Exploring the interplay of multi-scale climatic variables and forest thinning: From global models to microsite conditions in Northwestern Patagonia

Abstract

Understanding the interplay between global, regional, and local climatic patterns is critical for sustainable forest management in mixed forests. This research evaluates the influence of site conditions (altitude, slope, and exposure) on air temperature, relative humidity (RH), and vapor pressure deficit (VPD) across two distinct sites and four locations within these. Weather station registers were compared with regional estimates from the ERA5 global model. At two locations in one of these sites, microsite conditions were further analyzed under varying thinning intensities, using thermohygrometers. To explore daily cycles, a 24-hour band-pass filter using a Gabor wavelet was applied, calculating weighted averages, amplitudes, and phase shifts. Confidence intervals were derived through Monte Carlo simulations to facilitate robust comparisons across treatments and locations. Observations from weather stations revealed significant discrepancies with ERA5 model estimates, highlighting the limitations of the ERA5 model in capturing fine-scale microclimatic variability driven by local topography and vegetation cover. In south-facing slopes, intensive thinning increased air temperature by 2.5 °C and decreased RH by 12 %, resulting in a midday VPD increase of 0.3 kPa. On north-facing slopes, these effects were less pronounced, with air temperature increases of 1.8 °C and RH decreases of 8 %. Thinning effects were amplified in steeper areas and during summer months. Daily cycle analyses revealed that thinning treatments not only increased amplitude but also caused phase shifts in air temperature and RH, particularly in open areas. These findings underscore the importance of integrating local topographic features, thinning-induced microclimatic changes, and the limitations of ERA5 data into adaptive management frameworks.