these hay meadows have been sown to exotic species 

 with or without concomitant plowing. In other 

 areas native vegetation is cut. Some sites are 

 probably irrigated. Plowing and seeding almost 

 certainly has adverse effects on native species 

 including C. parryana ssp. idahoa, and may even 

 result in local extirpation. It is not known how 

 annual mowing or irrigation affects C. parryana 

 ssp. idahoa. Some species of Carex persist with 

 annual mowing and irrigation in the Big Hole 

 Valley of Beaverhead County. Further study is 

 needed to determine whether conservation of this 

 rare sedge and haying are compatible. 



3. MINING: A portion of Moose Creek associated with 

 the Moosetown South Carex parryana ssp. idahoa 

 population has been dredged, presumably for 

 mineral extraction. Dredging likely reduced the 

 extent and altered the nature of riparian 

 vegetation and possibly reduced the amount of 

 habitat available to C. parryana ssp. idahoa. 

 Most populations of C. parryana ssp. idahoa do not 

 occur in areas prone to mining activity. 



4. ROADS: Roads are often constructed along or 

 adjacent to riparian areas. Road construction has 

 impacted wetland habitat at three known Carex 

 parryana ssp. idahoa sites: Brundage Creek, 

 Highwood City and Moosetown South. A fourth site 

 (Blacktail Creek) is threatened by road 

 improvement construction. Road development can 

 impact populations of C. parryana ssp. idahoa by 

 reducing the amount of habitat available and by 

 degrading the remaining habitat through increased 

 runoff, pollution, and disturbance from 

 maintenance. 



5. EXOTIC PLANTS: Poa pratensis was the only exotic 

 plant occurring with significant frequency in 

 Carex parryana ssp. idahoa habitat. It is a 

 rhizomatous grass similar in stature to C. 

 parryana ssp. idahoa and may compete with it, 

 especially in the presence of grazing and 

 trampling by livestock. Taraxacum officinale and 

 Tri folium repens occur at some sites, but these 

 small-stature species will increase only in 

 situations where heavy grazing is removing the 

 canopy of larger graminoids. By themselves they 

 do not pose a threat to C. parryana ssp. idahoa. 



B. MANAGEMENT PRACTICES AND RESPONSES 



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