Project at a Glance

Title: Vegetation process studies : a progress report to the California Air Resources Board integrated watershed study

Principal Investigator / Author(s): Rundel, Philip W

Contractor: Laboratory of Biomedical and Environmental Sciences, UCLA

Contract Number: A4-121-32

Research Program Area: Ecosystem & Multimedia Effects

Topic Areas: Acid Deposition, Ecosystem Impacts


This final contract report describes research and field investigations undertaken to supply baseline data about ecosystem processes in the Emerald Lake basin which could potentially be impacted by acid deposition and air pollution. This is the second contract report covering a continuing project, over a five-year period. The first report covered the period from May 24, 1984 to August 23, 1985. This report covers field work for the period from July 1985 through 1987. A third final report, prepared later in 1988, will cover data collected during the 1987 field season, and will integrate the data from all five years of study into an overall framework. A more detailed discussion of the full data set will be made in that report. The investigations included in this report cover four areas--below-ground processes, above-ground processes, forest trees in the Emerald Lake basin, and floristics and vegetation structure. Below-ground biomass, phenology of growth, and productivity have been estimated for a variety of shrub and community-types based on data from both the 1985 and 1986 field seasons at Emerald Lake. Data are presented for willow thicket (Salix), chinquapin (Chrysolepis) shrub, mountain heather (Phyllodoce) and wet meadow communities. Above-ground biomass and productivity are presented for the same four communities, and compared in biomass to the below-ground data. The greatest above-ground biomass occurred in stands of Chrysolepis, but Phyllodoce mats had slightly higher rates of net primary production per unit area. Litter biomass is much greater in the Chrysolepis stands than in any other community studied. Pinus monticola (western white pine) is the dominant forest tree in the Emerald Lake basin. It comprises more than 70% of the 1206 trees censused in the basin. Pinus contorta ssp. murrayana (lodgepole pine) is second in importance with 17% of the trees, and P-balfouriana (fox-tail pine) third with 9.5%. Tree species are unevenly distributed throughout the basin, with P-monticola most abundant on the mesic bench and southwest-facing ridge, P-contorta ssp. murrayana dominant around the lake itself, and P-balfouriana largely restricted to the north-facing ridge on the western margin of the basin. The vascular plant flora of the Emerald Lake basin now includes 204 species, distributed in 132 genera and 41 families. Herbaceous perennials comprise nearly 80% of these species. Eight plant community types are present in the basin. These are dry forest, willow thicket, wet meadow, dry meadow, wet rock crevice, dry rock crevice, col luvi urn, and fell field communities.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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