table of contrents Sierra Nevada Forest Plan Amendment – Part 4.6 4.6. Vascular Plants, Bryophytes, and Fungi4.6. Fungi Introduction Part 3.1 of this chapter describes landscape-scale vegetation patterns. Part 3.2 describes the vegetative structure, function, and composition of old forest ecosystems, while Part 3.3 describes hardwood ecosystems and Part 3.4 describes aquatic, riparian, and meadow ecosystems. This part focuses on botanical diversity in the Sierra Nevada, beginning with an overview of botanical resources and then presenting a more detailed analysis of the rarest elements of the flora, the threatened, endangered, and sensitive (TES) plants. The bryophytes (mosses and liverworts), lichens, and fungi of the Sierra have been little studied in comparison to the vascular flora. In the Pacific Northwest, studies of these groups have received increased attention due to the President’s Northwest Forest Plan. New and valuable scientific data is being revealed, some of which may apply to species in the Sierra Nevada. This section presents an overview of the vascular plant flora, followed by summaries of what is generally known about bryophytes, lichens, and fungi in the Sierra Nevada. Environmental Consequences of the alternatives are only analyzed for the Threatened, Endangered, and Sensitive plants, which include vascular plants, several bryophytes, and one species of lichen. 4.6.1. Vascular plants4.6.1. plants The diversity of topography, geology, and elevation in the Sierra Nevada combine to create a remarkably diverse flora (see Section 3.1 for an overview of landscape patterns and vegetation dynamics in the Sierra Nevada). More than half of the approximately 5,000 native vascular plant species in California occur in the Sierra Nevada, despite the fact that the range contains less than 20 percent of the state’s land base (Shevock 1996). The Sierra Nevada has long been recognized for its rich endemic flora, important both for the persistence of relict species and for the evolution of new species (Raven and Axelrod 1978). The largest and most dominant organisms within each major vegetation type are the vascular plants - this is especially striking in old forest ecosystems where the largest trees may tower over 250 feet and have life spans over 1,000 years. Vascular plants are defined as those that contain conducting or vascular tissue. They include seed-bearing plants (flowering plants and conifers) and spore-bearing forms, such as ferns. They create the structure of the forest and function as the primary producers, capturing sunlight through photosynthesis and converting it to food consumed by animals and fungi. Vascular plants provide substrate and habitat for other organisms; influence microclimate (such as sunlight, humidity, and temperature); and provide forage, hiding, and thermal cover for vertebrate and invertebrate species. They produce litter fall that contributes to organic matter and soil development. Some species are symbiotic with fungi and other vascular plants, while others fix nitrogen. Trees with dwarf mistletoe develop broom-like structures that function as nesting platforms for birds and small mammals. Many vascular plants have close relationships with specific animal pollinators and predators. Although most vascular plant species are photosynthetic, some species are saprophytes or parasites, and do not manufacture their own food. Non-photosynthetic vascular plant species, such as fringed pinesap and coralroot orchid, are characterized by complex, symbiotic relationships involving both FEIS Volume 3, Chapter 3, part 4.6 – page 1 – Affected Environment and Environmental Consequences Sierra Nevada Forest Plan Amendment – Part 4.6 fungi and photosynthetic vascular plants (Furman and Trappe 1971, Wells 1981). Some of these saprophytes may play vital roles, along with fungi and bacteria, in decomposition of organic matter. In addition to their vital role in maintaining a functioning ecosystem, vascular plants provide commercial resources, including timber, forage, and other forest products. 4.6.2. Bryophytes, lichens, and fungi Shevock (1996) addressed the status of rare and endemic lichens and nonvascular plants for the Sierra Nevada Ecosystem Project (SNEP). Shevock considered 8 lichen species and 17 mosses as rare in the Sierra Nevada. He did not attempt to assess liverworts or fungi. There is a great need for systematic collecting and taxonomic study of Sierra Nevada bryophytes, lichens and fungi. Besides the small number of specimens available for study, there are currently few botanists trained to study these organisms. The importance of these groups to ecosystem function has been overlooked, and is beginning to receive increased attention by scientists and researchers. 