C04_P01

δ¹³C and intrinsic water use efficiency (iWUE) for trees in various health conditions – case study for Świerklaniec Forest District

Benisiewicz B¹,  Pawełczyk S², Kłusek M³

¹Silesian University Of Technology, Gliwice, Poland, ²Silesian University Of Technology, Gliwice, Poland, ³Silesian University Of Technology, Gliwice, Poland

The research was carried out for two pines growing side by side in the Świerklaniec Forest District. One tree was in good health condition, the other pine had damaged crown and was destined to be cut down. Tree cores were subjected to dendrochronological analysis. Based on these studies, cores were divided into annual increments and subjected to chemical preparation. Carbon isotopic composition of α-cellulose samples was determined using mass spectrometer coupled to the elemental analyzer. Additionally, based on the δ¹³C  values, the iWUE values were calculated, and trees sensitivity to change of  temperature and sum of precipitation was checked.  Isotopic studies covered the years 1967-2020.

               Until the end of the 1990s, the record of  δ¹³C had significantly lower values for a healthy tree than for a damaged tree. The isotope record of a healthy tree since 1980 is characterized by a horizontal trend, in the case of a damaged tree there is a clear downward trend from 1985 to 2000. Correlation coefficients between isotopic and climatic data indicate different sensitivity of trees to climatic factors. Apart from climatic factors, pollutant emissions could have had an impact on tree growth and δ¹³C values, especially since there is a zinc smelter near the sampling site. The characteristics of the trend can be justified by the number of pollutants emitted by industrial plants (especially SO₂), which were the highest in the 1970s and 1980s, and significantly decreased in the 1990s. Differences in iWUE, calculated from data sets, representing two trees are signifficant.