A Vascular Flora of the Kiavah Wilderness, Scodie Mountains, Kern County, California

Erika Gardner

doi:10.5642/aliso.20173501.02

Abstract

Congress designated the Kiavah Wilderness in 1994 under the California Desert Protection Act. It is located in the Scodie Mountains in Kern County, ca. 24 km (15 mi) east of Lake Isabella and 24 km (15 mi) west of Ridgecrest, and encompasses a total of 137 mi2 (354 km2) with elevations ranging from 1000 to 2200 m (3500–7294 ft). The Wilderness is ecologically important because it occurs in a transition zone between two floristic provinces, the Sierra Nevada of the California Floristic Province and the Mojave Desert of the Desert Province. It is of cultural significance because it has a rich history of Native Americans harvesting pinyon pine nuts and inhabiting the land. Prior to the study ca. 290 vascular plant taxa had been documented, primarily along roads and the Pacific Crest Trail. Jim Shevock and Barbara Ertter made significant collections and contributions to the floristic inventory during the 1980s and early 1990s, and LeRoy Gross added valuable collections in 2005 and 2006. The purpose of the project was to inventory the vascular plant taxa throughout the Kiavah Wilderness, document special status plants, and assess invasive non-native plants. The project took place in 2013–2015, and 68 days were spent in the field. It coincided with three severe to exceptional drought years, the driest span for the site in recorded history. During the study large stands of Pinus monophylla, found in the Wilderness and much of the Southwest, experienced large die-offs. About 1300 plant specimens were collected for the study, which are deposited at RSA, CAS, and UCR. In total, 70 families, 240 genera, 457 species, and 477 minimum-rank taxa were documented, including those collected previously. A total of 28 non-native taxa (5.9% of the flora) and 26 special status plants (5.4%) were documented. Three special status taxa previously documented in the Wilderness were not relocated: Lewisia disepala (Montiaceae), Cordylanthus rigidus subsp. brevibracteatus (Orobanchaceae), and Delphinium purpusii (Ranunculaceae). A range extension for Eriophyllum mohavense (Asteraceae) was documented.

Highlights

Herbarium collections provide invaluable data for researchers studying ecology, biogeography, evolution, systematics and climate change to better understand the patterns of biodiversity and the processes that shape these patterns (Prather et al 2004)
This report is the result of a floristic study conducted over three years that coincided with a severe drought
It is projected that California will continue to experience periods of extended drought throughout the rest of the century (Williams et al 2015)

Summary

INTRODUCTION

Herbarium collections provide invaluable data for researchers studying ecology, biogeography, evolution, systematics and climate change to better understand the patterns of biodiversity and the processes that shape these patterns (Prather et al 2004). The Wilderness covers most of the Scodie Mountains, which is a component range of the southern Sierra Nevada. Major canyons include Bird Spring, Horse, Sage, Boulder and Cow Haven canyons, all of which drain into Indian Wells-Searles Valley (Fig. 2). This watershed provides drinking water to residents of Inyokern and Ridgecrest (EPA 2016). Long-term precipitation data, taken from the Inyokern weather station for 1940–2012, indicate that average annual rainfall was 10.59 cm (4.17 in.) (Fig. 4) This station is at only 760 m (2500 ft) elevation and lies deeper in the rain shadow of the Sierra Nevada.

Schwartzman

CNPS Rare Plant Rank

Findings

California State Rank