The Pygmy Forest Region of Northern California: Studies on Biomass and Primary Productivity

A most striking effect of soil on vegetation occurs on the coastal terraces of Mendocino County, northern California (longitude 123? 50' W, latitude 39? 20' N). Giant forests of the coastal redwood (Sequoia sempervirenst), 60-100 m tall, occur on slopes, in ravines and on alluvial bottoms, while 'pygmy forests' of two endemic conifers (Cupressus pygmaea and Pinus contorta ssp. bolanderi), 1-2 m tall, occur on level, intensely podzolized soils of terrace flats. These extreme communities are connected by forests of intermediate stature; in particular Bishop pines (P. muricata) in stands 15-30 m tall are dominant on terrace foredunes and on the richer soils of the terraces. The vegetation of this coastal strip has been characterized in relation to a gradient of soil nutrients, and other habitat features, in an earlier paper (Westman 1975). This article presents measurements of the biomass, productivity and surface areas in the pygmy conifer forests and compares these results with estimates for forests of Sequoia sempervirens, Pinus muricata, and other species.