Tree-soil-water relationships in European black alder forest – case study

Environmental factors, including temperature and air humidity, undoubtedly affect the life processes of plants, but in the black alder an additional factor responsible for the tree activity is the seasonal variability of soil moisture. In the conducted research, the activity of the tree, expressed as the conductivity measured in Hz, was seven times lower, in the period when the water level in 2018 was high, than in the analogous period in 2019, when the level of groundwater was low. In the period from January 1 to May 31, 2018, the maximum value of conductivity reached 601 Hz, while in the analogous period of 2019, 4229 Hz. Differences in the soil moisture also affected the length of the dormancy period of the tree, which in the first observation season lasted from November 2017 to April 2018, while at the turn of 2018 and 2019, the tree activity stopped for just a few days when air temperature dropped on January 23, 2019 to -9.8 oC.