecological relationships, and responses to adjacent land use, of the species. METHODS: At each of the five ponds studied, a line- transect was established, using steel posts for the endpoints. The transects varied in length from 42.9 to 50.0 m. Within each pond, they were subjectively placed through portions of the habitat that appeared to be most representative of each occurrence. Measure- ments of the length of canopy coverage bisected by the tape, for H. aquatilis and the major associated species, were recorded to the nearest centimeter. The accumulated length occupied by a species out of the total meter tape length used for the sample is expressed as the percent cover for that species (Mueller-Dombois and Ellenberg 1974) . In addition, photographic slides of each pond were taken (Section VI, p. 16), and measurements of pond depth were made at TAILE 1. Population tltt and condition for Wolwilla igmUJi occurroncM Mirwysd 9r??^li5 - - - 5.43 22.72 ?rundin?