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Tree mortality in western conifer forests is a complex process involving several related factors. Conifer mortality tends to be more common in high-elevation forests where stress from weather, insects, and disease result in higher rates of mortality and in the drier interior forests where mortality from fire, insects, and disease are common. Immediate mortality from fire damage may be obvious, but currently there is considerable controversy about labeling fire-injured green trees as dead that have a high probability of experiencing delayed mortality. Trees die when carbohydrates used in respiration exceed those produced in photosynthesis or water movement is impaired, the tree desiccates, and photosynthesis ceases. Immediate or delayed tree mortality may be directly due to biotic or abiotic causes and may be affected by previous damage, current condition (vigor), and attack by secondary agents such as bark beetles. A particular pathogen or insect usually attacks, damages, or kills only one portion of a tree. Trees that are damaged or attacked by pests and expected to have a dead or nonfunctional root system or a nonfunctional stem within 5 years may be considered either dead or death is imminent. Numerous studies have produced logistic regression equations or other statistical models to help determine probability of tree survival. We define and propose that a “dead tree” designation is justified for most species when at least three of the four quadrants from around the base of the root collar has cambium, inner bark, or phloem that are discolored and dead. For large ponderosa pines, a dead tree has all four quadrants with dead cambium.

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This is a documentary study of the origin and investigation of all criminal prosecutions of collusive trade agreements filed by the Antitrust Division, US. Department of Justice from 1946 through 1970. The methodology seeks to reconstruct these cases from previously classified investigative files of the division. Observations include the sources of organizational intelligence, investigative methods, and encounters among antitrust victims, offenders, and officials. Most cases originate with complainants and informants outside the agency, but most evidence is obtained with the cooperation of offenders, who usually receive immunity or leniency in return. The conclusions suggest that public exposure of trade conspiracies serves as a deterrent despite weak penalties.