METHODS 



Prior to fieldwork, preliminary lists of target plant species were 

 compiled to guide timing and selection of habitats to be searched 

 (Appendix A (MT) , Appendix A (SD) . The Biological Conservation 

 Database (BCD) was queried in the respective state heritage 

 programs to produce copies of existing records that included all 

 known sensitive plant species (USDA Forest Service 1994) and 

 Montana or South Dakota plant species of special concern (Ode 1992, 

 Heidel 1994) on the District or from the surrounding counties that 

 may or may not have potential habitat on the District. Two Montana 

 species of special concern were known from the District (Carex 

 torreyi . Sphenopholis major var. obtusata) neither having sensitive 

 species status. Eight South Dakota species of special concern were 

 known on or adjoining the District ( Aster paucif lorus , Chaenactis 

 douqlasii , Chenopodium subqlabrum , Festuca idahoensis , Gentiana 

 af finis , Haplopappus armerioides , Mertensia ciliata, Penstemon 

 nitidus ) , none having sensitive species status. 



Custer National Forest lands in the Sioux District were surveyed 

 for sensitive plants in the summer of 1994 by Bonnie Heidel (July 

 2-11) and by Keith Dueholm (June 1-July 2, August 23-28). Appendix 

 B shows the primary search routes on maps spanning the study area. 

 Fieldwork by Heidel was concentrated in the north end of the Chalk 

 Buttes and in the South Dakota units. Fieldwork by Dueholm was 

 concentrated in the south end of the Chalk Buttes and remaining 

 Montana units. The fieldwork and accompanying herbarium work is 

 not a comprehensive evaluation but a compilation and sensitive 

 species baseline for reference to be used in subsequent biological 

 assessments and resource planning. 



A wide range of study area habitats and geography was evaluated. 

 Target species were searched for in appropriate habitats focusing 

 at phenologically appropriate times for identification. Existing 

 records were sought to expand the site information, except for 

 occurrences that had been previously documented by the South Dakota 

 Natural Heritage Program. Both uncommon habitats and outstanding 

 examples of typical habitat were included in the survey. 



When plant species of special concern were encountered, standard 

 field forms were filled out (Appendix C) and the locations were 

 marked on U.S.G.S. topographic maps (7.5 1 quads). For each 

 population, data was collected on habitat (associated vegetation, 

 landscape position, geology, soils) , demography and species biology 

 (population numbers, extent, phenology, vigor, reproductive 

 success) , and potential threats to the populations. Photographs 

 (35 mm slides) were taken of the plants and their habitats, and 

 voucher specimens collected as appropriate (Montana Native Plant 

 Society no date) . All specimens will be deposited at major 

 herbaria, including those at the University of Montana (MONTU) , 

 Montana State University (MONT) , the University of South Dakota 

 (SDU) and South Dakota State University (SDC) . 



10 



