Name:
Juniperus occidentalis / Achnatherum thurberianum Woodland
Reference:
Western Ecology Working Group of...
Description:
These are open woodlands or juniper savannas which are restricted to barren, ashy soils in the central Oregon juniper zone. <i>Juniperus occidentalis / Achnatherum thurberianum (= Stipa thurberiana)</i> woodlands are found on all aspects and slopes, on elevations between 610 and 1370 m (2000-4500 feet). <i>Juniperus occidentalis</i> is the only tree, with the cover ranging from 5-20%. <i>Juniperus occidentalis</i> trees can be very large and quite old, with individuals found to be over 1000 years old in similar habitats in central Oregon. <i>Artemisia tridentata ssp. wyomingensis</i> is common in some areas and absent from others, with cover from 0-40%. <i>Ericameria nauseosa (= Chrysothamnus nauseosus), Salvia dorrii, Peraphyllum ramosissimum, Purshia tridentata</i>, and <i>Atriplex confertifolia</i> are shrubs that can occasionally be found in this type. The understory is dominated by <i>Achnatherum thurberianum</i>, which is always present, at 2-50% cover. <i>Pseudoroegneria spicata</i> is often codominant, especially in stony microsites. In areas with more exposed ash, <i>Hesperostipa comata (= Stipa comata)</i> and <i>Achnatherum hymenoides (= Oryzopsis hymenoides)</i> can also be important, and <i>Poa secunda</i> and <i>Leymus cinereus (= Elymus cinereus)</i> occur. Annual forbs (<i>Mimulus nanus, Eriogonum vimineum, Crocidium multicaule, Collinsia parviflora, Blepharipappus scaber, Cleome platycarpa</i>) and perennial forbs (<i>Balsamorhiza sagittata, Astragalus filipes, Astragalus purshii, Calochortus macrocarpus, Castilleja</i> spp., <i>Erigeron filifolius, Eriogonum umbellatum, Lomatium hendersonii</i>) occur and make the association species rich, but provide very little cover. <br><br>~<i>Juniperus occidentalis / Achnatherum thurberianum</i> Woodland (CEGL002635)$$ is similar to ~<i>Juniperus occidentalis / Pseudoroegneria spicata</i> Wooded Herbaceous Vegetation (CEGL001728)$$, but is distinguished by its lower grass cover, its barren, exposed John Day and Clarno ash soils, and the predominance of <i>Achnatherum thurberianum, Achnatherum hymenoides</i> or <i>Hesperostipa comata</i> in the grass understory.
Accession Code:
VB.CC.32252.CEGL002635
Plot-observations of this Community Concept:
0
|
