Name:
Arctostaphylos uva-ursi / Festuca campestris - Festuca idahoensis Dwarf-shrubland
Reference:
NatureServe Biotics 2019
Description:
This dwarf-shrubland type is found in the montane to mid-alpine zones of the northern Rockies in northwestern Montana, and extending north into the montane zone of Alberta. The elevation where it occurs ranges almost 790 m (2600 feet), from 1340 to 2130 m (4400-7000 feet), essentially ranging from the montane to the mid-alpine. It occurs on moderate to steep slopes with predominantly southerly exposures, though it has been found on all aspects. This dwarf-shrubland is associated with positions that can be inferred to be wind-battered. It has been recorded exclusively from sedimentary substrates, predominantly limestones and siltstones. These have weathered into thin, fine-textured, and well- to excessively drained soils whose water regime is characterized as predominantly subxeric. The inference that these are stressful sites is borne out in the species composition and structure with the dwarf-shrub <i>Arctostaphylos uva-ursi</i> functioning as the community dominant and other low-shrubs, <i>Juniperus horizontalis, Dasiphora fruticosa ssp. floribunda, Rosa woodsii</i>, and <i>Juniperus communis</i>, being common associates. <i>Arctostaphylos uva-ursi</i> cover ranges from about 5% to as high as 70%, averaging about 30%. <i>Arctostaphylos</i> cover appears to be loosely inversely correlated with cover of the dominant (and diagnostic) grasses, <i>Festuca campestris</i> and <i>Festuca idahoensis</i>, whose average canopy cover hovers around 20-25% and 2-5%, respectively. The only other graminoids with even moderate constancy are <i>Koeleria macrantha</i> and <i>Agoseris glauca</i>, with cover seldom exceeding 5%. High cover values (>30%) for <i>Danthonia parryi</i> characterize higher elevation and relatively mesic stands. Other graminoids present and associated with severe high-elevation sites include <i>Calamagrostis purpurascens</i> and <i>Carex elynoides</i>. The forb component is highly diverse, though individual stands are not as diverse. Forbs present in at least half the stands include <i>Oxytropis sericea, Penstemon confertus, Packera cana, Sedum lanceolatum, Zigadenus elegans, Hedysarum sulphurescens, Galium boreale, Lupinus sericeus, Erigeron caespitosus, Gaillardia aristata, Allium cernuum, Achillea millefolium</i>, and <i>Fragaria virginiana</i>. Cover for any of these is typically low, except the cover of <i>Lupinus sericeus</i> and <i>Hedysarum sulphurescens</i> which tends to exceed 5%.
Accession Code:
urn:lsid:vegbank.org:commConcept:34486-{F9820080-C4E5-46DA-B92D-D9DD586FA347}
Plot-observations of this Community Concept:
0
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