4.6.2.1. Bryophytes Bryophytes are the nonvascular green plants, comprising mosses, liverworts, and hornworts. In contrast to the vascular plants, these plants have poorly developed conducting systems for water and food, and depend on water for reproduction (Vitt and others 1988). Bryophytes are usually low- growing plants found in damp or moist habitats, although some are adapted to dry habitats and a few are aquatic (Pritchard and Bradt 1984). During dry periods mosses can go dormant. When they are dormant, they are dehydrated and respiring at an extremely low rate. At higher elevations of the Sierra Nevada, in meadows and along streambanks, mosses may be the dominant vegetation. Many moss species have crucial roles in the hydrologic cycle and in the ecology of meadows and riparian areas. There are approximately 23,000 species of bryophytes worldwide, more than 1,220 of which have been documented in North America (Shevock 1996). No comprehensive moss flora exists for California, let alone the Sierra Nevada. However, a publication will soon be available entitled: Contributions toward a bryoflora of California I: A specimen-based catalogue of mosses and a key to species (Shevock, pers. comm. 2000). As of 1996, when the SNEP Report was completed, there were 508 moss species recorded in California, 116 species of liverworts, and 8 species of hornworts (Mishler 1995). Although the extent of bryophyte species diversity in the Sierra Nevada has not been thoroughly studied, compared to the Pacific Northwest, species diversity in the more xeric (drier) Sierra Nevada is expected to be relatively low. Bryophyte species tend to be more widely distributed than vascular plant species. However, within a broad overall range, they may occur in very localized patterns in ecologically specific habitats. Of the 17 mosses considered rare in the Sierra Nevada, 4 were placed on the Forest Service Pacific Southwest Region sensitive plant list in 1998. One of them, Orthotrichium spjutii, is endemic to the Sierra Nevada, known only from a single rock face next to a waterfall in the Walker River drainage. The other three species, Bruchia bolanderi, Meesia triquetra, and Meesia uliginosa, have ranges beyond California, but appear to be very rare in the Sierra Nevada. These species all occur in meadows; they are analyzed as members of the riparian guild in the TES plant section below. Bog and fen habitats within Sierra Nevada mountain meadows are often inhabited by mosses in the genus Sphagnum. There are about 17 species of Sphagnum in California. Sphagnum moss is FEIS Volume 3, Chapter 3, part 4.6 – page 2 – Affected Environment and Environmental Consequences Sierra Nevada Forest Plan Amendment – Part 4.6 immensely important ecologically. The presence of Sphagnum tends to indicate acidic conditions, since Sphagnum prefers to grow in acidic areas, and contributes to the acidity by giving off hydrogen ions. Sphagnum has the unique ability to perpetuate the acidic environment that it needs in this manner. Sphagnum has the ability to absorb more than 90 percent of its dry weight in water, because of the unique structure and arrangement of the leaf cells. Because of this, Sphagnum can be crucial in maintaining hydrological conditions in meadows, bogs, and fens. Mosses differ from vascular plants in several important ways with regard to impacts from ground- disturbing activities. Mosses have no root system, instead they are anchored by filamentous root-like structures (rhizoids). They take in any water that touches any part of the plant body. These closely compacted rhizoids can take up water very efficiently from the ground surface, but not below ground. When mosses are trampled by cattle or experience foot or vehicle traffic, they can not spring back from an underground root system the way vascular plants can. Another way mosses differ from vascular plants is in their response to water temperature. Mosses in Sierra Nevada mountain meadows can photosynthesize effectively at temperatures as low as 33 degrees F, in comparison to a lower limit of about 50 degrees F for vascular plants. Mosses cease photosynthesizing effectively at an upper limit of about 77 degrees F (in contrast to vascular plants, some of which can photosynthesize at temperatures of up to 100 degrees F). Above about 77 degrees F, mosses are respiring more rapidly than they are photosynthesizing, meaning that they are using food faster than they are manufacturing it. When the meadow sod is churned up by hooves or wheels, this may disrupt the upwellings of cold water, resulting in higher water temperatures (pers. comm. Norris 2000) Sierra Nevada botanists are beginning to survey for bryophytes during floristic surveys for projects, both to search for the sensitive mosses and to establish baseline data on moss distribution and ecology in Sierra Nevada national forests. Over the next few years, the ability to evaluate the effects of projects on the bryophyte flora should improve as our understanding of these previously overlooked species increases. 4.6.2.2. Lichens Lichens are a unique combination of two different types of organisms, fungus and alga, growing together in a symbiotic relationship. The fungal species captures and hosts microscopic green algae, and becomes a new “plant” body that functions as one organism. The algal cells photosynthesize and produce food that is absorbed by the fungus, which provides the “housing” for the algal cells (Hale and Cole 1988).