During the past decade (1978-87), breeding success and
productivity of bald eagles on the lower Columbia River (LCR) has
been far below state and regional averages and well below levels
required for delisting under the Endangered Species Act by the
Pacific States Bald Eagle Recovery Plan. Human disturbance was
suspected...
Human-induced fragmentation of forests is increasing, yet the consequences of these landscape changes to vertebrate communities are poorly understood. Despite progress in our understanding of how bird communities
respond to forest fragmentation caused by agricultural or urban development, we have little understanding of these dynamics in landscapes undergoing intensive forest...
I analyzed the relationship between avian abundance and landscape structure at five spatial resolutions for 30 subbasins in the central Oregon Coast Range using remotely sensed data and a geographic information system (GIS). I developed maps of forest successional stages from Landsat Thematic Mapper (TM) data at a spatial resolution...
Species distribution models (SDMs) are currently being used to identify essential fish habitat and guide
fisheries management worldwide. We present SDMs based on generalized linear mixed models (GLMM) of
the fall distribution or occurrence of juvenile American shad (Alosa sapidissima) and juvenile striped bass
(Morone saxatilis) in the Hudson River...
Forest managers are challenged to restore resilience to forests with an elevated risk of stand-replacing fire by using mechanical thinning and prescribed fire. Implementation of these methods can be constrained by mandates to conserve sensitive wildlife species like the Pacific marten (Martes caurina). Martens avoid simplified forest stands created by...
The distribution of American martens (Martes americana) within Sagehen Creek Experimental Forest (SCEF), Tahoe National Forest, California has been periodically documented from 1980–1993. This area has been the location of nine marten surveys, each involving a systematic detection/nondetection survey on the same grid. These data are an unprecedented time series...
Black bears (Ursus americanus) in western Oregon and Washington peel bark from conifers in early spring to forage on the sugar-rich phloem and cambial tissues. This provides important energy at a time when similarly attractive forage is scarce. Bears often damage Douglas-fir (Pseudotsuga menziesii) trees in stands that are intensively...
Forests in the western United States have changed drastically over the past 150 years given a long history of utilization (harvest and grazing) and associated fire exclusion. These actions have altered the composition and structure of these forests as well as affected ecosystem function. Current policies for federal land management...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...
History is an invaluable source of information to understand and evaluate management influences on contemporary ecosystems and landscapes. The first two chapters (Chapters 2 and 3) explored the concept of historical range of variability (HRV) in landscape structure and stand structure using a stochastic fire simulation model to simulate presettlement...