SUSTAINABLE MANAGEMENT PRACTICES OF UNDER STORY “BRUSH” SPECIES IN SOUTHERN COASTAL OREGON
Document Type Thesis or dissertation
Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Master of Environmental Studies 2007.
The coastal forests of Oregon are among the most biologically productive regions in the world. This high level of forest productivity enabled a large timber industry to grow in the region, and supply the area with its economic and cultural base. The economy experienced a crisis during the 1980s when the logging industry began closing down mills and laying people off. One factor which contributed to the loss of jobs was the loss of old growth trees due to decades of harvesting. As loggers tried to harvest the remaining old growth trees, environmentalist organized and successfully slowed down, or halted their efforts. While the attitudes of the past may have been one of either jobs or the environments, today there are many who are trying to find a balance and integrate the two through a sustainable forest management philosophy known as eco-forestry. Two challenges to this practice are how to sustainably suppress competitive under story “brush” species, and how to manage riparian zones. This capstone addresses both of these issues. The past and present uses of brush species including, the floral and nursery industry, as food for agricultural animals, medicinal and aboriginal uses are reviewed. A survey for economic brush species in riparian zones under different forestry management practices is discussed.
The findings indicate that the eco-forested site had a higher number of economic brush species then sites under different management practices, including preserved sites. The logging site which had trees harvested in its riparian zone had a different assemblage of species then either other logging or preserved sites. There was no correlation between the ground coverage of one brush species to another, but a decrease in the ground coverage of Rubus species may lead to an increase in overall biodiversity. Stream bank instability was found to be greatest in sites of industrial logging. The eco-forested sites conversely had the most stable stream banks of any site. How to manage riparian zones for economic brush species and the need for a program which certifies small, independent, sustainable, no-climax based, forestry practices are discussed.
Date Posted: 23 July 2007