Aims: Stem radial increment rate and duration are the most important parameters in determining the width of annual tree rings. Therefore there is a need to identify the contributions of rate and duration to annual radial increments and their relationships with environmental factors. Methods: We analyzed intra-annual stem increments of five Picea meyeri trees in a sub-alpine habitat of North-Central China over 7 years (2008–2015, except for the year 2012) with point dendrometers in this study. Main results and scientific findings: (1) Approximately 53% of the variability in the annual radial increments is attributable to the rate of radial increment and approximately 47% to its duration. (2) Contribution of cessation time to the annual increments was more than three times that of the initiation time. (3) Initiation of radial increment was primarily controlled by soil temperature, and the warmer soil temperature could advance the initiation time. Cessation and rate of radial increment were mainly influenced by thermal and light-related environmental factors. During growing seasons, low temperatures and insufficient light caused by many rainy and cloudy days at the high altitudes of the Luya Mountains may result in earlier cessations and lower rates of radial increment. Application potential: Our results may have further applications in modeling the responses of tree stem growth to climate change in a sub-alpine habitat, such as in North-Central China and the similar sites.
No datasets are available for this submission.