Jordan Crater Research Natural Area

Vale District , BLM

Northern Basin and Range Ecoregion

Cell(s):

• Basin big sagebrush/bluebunch wheatgrass
• Threetip sagebrush/Idaho fescue
• Silver sagebrush/bluegrass flat or playa
• Low elevation lake with aquatic beds and marshy shore
• Low elevation vernal pond
• Bulrush-cattail marsh, with aquatic beds

Access by gravel and low standard dirt-clay roads passable from spring to fall, when dry.

The 12,703 ha Jordan Crater RNA is northwest of Jordan Valley in Malheur County of southeastern Oregon. The RNA was established because its terrain is characterized by young basaltic extrusions dated between 4,000 and 10,000 B.P. consisting of mainly smooth pahoehoe type lava, with some areas of rough aa lava. A series of natural freshwater ponds within the lava provide habitat for a concentrated and rich fauna. The RNA protects three special status species: pale western big-eared bat (Corynorhinus townsendii pallescens), American white pelican (Pelecanus erythrorhynchos), and annual dropseed (Muhlenbergia minutissima). Within the RNA, the slope falls gently to the east (1,400 to 1,310 m), but the surface of the lava flow is irregular with numerous domes, cracks, and sinks. Soils vary from lacking on the lava flows to shallow and stony on the perimeter. Vegetation on the lava flows consists mainly of mosses and lichens with most plant communities at the perimeter of the lava and around the ponds, where organic matter has accumulated. Two small kipukas, islands of virtually undisturbed native sagebrush/grasslands, are found within the lava flow. Near the playas, the major plant communities are big sagebrush/bluebunch wheatgrass (Artemisia tridentata/Pseudoroegneria spicatum) and silver sagebrush/nevada bluegrass (Artemisia cana/Poa nevadensis = Poa secunda). The lacustrine and palustrine wetlands include low elevation lake vegetation with aquatic beds and a marshy shore, low elevation vernal pond vegetation, and bulrush-cattail marsh with aquatic beds. Lithic, Xerollic and Haplargids soil families are present. Long term average precipitation in this cold desert climate is 28 cm per year. Livestock grazing has occurred on the perimeter of the RNA since the 1860s. In the mid-1960s portions of the rangeland area were treated with the herbicide 2,4-D and seeded with crested wheatgrass (Agropyron cristatum or A. desertorum). For the most part, the remote and inaccessible location of the RNA has minimized human disturbance. Wildfires have burned along the margin of the lava flow. Robert Kindschy has written a guide book, Jordan Craters Research Supplement 7 (1978). Past studies include Field Notes (Robert Kindschy) from 1960 - present, Response of Red Willow to Use by Beaver, Robert Kindschy, 1989; Pristine Vegetation of the Jordan Craters Kipukas, 1978-91, in press.