Biomass inventory and regrowth rate of harvestable tree and shrub moss in the Oregon Coast Range

Abstract

The commercial moss harvest industry is at a crossroads. Concerns about the sustainability of harvest have led to moratoria on moss harvest from public lands, limiting access to this nontimber forest resource in most of the highest production regions of the United States. Resumption of legal harvest depends on improved knowledge about resource inventory and yield, which will enable the development of appropriate management scenarios. We present here the results of an inventory of current readily available legally harvestable moss and of a 10-year biomass regrowth study from the Coast Range of western Oregon. Harvestable tree and shrub moss was removed from 21 sites on the Siuslaw National Forest, using typical harvest methods and following the Forest's standards and guidelines for commercial moss harvest. Biomass across these sites averaged only 19 kg/ha (fresh weight). Only 52% of sites bore any harvestable moss, and only 38% had commercial quantities. Moss mats regrowing on experimentally stripped vine maple (Acer circinatum) shrub stems accumulated mass at a mean rate of 3.0 g/m-stem/year across six sites. At this rate, moss mats of equivalent biomass to the originally harvested mats would require approximately 27 years to develop. These data provide estimates of input parameters needed to develop schedules for commercial moss harvest. Copyright © 2008 by the Society of American Foresters.