Pinus ponderosa/Pseudoroegneria spicata Plant Association 



PINPON/PSEROE; ponderosa pine/bluebunch wheatgrass 

 MTNHP rank G4/S4 



Environment: This is the most xeric and perhaps the most widespread woodland type on BLM- 

 administered lands in Carter County. It is not restricted to a single landform but is recurrent in a 

 variety of broken topography settings, including the margins of escarpments and breaklands, and 

 scattered knolls, particularly on warm, dry slopes with well-drained soils derived from sandstone, 

 porcellainite, and limestone. It is most extensive in the northern end of the county. 



Vegetation: This woodland type has open stand structure and conspicuous bunchgrass undergrowth; 

 it is described by Hansen and Hoffman (1988) for southeastern Montana. It is included in this report 

 to provide context for the other ponderosa pine communities, though it was not sampled in study 

 plots. 



The PINPON/PSEROE woodland type is present at the perimeter or interstices of most other 

 coniferous woodland types in the county. It is also found apart from them in outlying scattered 

 patches. It is maintained by low-intensity ground fires. 



Comments: It would be valuable to circumscribe the full range of vegetation and environmental 

 characteristics of this type on BLM-administered lands. 



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