Abstract
The International Tree-Ring Data Bank (ITRDB) was established in 1974 to serve as a permanent repository for basic tree-ring data (measurements, chronologies, and derived reconstructions) developed and contributed by scientists from around the world. Housed at the World Data Center-A (WDC-A) for Paleoclima tology at the National Geophysical Data Center in Boulder, Colorado, USA, the ITRDB currently contains 3275 tree-ring chronologies and 2804 tree-ring measurement data sets from over 1500 sites, contributed by 139 researchers worldwide. These data sets represent information from over 100 tree and shrub species. As part of the WDC system, the ITRDB makes its holdings freely available to all scientists. The ITRDB is administered by an international Advisory Committee consisting of eight dendrochronologists representing different subdisciplines in the tree-ring sciences. The ITRDB also provides two additional important services: the creation and management of the ITRDB Dendrochronology Forum on the Internet, and development and distribution of a collection of computer programs for tree-ring analyses known as the ITRDB Program Library. Future efforts of the ITRDB will focus on increasing the worldwide coverage of its database holdings, and to make the ITRDB a more visible component in the scientific community.