No detrimental long-term impacts of coring on tree growth ormortality across European forests

O_LITree cores are widely used across a broad range of disciplines in the environmental sciences, most notably as a tool to measure tree growth, estimate tree age, characterise wood anatomy and reconstruct past climate. However, because extracting tree cores is an invasive procedure, concerns about their use are often raised due to perceived risks for tree health. C_LIO_LIHere we comprehensively test the long-term impacts of tree coring on 16 European tree species using a dataset spanning the entire European continent. Over the course of a decade, we tracked the growth and survival of 3334 trees cored in 2012 (including trees cored once and twice) and compared them to that of a cohort of 7413 neighbouring trees that were never cored. C_LIO_LIWe found no evidence that coring had a detrimental impact on either the growth or survival of trees, irrespective of their size, species, climatic environmental or the number of times they were cored. However, we did observe a small positive stem increment response (2.0% for trees cored once and 6.2% for trees cored twice), which we hypothesise is most likely the result of vertical scarring from the coring wound, with potential consequences for the accuracy of repeated diameter measurements collected at the same height. C_LIO_LIOur study supports the use of tree coring as a low-impact method for characterising the growth, age and function of a wide range of tree species. However, to avoid biasing long-term forest census measurements, tree cores should always be collected well above or below the point of measurement of tree stem diameters. C_LI