Whippoorwill Flat

The area covers 3328 acres (1347 ha). Elevations range from about 6800 ft (2073 m) in the northeast corner of the area to 11,123 ft (3390 m) atop Waucoba Mountain. The area occupies the east flanks and upper bajada slopes of Squaw Peak (10,358 ft, 3157 m) and Waucoba Mountain. Topography is steep and rugged on the upper slopes of the mountains, but it becomes moderate to gradual on the lower slopes.

Distinctive Features 

Dense, Well-Developed Pinyon Forest: The granitic alluvium in the east-central portion of the RNA appears to be optimal substrate for single-leaf pinyon pine. Numerous specimen trees exist with single, straight trunks and spreading crowns. Growth rates are relatively rapid (16 inches [41 cm] dbh in 100 years), and densities are high. The high density and large stature of the pinyon pines provide an excellent habitat for many animal species, some not typically found in high numbers in pinyon associations. For example, gray flycatchers (Empidonax wrightii), hermit thrushes (Catharus guttatus), western tanagers (Piranga ludoviciana), mountain chickadees (Parus gambeli), and pinyon mice (Peromyscus truei) are notable for their high densities. 

Substrate Differences: The diverse rock types, ranging from granite through shale and limestone, provide a backdrop for comparative work on ecological amplitudes of many species within several communities of the Great Basin mountains, including bristlecone pine (Pinus longaeva) forest, sagebrush scrub, pinyon forest, and Cercocarpus scrub.

Effect of Climate on Vegetation Types: Although the area is notable for its large area of contact between the bristlecone-limber pine forest and the pinyon-juniper zone, several small bare zones – largely uncolonized by trees – separate the two coniferous associations. Upon close inspection, it appears that these zones, with a tendency towards northeast exposures, are a dynamic boundary between the two associations. At present, dead stems of limber and bristlecone pines are scattered through these bare patches, many dead and dying bristlecones and limbers occur above the bare areas, and numerous young pinyons occur at the lower edges of them. This suggests that over the past several hundred years there has been a trend for the local subalpine forest to retreat upslope, while pinyon forest has advanced somewhat to replace it. The long persistence of stands of dead bristlecone pine stems elsewhere has been shown to indicate climatic change (LaMarche and Mooney 1967, Mooney 1973).

Archeological: Pinyon pine nuts, in large supply in the dense forest on the east side of the RNA, were an important source of food for the Paiute and Shoshone Indians. Many signs of their inhabitance have been discovered including wickiup circles, obsidian chips and tools, pinyon-nut storage cairns, and so forth. The name Waucoba (from the prominent mountain along the west boundary of the RNA) means “pine” in Paiute.

Association Types 

Seven 100-m² plots were sampled in the dense pinyon forest, and three 100-m² plots were sampled in the mixed pinyon-juniper phase. 

Pinyon Forest and Pinyon-Juniper Woodland (72122, 72121): 1954 acres (791 ha). This association may be divided into two types: a mixed Pinus monophylla and Juniperus osteosperma woodland on the slopes and ridges underlain by Wyman formation and Papoose Flat granite, and a Pinus monophylla forest phase on the granitic alluvium in sections 25 and 36. 

The sample from the dense pinyon forest on the alluvium has an average density of 730 pinyon pines/ha. Ten shrubs are typical of this association, the most important of which are Artemisia tridentata, Lupinus palmeri, Ribes velutinum var. glanduliferum, Opuntia erinacea var. erinacea, and Chrysothamnus viscidiflorus. Thirty species of grasses and herbs are enumerated in the sample, with such species as Gilia ophthalmoides, Cryptantha echinella, Mimulus densus, Gayophytum diffusum ssp. parviflorum, Lomatium nevadense, Poa sp., Sitanion hystrix, Eriogonum panimentense, Cryptantha flavoculata, and Erysimum capitatum among the most frequent. 

In the typical pinyon-juniper phase, pinyon pine dominates over juniper at a ratio of about 2:3. Total density of stems (including multiple trunks of juniper) on the small sample is 930 trees/ha. However, most areas appear substantially lower in density than the sample. Typical shrubs include Artemisia arbuscula ssp. nova, Chrysothamnus nauseosus, Ribes velutinum var. glanduliferum, and Opuntia erinacea. Herbs include Penstemon floridus ssp. austinae, Petalostemum searlsiae, Gilia ophthalmoides, Cordylanthus helleri, Stanleya elata, and Astragalus minthorniae var. villosus.

Sizes of the typical mature pinyon pine on the alluvium are 16-20 inches (41-51 cm) dbh and 35-45 ft (11-14 m) tall. These trees range between 100 and 150 years with occasional dominants slightly more than 200 years. Reproduction of both types of trees is good. 

Nearly the entire elevational range of the local pinyon association is represented. At the northeast corner of the area, the pinyon-juniper association gives way to the sagebrush scrub of lower elevations, whereas between 8300 and 8600 ft (2530-2621 m), the pinyon forest commonly grades abruptly into the bristlecone-limber pine forest (on northern exposures) or Cercocarpus scrub (on southern exposures).

