SIERRA NEVADA ECOREGIONAL PLAN December 1999 Photo Courtesy Charles Webber Sierra Nevada Ecoregional Plan 2 Sierra Nevada Ecoregional Plan Sierra Nevada Ecoregional Plan: Craig Mayer Pam Weiant Larry Serpa Christine Tam Robin Cox Jim Gaither 201 Mission Street, 4th Floor San Francisco, CA 94105 (415) 777-0487 3 Sierra Nevada Ecoregional Plan 4 Sierra Nevada Ecoregional Plan TABLE OF CONTENTS 1. Ecoregional Plan A. Executive Summary ……………………………………………….. 7 B. Purpose ……………………………………………………… 9 C. Description of Ecoregion ……………………………………… 9 D. Conservation Issues ……………………………………………… 11 E. Data Sources and Management ……………………………… 11 F. Conservation Targets ……………………………………… 12 G. Conservation Goals ……………………………………………… 12 H. Portfolio Assembly ……………………………………………… 14 I. Portfolio Results ……………………………………………… 15 J. Evaluation of Conservation Lands ………………………………… 25 K. Functional Aggregations …………….……………………………… 25 L. Selecting Action Areas ……………………………………………… 26 2. Analysis and Results by Ecological Group A. Aquatic Systems ……………………………………………… 35 B. Riparian ……………………………………………………… 49 C. Foothill Woodlands ……………………………………………… 61 D. Chaparral ……………………………………………………… 67 E. Montane and Subalpine Coniferous Forests ……………………… 75 F. Interior Wetlands Meadow, and Aspen ……………………… 81 G. Alpine ……………………………………………………… 95 H. Desert Scrub and Woodland ……………………………………… 101 I. Isolated Rare Plants ……………………………………………… 107 J. Common and Widespread Communities ……………………… 111 3. References and Contacts ……………………………………………. 115 4. Appendices ……………………………………………………… 127 Appendix I. Conservation Targets Appendix II. Conservation Goals for Target Communities Appendix III. Portfolio Site Profiles Appendix IV. Site Ranking Score Sheets 5 Sierra Nevada Ecoregional Plan 6 Sierra Nevada Ecoregional Plan A. Executive Summary This ecoregional plan for the Sierra Nevada is presented by The Nature Conservancy of California. Following the guidelines outlined in Geography of Hope (1997), the plan identifies 573 natural areas called “portfolio sites”, whose protection would ensure the long-term survival of viable, vulnerable species and natural communities in the ecoregion. Extending 400 miles from Lake Almanor near Chico in the north to Tehachapi Pass near Bakersfield in the south, the Sierra Nevada ecoregion encompasses some 12 million acres of rugged snow-capped mountains, coniferous forests, and foothill woodlands. Eighty-three percent of the ecoregion is owned and managed by public agencies including 8 national forests, 3 national parks, and numerous state and local lands. The Sierra Nevada ecoregion supports an impressive array of biodiversity including 356 terrestrial vertebrates, 88 vegetation communities, 66 aquatic communities, and 3,500 native plant species. Scientists estimate 17% of terrestrial vertebrate species may be at risk including bighorn sheep, willow flycatcher, spotted owl, and Yosemite toad. Key threats to biodiversity include water development, real estate development, road construction, livestock grazing, fire suppression, and timber harvest. The ecoregional plan evaluates 289 natural communities and species as conservation targets through a series of ecological groups including aquatics; riparian; foothill woodlands; chaparral; coniferous forests; montane meadows, interior wetlands and aspen; alpine; desert woodlands and scrub; isolated rare plants; and common or widespread communities. Data sources include published literature, computer data bases, and expert interviews. The recommended 573 portfolio sites encompass approximately 38% of the ecoregion. Over 100 sites, 20% of the portfolio, are already well-protected in national parks or in ungrazed wilderness areas. An additional 56% of portfolio sites are on other lands owned and managed by public agencies. The remaining 24% of portfolio sites are comprised of mostly private lands. Despite the large number of portfolio sites, many are contiguous or nested together in a way that a majority, 70%, were aggregated into 24 functional units based on proximity, landscape connectivity, and ecological processes. Selection of action areas focused on these functional aggregations since they are inherently large, have a high degree of intactness, and have the greatest potential to conserve biodiversity. Probable action areas in the next five years include four in the northern Sierra (Middle or North Fork American River, Cosumnes River, Perazzo Meadows, and Sierra Valley); and two in the southern Sierra (Kaweah Foothills and Kern River). 