Demography of ancient western juniper (Juniperus occidentalis var. occidentalis) trees on Horse Ridge in central Oregon, USA

This data publication contains a dataset of dendrochronologically crossdated western juniper (Juniperus occidentalis var. occidentalis) tree recruitment dates sampled from a grid of 21 plots distributed over 130 hectares on Horse Ridge in central Oregon, USA. Samples were collected in May 2010. The trees recruited between 845 and 1961 CE, but most trees established after the mid 1550s. Data include establishment date information for all trees within the plots that were at least 10 centimeters (cm) in diameter at 30 cm height from the modern ground surface; tallies of unsampled trees within the plots, in other words those that were at least 30 cm in height, but less than 10 cm in diameter; geophysical and plant community plot characteristics; and understory species presence. Also included are four photographs of each plot and one or more photographs of each sampled tree.We sampled this ancient juniper woodland to infer the drivers of tree recruitment.All of the wood samples we collected are permanently archived and available for further study as part of the LTRR Collection at the Laboratory of Tree-Ring Research (LTRR), University of Arizona (Bryant Bannister Tree-Ring Building, 1215 E. Lowell Street, Tucson, AZ 85721-0045, USA): https://ltrr.arizona.edu/. These data were originally published on 04/04/2022. Minor metadata updates were made on 04/25/2023 and 01/17/2025. For more information about this study and these data, see Loehman et al. (2022).