There is a significant dendrochronological gap in the Puna of the central Andes of Peru, which motivates research on new species. In this study, we present the first tree-ring chronologies of Escallonia myrtilloides. We collected samples at San Pedro Saño and Sapallanga in Peru, analyzed the anatomical characteristics that delimit the annual growth rings, and developed two tree-ring chronologies through conventional dendrochronological techniques. The tree-ring chronologies cover the period 1940–2015 (76 years) for San Pedro Saño and 1960–2015 (56 years) for Sapallanga. The E. myrtilloides chronologies presented similar values of mean sensitivity, Rbar and EPS to those recorded for Polylepis tarapacana, Polylepis pepei, and Polylepis rugulosa in the Puna region. The analysis of the climate-growth relationships indicated positive correlations with precipitation and negative correlations with temperature in particular months of the current growing season (October–April). This precipitation/temperature-sensitive record highlights the high value of E. myrtilloides for future studies on the influence of climate on tree growth in the central Andes.

New oak tree-ring chronologies for European Russia built with subfossil oak wood excavated from the alluvial deposits of the Zapadnaya Dvina (Daugava) River and archaeological samples from Novgorod and Vyazma are presented. They have been matched with the nearest absolutely dated tree-ring chronology constructed in Polotsk (Republic of Belarus) and dated to the periods AD 649–1382 (Zapadnaya Dvina), AD 1059–1386 (Novgorod), and AD 1074–1306 (Vyazma). Dates have been further confirmed via comparison with subfossil oaks from Smarhon (Republic of Belarus) and Baltic 1 chronology as well as by radiocarbon dating. Newly built medieval chronologies can be used for dating and provenancing of oak wood originating from archaeological sites and natural archives.

Drought in the North American Southwest is a recurring phenomenon. The knowledge of drought recurrence and severity is crucial for sustainable water resource management in the region. Tree-ring reconstructions of climate variables provide valuable indirect evidence of climate variability and elucidate the relationship between large-scale circulation anomalies and the climate in the region. Here we have developed a May–July Palmer Drought Severity Index (PDSI) reconstruction from tree-ring chronologies of Pseudotsuga menziesii from the Chiricahua Mountains (southeastern Arizona) for the period 1634–2017 CE. The driest period occurred at the beginning of the 21^st Century (2000–2005), followed by 1666–1670, 1952–1956, and 1729–1734. Reconstructed PDSI of the Chiricahua Mountains shows a weak correlation with the El Niño-Southern Oscillation, with intermittent influence as previous studies have reported. The Pacific Decadal Oscillation accounts for the majority of the variability in the Chiricahua hydroclimate, except for the period from 1860–1950 when the predominant driver was the North Atlantic Oscillation.

As the use of the increment borer is supposed to be invasive, there is a question of how coring affects subsequent growth or the health of various tree species. Ten Picea abies (L.) Karst. trees in the Beskydy Mts. (Czech Republic) were analysed nine years after coring by an increment borer (June 2011) to determine their anatomical and growth responses to the coring. Cores (13 per tree) were extracted at regular vertical and horizontal distances to evaluate the spatio-temporal pattern of the responses. Sixty percent of trees reacted to the increment boring by creating a vertical crack at the end of year 2011. Traumatic Resin Ducts (TRDs) appeared in all trees relatively soon after coring, with a predominance in the vertical axis. In the horizontal axis, TRDs gradually disappeared with increasing distance from the old coring hole. Overall the spatio-temporal occurrence of TRDs varied in the tree trunk. The immediacy of the response was indirectly dependent on the distance from the 2011 core. Trees responded by growth release the following year after coring as well. The duration of growth disturbances reached three years on average. The results show that P. abies trees are not critically endangered by increment borer coring.

High quality specimen digitization is becoming standard across the sciences, is relevant for curation of natural history collections, and must become a priority for dendrochronology. This paper overviews the enduring role of imaging in dendrochronology, summarizes the potential relevance of gigapixel macro photography of polished specimens, offers a long-term review of a commercial imaging system, and reports our progress imaging entire collections of specimens at ultra-high resolution. Our gigapixel images of polished specimens have proven effective for digital analyses, archiving, and education, and we believe macro photography may prove a lower cost and more broadly accessible digitization alternative to microtomy and X-rays. We advocate for gigapixel macro photography as one accessible and adaptable paradigm to elevate reflected light imaging standards in dendrochronology.