Forest harvest patterns on private land in western Oregon from 1972 to 2002

Graduation date: 2006This project examined the harvest patterns found on private forestland in western Oregon (46000 1cm2) between 1972 and 2002. The research addressed hypotheses concerning the behaviors of different classes of owners as defined by total amount of forestland owned. Existing forest stand disturbance data and ownership data were combined using GIS and the Fragstats program to determine the numbers of harvest patches and percentage of harvest in 250 individual forested parcels ranging from 40 to 110000 km2, for each of seven 3 to 6 year time intervals in the study period. Trends over time and spatial patterns of harvest by owner were assessed using maps and graphs. Private industrial forest owners as a group harvested at more rapid rate and created more patches than private non-industrial forest owners in western Oregon over the period 1972-2002. Private industrial owners did not differ in the numbers of patches created or the rates of harvest over the entire study period of 1972 to 2002, but small private industrial owners (less than 10,000 hectares), harvested at a significantly more rapid rate than other private industrial classes during the 1988 to 1991 time period. The number of patches created from 1972 to 2002 was significantly positively related to the area of the parcel but not related to the percentage of the parcel that was harvested from 1972 to 2002. Forest harvest rates increased when timber prices increased in the late 1980s, but did not respond to even higher timber prices in the early 1990s. Controlling for forest owner type and size, forest harvest on private lands was significantly lower and fewer patches were created in the Klamath Mountains province compared to the Oregon Coast Range and the western Cascades. Parcels in the margin of the Willamette Valley were 1.58 times more likely than other portions of western Oregon to have been harvested at rates exceeding 10% per year over some portion of the study period. These results generally indicate that private industrial owners have a range of behaviors that are partially explained by owner objectives (industrial vs. non-industrial) and size of landholdings. Based on these findings, predictions about future landscape patterns should take into account differences in objectives within the private industrial class of landowners. In particular, in western Oregon small private forest owners were quite sensitive to timber prices and uncertainty in public forest management policy in the late 1980s, whereas other private industry owners maintained fairly steady rates of harvest, and most private non-industrial owners refrained from harvest, over the 1972-2002 period