7 Sierra Nevada Ecoregional Plan 8 Sierra Nevada Ecoregional Plan B. Purpose With this plan, the Conservancy and our The Nature Conservancy has adopted public and private partners can be confident ecoregion-based planning as the most that site by site conservation activities in the effective way to achieve its mission: to Sierra Nevada are not isolated but part of a preserve the plants, animals, and natural larger, coherent design. communities that represent the diversity of life on Earth by protecting the lands and C. Description of Ecoregion waters they need to survive. This plan The Sierra Nevada Ecoregion is one of follows a methodology outlined in California’s most scenic areas and one of Geography of Hope (1997) that defines a the Nation’s most spectacular natural vision of conservation success at an wonders. A rugged mountainous area of ecoregional scale. It is based on the design snow-capped granite peaks, glacier-carved of a “portfolio” of biologically outstanding valleys, and dense coniferous forests, it is sites, systematically defined to fully exemplified by places like Yosemite and represent the natural communities and Sequoia National Parks, Lake Tahoe, and species of the ecoregion, in combinations 14,495 foot Mount Whitney – the highest that maximize efficiency. peak in the United States outside Alaska. Figure 1.1 Ecoregional planning in Figure 1.2: Sierra Nevada Ecoregion California The ecoregion encompasses a northwest The Sierra Nevada is the fourth ecoregion trending mountain range extending some the Conservancy has studied in California 400 miles from Lake Alamnor in the north following the South Coast, the Central to Tehachapi Pass near Bakersfield in the Coast, and the Central Valley (Figure 1.1). south (Figure 1.2). The ecoregion is 50-80 9 Sierra Nevada Ecoregional Plan miles wide and is generally bounded by the ecoregion. More than 400 species of plants 3,000 ft (900 m) elevation on the west and are thought to be endemic to the Sierra the 5,000 ft (1,500 m) elevation on the east. Nevada. It is a landscape of some 12 million acres. In general, vegetation is stratified into Larger than New Hampshire and Vermont distinct north-south bands along the axis of combined, the Sierra Nevada includes the Sierra Nevada reflecting elevation and portions of eighteen counties in California moisture gradients (Figure 1.3). The foothill and two in Nevada. Eighty-three percent of zone on the west slope from about 1,000 to the ecoregion is in public ownership 3,000 ft (300 to 900 m) is comprised of including 8 national forests, 3 national broad-leaved woodlands and evergreen parks, large areas of Bureau of Land shrublands such as blue oak and interior live Management (BLM) land, and numerous oak series. The montane zone from 2,000 to state and local lands. 7,000 ft (750 to 2,100 m) is characterized by coniferous forests such as ponderosa pine The climate varies with elevation, ranging and mixed conifer communities. The from rainy winters and hot dry summers in subalpine zone ranges from 7,000 to 11,000 the western foothills to cold snowy winters ft (2,100 to 3,300 m) and includes red fir, and cool summers at higher elevations. white fir, mountain hemlock, and lodgepole Temperatures average 35 to 52F (2 to 11C) series. Above timberline, the alpine zone is but fall with increasing elevation. Winter characterized by bare rock, permanent snow precipitation makes up to 80 to 85% of the fields, and low graminoid or forb species. total, much of it in the form of snow at Desert-facing slopes on the east side of the higher elevations. The western foothills Sierra Nevada below 7,000 ft (2,000 m) are receive only 10 to 15 inches (250 to 380 more arid and include pinyon-juniper mm) of rainfall per year and have a long, woodlands and sagebrush communities. unbroken dry summer season. At higher elevations, the dry summer season is shorter and total precipitation rises to as much as 70 inches (1,790 mm). Prevailing west winds influence climatic conditions for the whole region creating a rain-shadow effect along the eastern slope. The ecoregion supports an impressive amount of biological diversity. The California Wildlife Habitat Relationships (WHR) model, estimates about 356 species Figure 1.3: Typical cross-section of the of terrestrial vertebrates utilize the Sierra Sierra Nevada Nevada ecoregion as a significant portion of their range. The California GAP analysis Common large mammals include mule and identifies 88 Holland (1986) natural black-tailed deer, black bear, mountain lion, vegetation communities and the Sierra and coyote. Common smaller mammals Nevada Ecosystem Project (SNEP 1996) include golden-mantled ground squirrel, identifies 66 aquatic communities, defined long-eared chipmunk, and porcupine. by Moyle and Ellison (1991), in the Common birds are acorn woodpecker, Williamson’s sapsucker, mountain 10 Sierra Nevada Ecoregional Plan chickadee, and Cassin’s finch. Declining • Fire suppression has altered fire regimes wildlife species include bighorn sheep, resulting in an increased density