Biomass, Productivity, and Nutrient Allocation in Subalpine Shrublands and Meadows of the Emerald Lake Basin, Sequoia National Park, California

Abstract

The Emerald Lake Basin provides a long-term site for research on hydrology, ecology, and biogeochemistry, as well as baseline data for a representative subalpine watershed in the Sierra Nevada of California. Field studies provided quantitative data on the biomass, net primary production, and nutrient allocation of major subalpine shrub and meadow communities. Measurements carried out over two growing seasons found aboveground biomass per unit canopy area was 3857 g m-2 in Chrysolepis sempervirens, 3360 g m-2 in Salix orestera, and 1614 g m-2 in Phyllodoce breweri. The biomass for Chrysolepis and Salix canopies were high compared to other published data for subalpine and alpine shrublands, but the Phyllodoce biomass was comparable to values for ericaceous heath in the Rocky Mountains and European Alps. Wet and dry meadows had 377 and 98 g m-2, respectively, in aboveground living tissues, comparable to values from the Rocky Mountains and European Alps. Belowground biomass for shrub communities was the highest for Phyllodoce (3670 g m-2), followed by Chrysolepis (2400 g m-2) and Salix (2070 g m-2). The wet meadow community had a surprisingly high belowground biomass of 2897 g m-2, reflecting the dominance of large perennial herb species. This resulted from a root:shoot ratio of 8.21 compared to 5.72 in the dry meadow community. Canopies of Chrysolepis and Salix had root:shoot ratios of 0.62 and 0.61, respectively, and Phyllodoce a ratio of 2.27.