Trees stressed by artificial and natural means were sampled for response in growth and vigor, carbohydrate content, resin pressure characteristics, and water relations. Tree response was found to reflect both the severity and type of stress imposed. Crown color and appearance were reliable indicators of prolonged stress and advanced decline...
The spruce weevil (Pissodes strobi) is a serious pest of Sitka spruce in Oregon. Weevils cause damage by killing the leader of a tree, resulting in defects such as crooks and forks that can render the tree unmerchantable. In this study, spruce stands 16-25 years old were surveyed for weevil...
Western white pine historically dominated northern Idaho’s forested landscape and was the Inland Empire’s most economically important tree. White pine blister rust, caused by the exotic fungus Cronartium ribicola, played a principal role in the decline of western white pine. The pathogen causes branch and bole cankers, which usually girdle...
Infestations of the western pine shoot borer (Eucosma sonomana Kearfott) in young stands of ponderosa pine (Pinusponderosa Lawson), were surveyed on the Deschutes National Forest. Elevation, slope, aspect, tree height, tree diameter, number of shoots in the terminal whorl, stand density, stand age and plant association for each stand were...
Ponderosa pine is an important species both commercially and ecologically in western North America. This study considers the incidence of insect and disease pests on a series of replicated ponderosa pine research plantations in northern California. The studies, on an environmental gradient, contain a series of silvicultural treatments including vegetation...
Delayed tree mortality is an unpredictable occurrence when prescribed burning is implemented. Fire scorched trees may die as the result of crown scorching, stem charring, root injury, bark beetle attack, or through a combination of these factors. This study examined ponderosa pine mortality and the incidence of two bark beetle...