The hump-shaped relationship that predicts highest species richness (species/unit area) at intermediate levels of productivity was examined for woody plants across the Pacific and Inland Northwest of the U.S. Many studies have examined this relationship at regional scales, but commonly use species range maps and surrogate measures of productivity (e.g....
This publication is a reference guide for forest soils productivity and management. Main topics include (1) understanding and managing risk, (2) soil characteristics that affect productivity, (3) soil survey information for forestland managers/management of soil erosion, (4) managing mass wasting risk, (5) managing soil disturbance, and (6) maintaining adequate nutrient...
Based on the premise that interfirm comparison can be an effective
productivity improvement tool, productivity interfirm comparison (PIC)
methods are examined in this research. The first part is an extensive
literature review regarding the conventional interfirm comparison (IFC)
scheme accepted widely in many countries outside the United States.
The cards in this guide are designed to help
you quickly learn the main groups of natural
enemies of crop and garden pests, their
predacious activity, and tips for observing them.
Photographs are of the most common species in
the Pacific Northwest.
Hemlock woolly adelgid, Adelges tsugae Annand, is a destructive introduced pest of hemlock trees in eastern North America, and management has focused on the use of natural enemies through classical biological control. Two species of chamaemyiid flies, Leucopis argenticollis Zetterstedt and Leucopis atrifacies (Aldrich) have been collected previously from western...
The predatory mite Typhlodromus pyri (Acari: Phytoseiidae) is the predominant
species in cool climate Pacific Northwest vineyards and a principal predator of pest mites
including the grapevine rust mite Calepitrimerus vitis (Acari: Eriophyidae). In recent
years vineyards have been experiencing C. vitis population outbreaks leading to increased
economic damage from...
The hemlock woolly adelgid, Adelges tsugae, is causing widespread mortality of eastern hemlock, Tsuga canadensis, in the eastern United States. In the West, A. tsugae causes negligible damage to western hemlock, Tsuga heterophylla. Host tolerance traits and presence of endemic predators may be contributing to the relative tolerance of western...
Management practices following forest harvest can affect long-term soil productivity through alteration of soil carbon (C) and nitrogen (N) pools, but processes contributing to change are poorly understood. I assessed effects of three levels of logging-debris retention in combination with initial or annual applications of competing vegetation control (CVC) following...
The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a
worldwide pest of numerous agronomic and horticultural plants. Conservation
biological control of this pest can be unreliable due to asynchrony of natural enemies
and certain horticultural practices that have a direct or indirect affect on natural
enemies and the...