Interspecific Differences of Stem Diameter Variations in Response to Water Conditions for Six Tree Species in Northeast China

It is important to understand the response of stem diameter variations in dominant tree species to water conditions in Northeast China. The results will provide basic information for scientific predictions of the future development trend of temperate forests in the eastern mountainous area of northeast China. We employed a high-precision dendrometer to continuously monitor the stem radial changes of six dominant tree species in temperate forests in northeast China from 15 April to 24 October in 2021. Precipitation significantly promoted the tree stem diameter increment. The increment of stem diameter in Juglans mandshurica Maxim., Quercus mongolica Fisch. and Betula platyphylla Suk. had a significantly positive correlation with cumulative precipitation. Correlation analysis revealed that the stem radial change (SRC) of six tree species was positively correlated with precipitation (Pre) and relative humidity (RH), and negatively correlated with water vapor pressure deficit (VPD), indicating that the diameter growth of the six tree species was mainly restricted by water conditions. Under drought stress, the stem radial growth rate of the six tree species slowed down, the growth duration decreased and the tree water deficit (TWD) value increased, while there were obvious interspecific differences. Therefore, water conditions limited the stem radial growth of the six tree species, while each tree species had a different response to drought stress.

Automated summary

Understanding the response of stem diameter variations in dominant tree species to water conditions is crucial, as it provides fundamental information for predicting the development of temperate forests in Northeast China. Using a high-precision dendrometer, we continuously monitored the stem radial changes of six dominant tree species from April 15th to October 24th, 2021. Precipitation showed a significant positive correlation with stem diameter increment in Juglans mandshurica Maxim., Quercus mongolica Fisch., and Betula platyphylla Suk. Correlation analysis revealed that the stem radial change of the six tree species was positively correlated with precipitation and relative humidity, while negatively correlated with water vapor pressure deficit, indicating that water conditions primarily limited the diameter growth of these tree species. Under drought stress, the growth rate and duration of stem radial growth decreased, and the tree water deficit value increased, with interspecific variations observed.