"We can solve most of the problems of the Sierra but we must act soon"
DAVIS -- A major study of the Sierra Nevada indicates that much of the mountain range is in fairly good health now but rapid population growth, ongoing neglect and pollution from the Central Valley threaten the future of the region's forests, species diversity, and air and water quality.
The three-year, $6.5 million Sierra Nevada Ecosystem Project (SNEP), requested by Congress and funded primarily by the U.S. Forest Service, is the most exhaustive study ever done on the 400-mile-long mountain range. The just-released final report on the project -- produced by a large team of scientists and researchers from public universities, resource agencies and independent consulting firms -- assesses the ecological, economic and social conditions in the Sierra Nevada and offers management options to enhance the region.
"This study raises our understanding of the Sierra Nevada to a new level," said Don Erman, the SNEP science team leader and University of California, Davis professor of wildlife, fish and conservation biology. "We can solve most of the problems of the Sierra but we, as a society, must act soon. The options available to us to ensure the long-term sustainability of this national treasure will begin to close down rapidly."
Along the west side, ozone and small particulates from Central Valley sources creep up the mountainside, resulting in some of the worst air quality in the nation
scientists devoted most of their efforts to analyzing existing information rather than conducting new studies or experiments. "Critical findings" are catalogued early in the 3,000-page report according to subject headings, such as people and resources, institutions, fire and fuels, plants and wildlife, old growth forests, rangelands and grazing, watersheds and aquatic organisms, and air quality. Key findings include:
Aquatic and associated riparian systems are the most altered and impaired habitats in the Sierra. Chinook salmon and steelhead, which once ran in most of the major Sierran streams, have been nearly eliminated from the range due to dams and impoundments. Once extensive and abundant populations of frogs and salamanders have suffered extensive local extinctions and are threatened rangewide, especially in high elevations where stocking programs fill mountain lakes with non-native fish. Continuing threats to water quality include sedimentation, mercury contamination, biological pathogens such as giardia and increased salinity.
"Late successional" or "old growth" forests have been drastically reduced by a variety of human activities, including timber harvesting, indiscriminate burning in the 19th century and fire suppression in this century. Most of the remaining Sierran late successional forests are found primarily in four national parks -- Lassen Volcanic, Yosemite, Sequoia and Kings Canyon. A relatively high level of continuous forest cover, although greatly simplified in structure, still exists throughout most of the Sierra. Large clearcuts are uncommon. High levels of bark beetle infestations in pine and fir forests, especially those in the Tahoe Basin and along the Sierra's eastern slope, have been exacerbated by fire suppression and past forestry practices.
Air quality in the Sierra represents both extremes. At times, the air quality in the northern Sierra Nevada is among the cleanest in the world. But farther south along the west side, ozone and small particulates from Central Valley sources creep up the mountainside, resulting in some of the worst air quality in the nation. Extensive damage to sensitive tree species is occurring at low and middle elevations. On the eastern side of the Sierra, dust storms arising from Owens Lake create severe episodic health hazards.
Plant diversity in the Sierra is enormous -- more than 3,500 species of plants (about half the state's total) exist in the 88 primary vegetation types found throughout the Sierra Nevada. The biggest threats to the integrity of these plant communities are human settlement, livestock grazing and fire suppression. Oak woodlands and other plant communities in the foothill region have been converted at an "alarming rate" in the last century and are most at risk of loss by conversion to human settlement. The native perennial understory in these plant communities were mostly replaced in the last century by introduced annual grasses and herbs.
Terrestrial vertebrates -- mammals, birds, reptiles and amphibians -- number about 400 species in the Sierra. Many depend on the presence of large old trees, snags and logs and riparian habitat in Sierran woodland and forest communities for some part of their lifecycle. Sixty-nine species of terrestrial vertebrates (17 percent of the Sierra fauna) are considered at risk by state or federal agencies listing them as endangered, threatened, of "special concern" or "sensitive." Species perilously in decline include bighorn mountain sheep, Yosemite toad, foothill yellow-legged frog, western pond turtle, California horned lizard, willow flycatcher and olive-sided flycatcher. Three native species once common in the Sierra Nevada are no longer found there -- grizzly bear, Bell's vireo and California condor. Fifteen non-native species of terrestrial vertebrates are now well-established in the Sierra, including the brown-headed cowbird implicated in the decline of several Sierran songbirds.
Human settlement in the Sierra Nevada is taking place at a rapid pace. As of 1990 an estimated 650,000 people lived in the Sierra Nevada, with 70 percent of that population located in the foothills of the west side. Projections suggest that by the year 2040, the population of the Sierra Nevada will swell to between 1.5 and 2.4 million people. These new residents are likely to be retirees, commuters and other ex-urban migrants. Employment in traditional resource-extraction industries -- agriculture, timber and mining -- is declining. Recreation and tourism now provide more jobs and roughly the same total amount of wages as all the commodity-based sectors combined.
Community well-being, as measured by socioeconomic status and other factors, is highly variable. Pockets of poverty are found more frequently at lower elevations but are scattered throughout the region. The Lake Tahoe region displays the most dramatic unequal distribution of wealth: 40 percent of the permanent basin population resides in communities with low or very low socioeconomic status, while 47 percent reside in communities with high or very high socioeconomic status. In general, the Sierra's poorest citizens tend to live in towns with populations of more than 10,000.
Fire suppression efforts and past timber harvesting practices, have contributed to a dangerous accumulation of fuel on the forest floor. Continuing urban settlement, especially along the western slope of the central Sierra Nevada foothills, places an increasing number of homes and people at high risk. These trends are "incompatible" without active fuels management and changes in forest practices.
"The beginning is to acknowledge that problems exist"
The SNEP study
and final report differs from most other environmental assessments in that the strategies explored are not fully analyzed alternative management schemes, nor does any one strategy address all aspects of the ecosystem. Rather, they are potential components of regional or rangewide alternatives yet to be formulated. Sierra-wide approaches, such as Areas of Late Successional Emphasis to enhance old growth characteristics of Sierran forests or biodiversity management areas are offered in the report as strategies to ensure an optimal level of species habitat and diversity. These strategies would necessarily cut across jurisdictional boundaries in order to be effective.
"The view of the Sierra as a whole system, or a web of biological and social influences stretching over time, suggests that no easy policy or technical fix' can be implemented in the Sierra Nevada," the report states. "Many institutions will absorb, elaborate and recast SNEP strategies to find solutions."
Collaboration among various agencies, private interests and the public at large in the Sierra is the most significant principle that emerges from the SNEP strategies, the report concludes. "As they collaborate, agencies, private landowners and the public begin to function as interacting parts of a whole system, and the number of ways to balance use and environmental quality increases exponentially."
The analysis of the Sierra was requested in the 1993 Congressional bill H.R. 5503, which authorized a scientific review of the remaining old growth in the national forests of the Sierra Nevada and a study of the entire ecosystem by an independent panel of scientists. The University of California’s systemwide Centers for Water and Wildland Resources managed the study under a cooperative research agreement with the U.S. Forest Service, Pacific Southwest Research Station. Erman is also director of the centers.
Public involvement was an important component of SNEP. Seventy people with diverse interests and responsibilities in the Sierra were assembled as "key contacts." This group met with the team to review progress, ask questions, help in framing strategies, assist in review of assessments and plan larger public involvement.
"The beginning is to acknowledge that problems exist," Erman said. "The Sierra Nevada Ecosystem Project has done that in a way that can empower the public to take appropriate measures through existing institutions. We must, however, be willing to form new collaborations among public entities and individual citizens to achieve mutually desirable goals. Willing minds and able hands can find the solutions."