don't exceed trace amounts. Stands and stand segments 



were noted where Poa secunda (Sandberg's bluegrass) 



was dominant in place of, or in addition to, Pascopyrum 



smithii, a feature that is likely to be a disturbance 



response. 



[Plots NHMTECRN98SC002 1, 



NHMTECRN98SC0028, NHMTECRN98SC0032] 



Pimts pcmderosa I Carex inops var. heliopMa Woodland 



[PINPON/CARINO] 



Ponderosa pine / sun sedge woodland 



This woodland type of limited extent is found as small 

 patches within breakland or highly dissected and 

 slumpy topography on moderate to steep slopes having 

 cooler exposures. The highly erodible and immature 

 soils are derived from shales. Sheet, rills and gully 

 erosion, as well as plant pedicelling, are evident. This 

 type exists in a mosaic with two other woodland 

 communities; Ponderosa pine (Pinus ponderosa)- 

 dominated patches having such erosive substrates that 

 the undergrowth is virtually absent (< 5% canopy 

 cover) and on cooler aspects small patches of the 

 Douglas-fir / small-seeded indian ricegrass {Pseudotsuga 

 menxksii I Oryzopsis micrantha) association are found. 



Prior to this report, the type has only been identified 

 and described by Hansen and Hoffman (1988) for 

 southeastern Montana and adjacent portions of the 

 Dakotas and by Hoftman and Alexander (1987) for 

 Wyoming. It is notable that this type, as described by 

 the above-cited authors, is outside the distribution 

 liipits of Douglas fir {Pseudotsuga menxiesii). Though 

 the stands on the RNA are dominated by an open 

 canopy of Pinus ponderosa in the uppermost layer, as 

 well as the reproductive layers, these sites are not so 

 severe as to be beyond the limits of Pseudotsuga 

 memjesii establishment and growth. Coring of the 

 largest pine trees {Pinus ponderosa, 14- 16 inches dbh, 38 

 ft. tall) reveals ages of at least 130 years; none of these 

 trees have fire scars. The canopy cover of Rocky 

 Mountain juniper Qurdperus scopulorum) ranges widely 

 but, usually is in the 10-20% range. 



The undergrowth of this association is dominated by 

 graminoids. Shrubs and forbs are poorly represented. 

 Fragrant sumac (Pkus aromatica) and Wood's rose 

 (Rosa woodsii) are consistently present, occurring in 

 trace amounts. Sun sedge (Carex inops) dominates the 

 undergrowth with coverages generally not exceeding 

 30%. This contrasts with its representation in 

 southeastern Montana stands where it is nearly sward- 

 like, coverages mostly exceeding 80%. Bluebunch 

 wheatgrass (Pseudoroegneria spicata) and western 



wheatgrass (Pasco|ryrMm smit/iii) are consistendy present 

 in low coverages. Yarrow (Achillea millifolium) and 

 American vetch {Vicia americana) appear to be the 

 forbs most consistently present. 

 [Plot MHMTECRN98SC0031] 



Populus deltoides I Comus sericeus Temporarily Flooded 



Forest 



[POPDEL/CORSER] 



plains Cottonwood / red-osier dogwood temporarily 



flooded forest 



Note: This stand was sampled direcdy outside of the 

 Refuge within James Kipp Campground area. It had 

 previously been sampled by the Montana Riparian 

 Association (Hansen et al. 1995) ; this data has been 

 weighted heavily in characterizing dogwood as the 

 undergrowth dominant in "natural", undisturbed 

 Cottonwood stands. This stand was sampled to satisfy 

 our curiosity as to the composition and landscape 

 position of a Populus deltoides -dominated stand that 

 differed from all other such stands noted in the RNA. 

 In terms of landscape position, relationship to the 

 watertable and flooding regimes this stand appeared no 

 different than those of the P. deltoides I Symphoicarpos 

 occidentalis association seen upriver from this point. In 

 extensive reconnaissance of the upriver bottomland 

 stands only once did we find a shoot of red-osier 

 dogwood (Comus sericeus). Hansen et al. (1995) 

 interpret POPDEL / SYMOCC as a browsing-induced 

 serai expression of the POPDEL / CORSER 

 community. This may be a plausible explanation for 

 what was observed for Populus deltoides stands on the 

 Missouri River Bottomlands. But it begs the question as 

 to why the James Kipp Campground stand could escape 

 browsing altogether for a period sufficient for Comus 

 sericeus to attain a height putting its foliage beyond the 

 reach of browsers. This stand is also somewhat 

 anomalous in either lacking other shrub species like 

 western serviceberry (Amelanchier alnifoUa, common 

 chokecherry (Prunus virginiana), gooseberry species 

 (Ribes spp.) or having their coverages much below 

 ranges cited as typical for this community type as in the 

 case of Wood's rose (Rosa uioodsii) and western 

 snowberry (Symp/ioricarpos occidentalis). For both the 

 plot and the small examined portion of the total stand, 

 the herbaceous cover was extremely depauperate. 

 Clasping-leaved dogbane (Apocynum sibiricum) was the 

 only forb noted. 



Other Vegetation Types: The shoreline vegetation 

 zones were not briefly described. They often included 

 off-shore emergent bands of Three-square (Scirpus 

 pungens) , water sedge (Carex aquatilis) along the 



27 



