Pre-commercial thinning has potential to mitigate the effect of drought stress on growth but likely removes protection from environmental temperature extremes. Processes driving growth after density management are poorly understood but important when applying thinning to stands that will grow under future warmer and drier conditions. Consequently, we evaluated microclimate and resource availability in operational scale pre-commercial thinning trials (treated and control) of young (19-year-old) boreal trembling aspen/white spruce mixedwoods in northern Alberta, Canada. Thinned stands in this study experienced more temperature extremes, both 30 degrees C, than unthinned stands as well as the same quantity of extreme low soil moisture values. However, lower tree density in thinned stands provided more available heat and higher average soil moisture, especially during dry periods in the year. Soil nutrient supply rates were not different between treatments, nor was soil moisture during wet periods, nor was soil temperature in the early and late parts of the growing season. Regeneration of broadleaf trees species in thinned stands was substantial. Overall, pre-commercial thinning caused both positive and negative changes to the tree-growing environment.

Intensive forest management has promoted an increase in deer (Cervidae) population density. Various silvicultural activities, such as pre-commercial thinning, can change the feeding conditions for deer species, therefore impacting browsing pressure on target tree species. In this study, we analyzed how several factors, including the density of the main tree species, admixture, undergrowth, and forest type, affect deer damage intensity in pine stands, considering deer densities and regional aspects in hemiboreal Latvia. GLMM analysis, based on data from 1238 sample plots, showed that the probability of browsing damage decreases with an increase in the density of undergrowth in young (<20 years) pine stands with a dominant height below 3 m. Also, the probability of pines being damaged by deer was significantly (p = 0.001) higher in stands with fresh pre-commercial thinning than in those with no thinning. However, differences in deer density between regions also determined browsing pressure. Results indicated that undergrowth density, pre-commercial thinning, and deer density may be important drivers of damage levels, especially in the winter browsing of young pine stands on wet mineral soils. Therefore, future research should continue to evaluate applied forest management strategies in hemiboreal forests that provide additional natural food base in the form of woody plants and shrubs in winter forage to ensure more deer-adapted practices.