Bristlecone-Limber Pine Forest (86400, 86700): 711 acres (288 ha). This association covers the upper slopes of Squaw Peak and Waucoba Mountain and north-facing limestone canyons from summits to about 8800 ft (2682 m) (as low as 8300 ft, 2530 m, in the canyon between Squaw Peak and Waucoba Mountain). Bristlecone pine dominates on steep north-facing exposures, and limber pine tends to dominate on more gently sloping exposures. The two species also form extensive mixed forests on the upper east exposures of Waucoba Mountain and on the northeast slope of Squaw Peak. Both species are replaced by sagebrush scrub on the exposed summits of Waucoba Mountain and Squaw Peak and tend to occur primarily on east- and north- facing slopes. At the lowest elevations, bristlecone pine appears restricted to calcareous soils. However, at upper elevations on Waucoba Mountain bristlecone pine grows exceptionally well on granitic soils. 

No sampling was conducted in these forests. Tree densities are estimated as averaging between 300 and 700 trees/ha. Many of the limber and bristlecone pines are moderate-aged and reproducing well. The largest bristlecones noted are about 60 inches (1.5 m) dbh. No tree ring studies have been made, but a number of trees, particularly on the exposed lower south slopes of Squaw Peak, appear to be at least in the 3000-year-old range. The largest limber pines are 40- 44 inches (1-1.1 m) dbh. Typical canopy height is 40-45 ft (12-14 m) with dominants of both species up to 55 ft (17 m). The understory is moderately sparse to very sparse with occasional Ribes cereum, Cercocarpus ledifolius, Artemisia tridentate, and scattered subalpine herbs in low duff areas. Fire charring from lightning strikes is common, but fires rarely spread beyond one or a few trees, owing to the light duff and open understory.

Sagebrush Scrub (35210, 35220): 476 acres (193 ha). This association varies somewhat, depending on soil depth, substrate, and elevation. In general, however, it is dominated by either Artemisia tridentata (on deeper soils) or Artemisia arbuscula ssp. nova (shallower and calcareous soils) with Purshia glandulosa, Ephedra viridis, Chrysothamnus viscidiflorus ssp. viscidiflorus, Chrysothamnus viscidiflorus ssp. pumilus, and Chrysothamnus nausiosus ssp. albicaulis. At low and mid-elevations herbs include Eriastrum wilcoxii, Gilia ophthalmoides, Eriogonum panamintense, Allium atrorubens var. inyoensis, Astragalus minthorniae, Lomatium nevadense, Mentzelia montana, Calyptridium roseum, Penstemon confusus, Cryptantha circumscissa, C. watsonii, Arabis holboellii var. retrofracta, Oxytheca dendroidea, and Sphaeralcea ambigua. 

The high-elevation sagebrush scrub on the summits of Squaw and Waucoba has many subalpine herb species intermixed and may be considered subalpine sagebrush scrub (Holland 35220). This phase covers 114 acres (46 ha) and includes such species as Astragalus lentiginosus var. semotus, A. calycosus, Cymopterus cinerarius, Oxytropis viscida, Erigeron clokeyi, Arenaria nuttallii ssp. gracilis, Eriogonum ovalifolium var. nivale, Castilleja nana, Artemisia norvegica var. saxatilis, and Ipomopsis congesta ssp. montana. 

Density of shrubs and herbs varies, with the lowest elevation and deepest soil stands typically having the highest shrub density while the subalpine ridgetop stands maintain lowest densities.

Cercocarpus Scrub (no Holland equivalent): 187 acres (76 ha). This minor association covers the upper rocky slopes of Squaw Peak and Waucoba Mountain on harsh southern and western exposures as well as a few low-elevation outcrops of limestone in the east portion of section 36. Cercocarpus ledifolius dominates on most sites except dry limestone or marble outcrops where C. intricatus is important. Shrub densities may be open to dense depending on slope steepness and rockiness. Associated species are relatively few and include Chamaebatiaria millefolium, Holodiscus microphyllus, and Ribes cereum. At lower elevations Juniperus osteosperma and occasional Pinus monophylla may occur with the mountain mahoganies and Tetradymia canescens, Artemisia arbuscula, Eriogonum heermannii, Astragalus calycosus, A. purshii var. tinctus, and Cryptantha confertiflora. 

At higher elevations such as the saddle between Squaw Peak and Waucoba Mountain, more subalpine species such as Lesquerella kingii, Trifolium andersonii ssp. monoense, Erigeron clokeyi, Ipomopsis congesta ssp. montana, Stipa comata, Poa epilis, P. incurva, and Sitanion hystrix occur.

Plant Diversity 

One hundred forty-five species are listed. 

Conflicting impacts 

Feral burros had an impact on the shrubby and herbaceous vegetation before the late 1970s, but they have been controlled, with good vegetation recovery. Some woodcutting and prospecting have taken place in the area adjacent to two poorly maintained dirt roads that just enter the extreme east portion of the area. Litter and other disturbance around informal campgrounds are minimal.