Effect of Forest Edge Cutting on Transpiration Rate in Picea abies (L.) H. Karst.

A field study was conducted to investigate the effect of forest-edge cutting on the transpiration rates of individual Picea abies (L.) H. Karst. trees regarding their susceptibility to bark-beetle Ips typographus (L.) infestation. The study period, spanning from 2019 to 2020, involved two treatment plots (T-p) and two control plots (C-p). Sap-flow sensors working according to the trunk-heat-balance method were set up on selected sample trees from T-p and C-p. Calibration equations were established after a one-year monitoring period between C-p and T-p, followed by 50-meter-long forest edges created at T-p. The changes in the daily sap flow rates were determined as the differences between the measured and predicted values derived from the calibration equations. The results showed that the created forest-edge clearance caused an increase of up to 16% in the sap flow of trees positioned near the new edge. There was a positive correlation between the increase in the sap flow of the trees and the decreased canopy density of the surroundings. The results of this study indicated that forest-edge clearance and forest fragmentation significantly affect the responses of forest-edge trees to new microclimatic conditions.