Name:
Pacific Coastal Cliff & Bluff Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This macrogroup occurs from the coast of the Aleutian Islands, south through California and possibly into Mexico. It consists of sparsely to moderately densely vegetated sea cliffs, scree slopes and rocky (but not cobble-on-sand) coastlines exposed to salt spray and ocean wave action. The vascular vegetation is typically composed of grasses and low shrubs, which are restricted to small cracks in rock, or slight, sheltered depressions. Lichen cover can be high. In the north, dominants include <i>Aruncus dioicus var. acuminatus, Campanula</i> spp., <i>Carex macrochaeta, Chamerion latifolium, Chamerion latifolium, Deschampsia</i> spp., <i>Fragaria chiloensis, Heuchera glabra, Lupinus nootkatensis, Phegopteris connectilis, Potentilla villosa, Prenanthes alata</i>, and <i>Rhodiola rosea</i>. On Haida Gwaii, <i>Festuca rubra</i> (native subspecies) is a common dominant of rocky headlands. Associated species include <i>Achillea millefolium, Conioselinum gmelinii, Fragaria chiloensis, Maianthemum dilatatum, Mimulus guttatus, Plantago maritima</i>, and <i>Potentilla villosa</i>. However, a wide range of other species may occur and may be dominant in some cases. <i>Picea sitchensis</i> tolerates salt spray and often occupies appropriate microsites on the rocky headlands. They are generally characterized by stunted growth, usually with branches from top to bottom of bole. Lichen cover can be high, but species are poorly described. Coastal bluffs further south, in the Georgia Strait and Puget Sound areas, also have <i>Festuca rubra</i> as a common dominant but associated species include <i>Bromus sitchensis, Grindelia integrifolia, Heuchera micrantha, Plectritis congesta, Sedum</i> spp., and <i>Zigadenus venenosus</i>, among others. Trees, if present, are stunted and/or windblown and may include <i>Arbutus menziesii, Quercus garryana</i>, or <i>Pseudotsuga menziesii</i>. <i>Juniperus maritima</i> may also occur. Shrubs are also infrequent and may include <i>Holodiscus discolor, Amelanchier alnifolia</i>, or <i>Mahonia aquifolium</i>. Mosses can be abundant, including species such as <i>Racomitrium canescens, Polytrichum piliferum</i>, or <i>Dicranum</i> spp. Introduced species are often found, e.g., <i>Aira</i> spp., <i>Cynosurus echinatus</i>, and <i>Cytisus scoparius</i>. Coastal bluff-scrub on the California coastal islands has <i>Artemisia californica, Coreopsis gigantea, Dudleya caespitosa, Dudleya greenei, Eriogonum arborescens, Eriogonum giganteum, Eriogonum grande var. rubescens, Isocoma menziesii, Malacothrix saxatilis var. implicata</i>, and many other species, including many endemic species. This types includes rocky headlands and sea cliffs. Frequent exposure to salt spray distinguishes this macrogroup from inland and alpine rock outcrops and cliffs. Substrates include glacial deposits along the Pacific Ocean. Exposure to waves, eroding and desiccating winds, slope failures, and sheet erosion create rocky substrates that are often unstable. Soils are thin and limited to fine materials blown into cracks and fissures in the bedrock substrate.
Accession Code:
urn:lsid:vegbank.org:commConcept:40477-{4515B27E-104A-4213-AB5F-0D2C2F51EF05}
Plot-observations of this Community Concept:
0
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