In the News

Is Biodiversity an Issue at Lake Tahoe?
date posted: December 22 2005

Lake Tahoe Report #102
Jan. 31, 2005
By John Cobourn and Heather Segale

Though much of the focus of environmental planning and restoration at Lake Tahoe is on water quality, the overall goal is restoration of the Lake Tahoe ecosystem. Both the Tahoe Regional Planning Agency Regional Plan and the USDA Forest Service plan address the need for conservation of natural communities and native species of plants and animals.

When people think of biodiversity, they often think of species that are extinct or are at risk of becoming extinct. For example, the Lahontan cutthroat trout went extinct in Lake Tahoe in the 1930s. Also, the Tahoe yellow cress is a small, fragile, beach plant that grows only at Tahoe and is at risk of extinction.

However, biodiversity is much more than threatened species. Biodiversity exists at three distinct levels. It is the mix of different natural communities, such as forests and meadows, that enrich Tahoe’s landscapes. It is also the distinct array of species within each of these communities. Finally, biodiversity is the genetic diversity within a species that allows it to adapt to changing conditions.

Biologists have identified several important communities that are considered ecologically significant at Lake Tahoe. These include old-growth forest stands, marshes, high-elevation cushion plant communities, shorelines, aspen groves, and riparian areas or stream environment zones. Such communities at Tahoe are likely to be designated for continued protection and restoration.

In addition to local and state agencies, the Tahoe Regional Planning Agency, the USDA Forest Service, and the U.S. Fish and Wildlife Service pay particular attention to the condition of these communities and the species that inhabit them. This is because processes that occur in natural communities, such as photosynthesis, soil development, water cycling, formation of microclimates, and maintenance of the atmosphere, all involve biodiversity. Conservation biologists emphasize that all these processes are critical to the human enterprise.

When species become extremely rare, they are no longer able to be viable players in these critical processes. Thus, the Lake Tahoe Basin Management Unit of the USDA Forest Service has a list of sensitive species on their Web site, http://www.fs.fed.us/r5/ltbmu/about/org/wildlife/. Included are plants such as the Tahoe yellow cress, the Tahoe draba and the Cup Lake draba. Sensitive mammals include the American marten, and sensitive birds include the California spotted owl, northern goshawk, bald eagle, golden eagle, osprey, American peregrine falcon, and willow flycatcher. The Mountain yellow-legged frog, an amphibian, is also a sensitive species and is a candidate for listing by the U.S. Fish and Wildlife Service. Another source of information on rare species is UNR’s Nevada Biodiversity Initiative Web site, http://www.brrc.unr.edu.

Tahoe residents and visitors are fortunate to have such a variety of biodiversity to view and appreciate. One of the challenges of the 21st century is to maintain enough high quality habitat in our changing world to conserve the biodiversity that we and other species depend on for our well-being.