This database contains data about the trees, and the tree-ring records collected from them, in a 3.3 hectare plot in an old-growth Douglas-fir/western hemlock stand in the western Cascade Range of southern Washington. The trees were mapped before harvest. After harvest, samples were collected from their stumps, and in some cases, their felled boles. The samples were taken back to the lab where they were prepared, crossdated, and evaluated for the data contained in this database. See references cited below for details about the stand and the collection, preparation and evaluation of samples (Winter et al. 2002a,b; Winter 2000). The data were originally entered into the database program Paradox as multiple files linked by the attributes "Tag", "Height" and "Sample". For the purposes of the present, general- use database, these Paradox files were copied to the text files found here. The present database consists of this document (Winter.doc), an Excel file describing the database's 9 entities and their attributes (Winter.xls), and 9 text files (*.txt) containing the data for the respective entities. In these entities, data about the trees includes: identity (tag number), species, dbh and mapped co- ordinates. Data about the tree-ring samples collected from these trees includes: identity of tree that the sample was collected from, tree-height (as if tree were standing) of collection, and various data about physical aspects of the sample. Data evaluated from the prepared, crossdated tree-ring samples includes: dates of centers, various data about "growth-changes" (abrupt and sustained changes in ringwidths), data relevant to Douglas-fir crown development, radial growth measurements, and data relevant to height- growth of Douglas-fir in the study stand. Note that some data may be repeated in multiple entities, for purposes of linking together data from different entities, and for purposes of the original study for which the database was developed.
Donald Q. DeWitt, Eric A. Miller, Jerry F. Franklin, Linda B. Brubaker, Linda Ellen Winter
This database was developed as part of a study that used tree-ring records to reconstruct the structural development of an old-growth Douglas-fir/western hemlock stand in the western Cascade Range of southern Washington (Winter 2000; Winter et al. 2002a,b). A major purpose of this study was to provide information that might be useful where management policies emphasize the development of old- growth structures. At the time of the study, decades of logging in the Pacific Northwest had transformed once extensive tracts of old-growth Douglas- fir/western hemlock forests to landscapes dominated by younger forests intermixed with scattered remnants of old stands. This conversion from old to young forests caused widespread changes in habitats, in the abundance of many terrestrial and aquatic species, and in a variety of ecological functions such as nutrient and water cycling. The ecological, social and economic consequences of this large-scale forest transformation generated intense controversy, leading to management policies with increased emphasis on maintaining and developing old-growth ecosystems across the current and future landscapes of the Pacific Northwest. It was in this context that the study, with this database, developed.