Abstract
The microclimatic conditions within forests have great importance for biodiversity and ecosystem functioning. Consequently, understanding how management and associated changes in forest structure drive the inter-annual variability in forest microclimates is critical to forecasting ecosystem responses to climate change. Here, we investigated the impact of the amount of harvested timber on the inter-annual variability of forest microclimates in different management systems in Germany. We combined an 11-year time-series of observations from meteorological stations at 149 permanent forest plots and 50 adjacent open land plots with stand structural and topographic variables, as well as annual data on timber harvest. A linear mixed-effects model, incorporating harvested basal area, basal area, diurnal temperature range anomaly in the open land, precipitation, and elevation above sea level, explained 72.48% of the variance in the diurnal temperature range anomaly in forests. Overall, we found only weak evidence for forest management effects on forest microclimate anomalies. Our results suggest that microclimate anomalies are predominantly driven by precipitation and temperatures outside the forests, with forest management effects being of comparably low importance. We conclude that management interventions with low to medium intensity do not counteract the maintenance of forest microclimates. As the inter-annual variability in the diurnal temperature is rather linked to inter-annual differences in weather conditions than to forest management, climate change-related weather extremes will most likely result in microclimate extremes within forests, potentially affecting their biodiversity and ecosystem functioning.