Sapwood estimates in the interpretation of tree-ring dates

Many timber finds lack some or all of the outer, sapwood rings formed in the years just before felling. In order to estimate felling date once the outermost remaining ring has been dated, it is necessary to estimate the number of sapwood rings originally present. Methods doing this for oak are reviewed in the light of an intensive study of living trees at one site and an extensive study of 175 samples from living trees in North Wales and northwest England. Some methods reported in the literature are found to be invalid. A method reported by Hollstein (1965) is most reliable, with modifications for known variations in sapwood number with position in the tree. At present the best available estimate is that a value of 30 sapwood rings be used (95% confidence limits: 19–50).     

THE DECLINE OF CALIFORNIA'S NORTH COAST REDWOOD REGION

The Redwood Timber Region of Northern California has experienced a gradual decline in its natural resource base combined with intensified struggles over preservation and conservation. This region is used as a case study for examining the historic pattern of resource decline, the ambiguous roles of environmentalist pressure, the failure of public regulation, and a range of regional responses to economic decline. In this case, more intense forest management techniques (herbicides, fertilizer, thinning), more public investment in timber regeneration programs, and the emergence of an underground economy in marijuana growing are core elements of the response to resource decline. Theoretical, political, and environmental problems with these approaches are examined.     

SQUARE PEGS IN ROUND HOLES: PROGRAM EVALUATION AND ORGANIZATIONAL UNCERTAINTY

It is argued that variation in uncertainty about social program goals and causal processes should influence the selection of evaluation designs and methods. Eighteen prominent evaluation reports are examined to contrast predicted evaluation strategies derived from theory about organizational uncertainty with the actual evaluation methods used. It was found that the actual design, measurement, and analysis procedures were frequently different from procedures that were compatible with the kinds of program uncertainty described in the evaluation reports. It is suggested that theory and practice in program evaluation can be improved by systematically incorporating organizational concepts that would contribute to the selection of evaluation methods.