Snowfall during winter is decreasing and the period of snow cover shortening with climate change affecting the coupling between soil and air temperature and humidity. Snow cover isolates the ground and decreases the soil frost. Lack of snow cover may lead to deeper soil frost, and soil can remain frozen after the start of growing season, which prevents the water and nutrient uptake of trees. Alessandro Zanetti studies in his PhD how decreasing snow cover affects trees. Massive skeletons for snow shelters have been built in Hyytiälä Research Station for the purpose this autumn. Just before the winter, we aim to cover the area with snow shelters to study how e.g. soil temperature, root growth, root respiration and tree water usage is affected by decreasing snow cover. Many people have been helping us in the field (special thanks to the main shelter architect Juho Aalto and root expert Kira Ryhti), and we look forward to see the first results next spring. The work is part of Anna Lintunen’s University of Helsinki funded 3 year’s research project on the Effects of wintertime physiology of trees on forest carbon sequestration in changing climate.