Pre-commercial thinning in boreal mixedwoods increases temperature extremes without affecting extreme low soil moisture values

Le résumé fourni par la source

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 <0°C and >30°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.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.