Northwest Forest Plan, the first 10 years (1994-2003)
Subtitle: status and trends of populations and nesting habitat for the marbled murrelet
By: technical coordinators Mark H. Huff ... [et al.].
Contributors: Huff, Mark H.; Pacific Northwest Research Station (Portland, Or.)
Series: General technical report PNW -- GTR-650.; General technical report PNW -- 650.
Publisher: U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station
Published: 2006
Place of publication: Portland, Or
Language: eng
Number of pages: 149
Subjects: Northwest Forest Plan (U.S.); Marbled murrelet -- Northwest, Pacific.; Marbled murrelet -- Habitat -- Northwest, Pacific.
Other titles: Status and trends of populations and nesting habitat for the marbled murrelet.
Description: The Northwest Forest Plan (the Plan) is a large-scale ecosystem management plan for federal land in the Pacific Northwest. Marbled murrelet (Brachyramphus marmoratus) populations and habitat were monitored to evaluate effectiveness of the Plan. The chapters in this volume summarize information on marbled murrelet ecology and present the monitoring results for marbled murrelets over the first 10 years of the Plan, 1994 to 2003. The marbled murrelet was federally listed in 1992 as threatened in Washington, Oregon, and California. The Plan identified the marbled murrelet as a major objective in the Plan design and hence the status of the murrelet is a key indicator of the Plan's potential success. Effectiveness monitoring for the marbled murrelet has two facets: (1) assess population trends at sea by using a unified sampling design and standardized survey methods, and (2) establish a credible estimate of baseline nesting-habitat data by modeling habitat relations, and use the baseline to track habitat changes over time. Our primary monitoring objective was to determine the status and trends of marbled murrelet populations and nesting habitat in the Plan area. To estimate marbled murrelet population size, we sampled from boats by using line transects within 8 km of the Washington, Oregon, and northern California coastline, covering about 3,400 mi2. From 2000 to 2003, the largest population estimate was in Puget Sound and Strait of Juan de Fuca of Washington; the highest densities were along the coast of Oregon and California north of the Humboldt-Mendocino County line, and the smallest population and lowest density were from the Humboldt-Mendocino County line south about 200 mi to San Francisco Bay, California. Marbled murrelet population estimates did not change significantly over 4 years. We estimated that 15 or 9 total years of surveys will be needed to detect a 2 or 5 percent annual decrease, respectively, using a test threshold at 95 percent power. We used three modeling approaches to estimate the amount and distribution of baseline nesting habitat: expert judgment, ecological niche factor analysis, and logistic regression. Our logistic regression model predicted that murrelet nesting habitat is more likely at sites that are closer to the sea, are on relatively flat terrain, are topographically cooler, have relatively fewer conifers larger than pole size (>10 in diameter at breast height [d.b.h.]), have greater basal area of trees larger than pole size, and have greater basal area of larger diameter trees (>30 in d.b.h.). Estimates of amounts of baseline nesting habitat differed with modeling approaches, but all models showed that over 80 percent of baseline habitat on federally administered land occurred in reserved lands. A high proportion of baseline habitat occurred on nonfederal land; amounts of nonfederal habitat differed among provinces. Fire and harvest have led to losses of nesting habitat since the Plan was implemented, with higher rates of loss on nonfederal land. We estimated that only 13 percent of U.S. Forest Service and Bureau of Land Management land had an even chance or better of being suitable nesting habitat; meaning that, relative odds (odds ratios) were equal to or exceeded that of known occupied nesting habitat. We compare the efficacies of the different model approaches, discuss implications of our results for future monitoring, and propose that a comprehensive evaluation of the potential breeding range of marbled murrelet be done for federal land in the Plan area.
Notes: Cover title.

"June 2006."

Includes bibliographical references.

Also available via Internet.