TREE STEM GROWTH RING ANALYSIS—A CASE STUDY INVOLVING A MATURE CEDAR AND HOUSING DEVELOPMENT

Abstract

Summary Increment core samples taken from the main stem of cedar tree (Cedrus sp) showed unusual ring width sequences that could not be explained from detailed microscopic analysis. A full trunk disc was obtained and the ring patterns investigated. The occurrence of false and locally absent rings was determined and the rings dated. The beginning of the unusual ring width sequences coincided with development of the land around the trees for housing in the late 1970s. Root damage and/or changes in the rhizosphere associated with the housing development are likely to have been responsible for the period of abnormally slow and erratic growth of the tree. Despite a near twenty-year period of slow and erratic growth the tree had returned to a reasonable, consistent and regular growth ring width sequence by the late 1990s. Caution should be exercised when undertaking ring counts and interpreting ring widths using increment core samples taken from trees that may have suffered traumas as a result of root or soil damage or from the trunks of trees directly below large pruning wounds or lost branches. Similar caution should be exercised when interpreting increment core samples showing unusual resin ducts (cedars and some other conifers) or erratic ring widths.