Influence of wood harvest on tree-ring time-series of Picea abies in a temperate forest

Tree-ring width data are the prime source of high-resolution climate reconstructions covering recent millennia. Their variations, from year-to-year, are calibrated against regional instrumental data to evaluate the strength of associations with temperature and precipitation records, though the level of variance explained by climatic variables is frequently less than 50%. Among the remaining factors affecting tree growth, the influence of forest management for tree-ring width time-series used to resolve annual climate reconstructions remains relatively unexplored. We here evaluate the impact of conventional single-tree harvesting on tree-ring data using a compilation of circumstantially mapped Picea abies sites in western Germany. Climate signals are explored by calibration against regional temperature and precipitation data, and the influences of forest management analyzed using long-term logging data spanning the past 40–80 years and mapped stumps (and neighboring trees) spanning the past 20 years. Our results indicate a weak but statistically significant control of total May–July precipitation of P. abies growth. This association is only marginally, if at all, affected by forest management, i.e. wider tree-rings due to improved access to light and nutrients in years after logging events are either not found or in line with increased precipitation sums following single-tree harvest. These findings suggest only minor influences of selective harvesting on Picea tree-ring growth in western Germany, and overall limited biases of annually resolved climate reconstructions from lower elevation central European sites due to historical logging events.

► 300 core samples from three circumstantially mapped Picea abies sites are analyzed.
► Tree-ring width time-series contain a May–July precipitation signal.
► Single-tree harvest has only minor impact on tree-ring width time-series.
► Trees in distances <5 m to stumps show post-logging growth releases.
► P. abies climate signals remain undisturbed from logging event.