A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern

Abstract

Sequoia and Kings Canyon National Parks are located in the California Floristic Province, which has been named one of world‘s hotspots of endemic biodiversity (Myers et al. 2000). The California Floristic Province is the largest and most important geographic floristic unit in California and extends from the Klamath Mountains of southwestern Oregon to the northwestern portion of Baja California (Hickman 1993). The Sierra Nevada, one of six regions that make up the California Floristic Province, covers nearly 20% of the land in California yet contains over 50% of its flora. Within the Sierra Nevada, the southern Sierra supports more Sierran endemic and rare plant taxa than the central and northern portions of the region (Shevock 1996). Sequoia and Kings Canyon National Parks (SEKI) encompass roughly 20% of the southern Sierra Nevada region. The parks overlap three floristic subregions (central Sierra Nevada High, southern Sierra Nevada High, and southern Sierra Nevada Foothills), and border the Great Basin Floristic Province. The parks support a rich and diverse vascular flora composed of over 1,560 taxa. Of these, 150 taxa are identified as having special status. The term special status is applied here to include taxa that are state or federally listed, rare in California, or at risk because they have a limited distribution. Only one species from these parks is listed under the state or federal Endangered Species Acts ( Carex tompkinsii , Tompkins‘ sedge, is listed as a rare species under the California Endangered Species Act), and one species is under review for federal endangered listing ( Pinus albicaulis , whitebark pine). However, an absence of threatened and endangered species recognized by Endangered Species Acts is not equivalent to an absence of species at risk. There are 83 plant taxa documented as occurring in SEKI that are considered imperiled or vulnerable in the state by the California Department of Fish and Game‘s California Natural Diversity Database (CNDDB 2010a). There are an additional 66 taxa not formally listed by CNDDB that are recognized as having special status because their distribution is restricted to the Sierra Nevada. Special status plants are distributed throughout the two parks and inhabit a wide range of environments along the length of the elevation gradient that characterizes these parks. Ideally, we would assess the condition (status and trends) of each of the taxa on the SEKI special status plant list, documenting current population sizes, demographic rates and demographic trends. We would also hope to quantify the effects of individual stressors on each species based on existing monitoring and research. However, no data are available for most of the species on the special status plant list. For those few species (12 herbaceous species and two tree species) for which we possess some change over time information, the data are not adequate to make a competent assessment. Note that we have not explored the tree demographic information in any detail, as is covered in the NRCA Intact Forest/Five Needle Pines and Sequoia chapters. In general, we are unable to present an ‗integrity‘ metric for special status species in the parks, since the data to quantify the condition of each species in such a manner is not available. In contrast, the park does possess substantial data describing biodiversity in the parks. Therefore, our analysis focuses on describing the distribution and rarity of special status plants within the parks, with a particular focus on assessing the spatial distribution of species richness. We hope that such information will prove useful to park managers in determining which areas in the parks merit the most attention (for example in developing monitoring protocols). We also assess potential vulnerability of special status species to the stressors chosen by the NRCA working group, using both park data and available literature. As a first step, we spent considerable effort updating and refining the criteria for the special status plant list, as this list defines which taxa are considered in our assessment. Observation data of these species was then compiled from all known sources in order to provide a comprehensive view of where special status plants have been documented and, ultimately, to enable the most informed determinations of areas in the parks that potentially support the highest number of rare and endemic taxa. These ‗hot spot‘ analyses are presented by geographic region, vegetation type and elevation. For these and other analyses presented in this report, we place more focus on summarizing findings for the herbaceous and shrub special status taxa than on special status trees. The trees which qualify as special status are the focus of other NRCA chapters, including Giant Sequoia and Intact Forests/Five-needle Pines. We do, however, present their mapped distributions and provide overviews of research related to the special status tree taxa in the Stressors section of this report.