Putting the stewardship concept into practice: Commercial moss harvest in Northwestern Oregon, USA

Abstract

Increased demand for non-timber forest products has spurred increased regulation of these resources as well as recognition of the need to include harvesters in monitoring efforts. The moss harvest monitoring program on the Siuslaw National Forest in the Pacific Northwest included a pilot stewardship program involving two 5-year leases of 890 ha parcels of mixed conifer- Alnus forest to a local commercial moss harvester under the condition that the harvester adhere to specific harvest guidelines and provide data on how much moss was removed. Across both lease areas, nearly 66,000 kg of tree-moss was harvested over a 48-month period, mostly during the dry summer season. The program provided for direct harvester participation, made the product available on a year-round basis, and improved patrol of illegal harvest in the lease area. In addition, three experiments were conducted to contrast moss abundance, species richness, and species composition using four levels of harvest intensity (Control in which harvest was prohibited, Low Intensity harvest approximating current standards and guidelines = ca. 34 kg/ha, High Intensity harvest approximating unregulated harvest levels = ca. 112 kg/ha, and “No Rules” harvest with no restrictions of any kind). Subsampling data indicated that cover on vine maple shrubs immediately following harvest was reduced by 5% and 16–20% for Low Intensity and High Intensity harvest treatments, respectively. These treatment differences remained for two years in riparian areas but were non-significant after one year in upland mixed forest. Species richness did not vary among harvest intensities and impacts to species composition, which were generally restricted to stems actually harvested, dissipated after one or two years. Because impacts restricted to harvested stems averaged out at the plot-level, plot-level surveys were less sensitive to harvest impacts than host-level subsampling. Due to the slow rate of recovery of this resource, future Stewardship Areas for moss harvest may be impractical, but this approach may be a viable option for non-timber forest products with shorter rotations.