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Response of radial growth of P. sylvestris var. mongolica (P. sylvestris) and Larix gmelinii (Rupr.) Kuzen (L. gmelinii) to extreme climate and their future growth trends in the Daxing’anling Mountains, northeast China

Abudoureheman Ruxianguli Man, Zhang Tongwen, Yu Shulong, Zhang Ruibo, Shang Huaming, Liu Kexiang, Gou Xiaoxia, Guo Dong, Yuan Yujiang

Geochronometria

2024

Vol. 51, no. 1

1--16

The Daxing’anling Mountains are vulnerable to extreme weather and ecological degradation. Forests in this region have been substantially affected by extreme events; however, the pattern of future forest change remains uncertain. To determine the trends and reasons for extreme climate change, reanalysis data were used to assess the potential forest degradation resulting from future extreme climate events. Using tree-ring width chronologies of Pinus sylvestris var. mongolica (1952-2015) and Larix gmelinii (Rupr.) Kuzen (1962-2015), we performed a comparative analysis of the relationships between radial growth of these two tree species and extreme indices based on Pearson correlations. The functions between extreme climate and tree ring width were then used in the LASSO algorithm. Using the CMIP6 models under the intermediate emission scenario (SSP2-4.5), we projected the tree ring width of the two species from 2015 to 2100 using calibrated meteorological fields. The tree-ring chronologies of both species were correlated negatively with extreme warm temperature indices and positively with extreme precipitation indices. P. sylvestris responded more significantly to extremely high temperature indices and precipitation, with a certain lag effect. L. gmelinii responded significantly to extremely cold temperature indices. Tree species specificity may explain why the two species show different growth–climate relationships. The growth of P. sylvestris may decrease during extreme climate change conditions, whereas the effect on L. gmelinii future growth is not significant. The predicted growth series in the 2015–2100 period showed that three abnormally high values, six abnormally low values, and one extreme abnormally low value occurred in P. sylvestris, whereas there were two extreme abnormally low values, four abnormally low values, and four abnormally high values in L. gmelinii. Our findings can help predict the resilience and sustainability of forest ecosystems in the face of extreme climate change and contribute to forest management strategies.

Responses to Climate Factors in the Radial Growth of Schrenk Spruce (Picea Schrenkiana) in the Yili Region, Northwest China

Liu Kexiang, Zhang Tongwen, Zhang Ruibo, Qin Li, Yu Shulong, Jiang Shengxia, Fan Yuting

Geochronometria

2023

Vol. 50, no. 1

195--205

To examine the associations existing between elevation and tree growth, tree-ring width chronologies of Schrenk spruce (Picea schrenkiana) were developed from sampling sites at different elevations in the Wusun Mountain, Yili region, Xinjiang, northwest China. The radial growth of high-elevation trees was observed to be primarily influenced by meteorological factors in the non-growth season of the previous year. The radial growth of mid-elevation trees was mainly affected by temperature. The radial growth of low-elevation trees was mainly affected by both temperature and relative humidity. About climate change, the radial growth of Schrenk spruce at different elevations showed a non-uniform response to climate variables. Under the condition of intensified drought stress in the future, the forest ecosystem is likely to be greatly affected, and the radial growth of Schrenk spruce at low elevations will be especially inhibited.