The potential use of pilgerodendron uviferum tree-ring dating in the historical interpretation of the churches of Chiloé, World Heritage

The churches on Chiloé Island are the oldest wood structures in Chile. Chiloé islanders adapted European colonial techniques and developed unique regional construction styles when building these UNESCO-recognized community and religious centers. Although these historical treasures are preserved, much of the construction history of these churches remains unknown. Tree-ring dating is a proven archeological dating method used to identify the logging dates of wood used for constructiong historical buildings. The majority of churches on Chiloé were constructed using Pilgerodendron uviferum (“ciprés de las Guaitecas”) wood. Therefore, the objective of this study was to evaluate the potential use of this species to date timber found at churches in Vilupulli and Ichuac. Timber sections from both structures were successfully cross-dated using three regional multi-century long P. uviferum tree-ring site chronologies located in the Chiloé region (two from the island and one from the nearby Andes region). Samples from pillars located in the tower of the Vilupulli church contained 311 and 181 tree-rings, respectively, while four samples from floor beams in the Ichuac church contained 79, 89, 97 and 135 annual growth. Timber used to build the Vilupulli church tower cross-dates to 1918 and corroborates colloquial knowledge that the structure was built in the early 20th century. Dates obtained from the floor beams in theIchuac church range from 1920 to1929, and contradict the colloquial thinking that the structure was built at the end of the 19th century, though these could represent material used in a later restoration not previously recorded in Ichuac’s local history. These findings confirm that P. uviferum presents strong capabilities for further use in tree ring dating of important historical structures located in the temperate region of Southern Chile.