A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 8 - alpine environments

Haultain, Sylvia

Sequoia and Kings Canyon National Parks protect most of the subalpine and alpine environment of the southern Sierra Nevada of California. With over 48% of the parks occurring above 3,048 meters (10,000 feet), they are dominated by high elevation habitats. This rugged, remote wilderness is also one of the most scenic landscapes in the world, drawing over 100,000 visitors, largely travelling by foot, each year. Crowning the tops of mountain systems worldwide, the alpine ecosystem is considered quite rare from a global perspective (Heywood 1995) making the protected status of the Sierra Nevada alpine critical to the protection of alpine ecosystems worldwide. In these environmentally extreme and biogeographically isolated highlands, life is tightly constrained by harsh growing conditions. But the alpine is rich in biodiversity. Although at first glance the high peaks and tablelands may appear nearly devoid of life, the alpine flora of the Sierra Nevada includes approximately 600 species of vascular plants (Major and Taylor 1988), with at least 200 of those restricted to the alpine zone (Sharsmith 1940). The Sierra Nevada is in a hotspot of global biodiversity (Myers et al. 2000), so it follows that the Sierra Nevada alpine zone is the most botanically species-rich of the continental alpine environments (Billings 2000). The alpine provides primary habitat for a significant number of sensitive organisms in the two parks, including six of nine recognized at risk or locally extinct animal taxa (American pika, Ochotona princeps; Sierra Nevada red fox, Vulpes vulpes necator; wolverine Gulo gulo; Sierra Nevada bighorn sheep Ovis canadensis sierra; Yosemite toad, Bufo canorus, and mountain yellow-legged frogs, Rana muscosa, R. sierra) and thirty-two of the 150 special status plants (see Sensitive Animal and Sensitive Plants appendices of this report for detailed discussion of these taxa). Dominated by slow-growing perennial plants which are adapted to the extreme climatic conditions that characterize the high elevations, alpine vegetation is thought to be particularly vulnerable to the shifts in temperature and snowpack dynamics predicted under anticipated climate change scenarios. This report provides an overview of the characteristics and extent of the alpine environment in Sequoia and Kings Canyon National Parks, followed by a discussion of the known and potential impacts of each of the key stressors on alpine communities. Because many of the focal resources addressed in this report contain components of, or overlap with the alpine, this section is not meant to be comprehensive, and the reader is frequently directed to other sections for additional detail. Here the term alpine refers to the environment occurring above the treeline at the highest elevations of the Sierra Nevada. The term treeline is used conservatively to include only those high elevation habitats that do not support tree species, regardless of stature. Stands of low-growing krummholz pine (which include whitebark, foxtail, and lodgepole pine in the southern Sierra) are thus excluded from this definition.

A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 8 - alpine environments

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