Contribution rate of climate factors to radial growth of main coniferous species in spurce-fir conifer mixed forest of northeastern China

Objective This paper aims to analyze the effects of climate change on radial growth of conifers, reveal the response rules of forests to climate change, and provide theoretical support for the adaptive management of forest ecosystem under the background of global warming.

Method Taking three conifer species in the spurce-fir conifer mixed forest of Jingouling Forest Farm of northeastern China as the research object, the standardized chronology of ring width of three conifer species was established. The correlation between ring width of three species and climate factors was analyzed, so as to clarify the significant climate factors limiting their radial growth in this area and the stability of correlation relationship. The contribution rate of significant climate factors to the change of tree ring width was quantified using the hierarchical partitioning method.

Result Under the 95% confidence interval, the correlation analysis with climatic factors showed that the radial growth of Pinus koraiensis and Abies nephrolepis was affected by both air temperature and precipitation, and was positively correlated with the temperature at the beginning of growing season. The tree-ring width of Picea jezoensis was mainly affected by temperature, the overall correlation with precipitation was weak, and it was negatively correlated with temperature in autumn and winter. The three tree species were affected by the climate factors of previous year to a certain extent. The effect of tree growth was the “lag effect”. The sliding correlation analysis showed that there were differences in the response relationship between three major conifer species and climate factors in the Jingouling Forest Farm in this study, and the negative correlation showed an increasing trend. By quantifying the contribution rate of significant climate factors to the change of tree ring width, it was found that the average temperature in March had the highest contribution rate to Pinus koraiensis (34.56%), the lowest temperature in April had the highest contribution rate to Abies nephrolepis (22.29%), and the lowest temperature in April had the highest contribution rate to Picea jezoensis (60.89%).

Conclusion The hierarchical partitioning analysis can effectively quantify the contribution rate of climate factors to tree ring growth of various species. The analysis results can provide theoretical and data reference for formulating forest management measures in this region in the future.