Linking the response of tree growth to global warming is a key to fully appreciating the impact of climate change on forests. To examine the impacts of temperature and precipitation on tree growth, we studied the radial growth of Pinus tabulaeformis along an altitude gradient from 2032 m a.s.l. to 2361 m a.s.l. on the Helan Mountains, which is almost the northwestern limit of P. tabulaeformis distribution in China. The results showed that, radial growth of P. tabulaeformis decreased significantly (P <0.05) at the low altitude (2032 m a.s.l.) and remained almost steady at the middle and high altitude (2200 m a.s.l. and 2361 m a.s.l.) during the past decades, which was attributed to different climate-radial growth relationships at different altitudes. Total precipitation from the previous July to the current June was an important and effective climatic factor for radial growth at all altitudes. Radial growth was negatively correlated with the mean temperature of the current March at the low altitude and was positively and negatively correlated with the mean temperature of the previous October and the current July at the high altitude, respectively. Increasing temperature of the March under the context of global warming was the main reason for growth reduction at the low altitude. Radial growth at the middle and high altitudes didn't suffer from global warming. It was inferred that conifers at low altitudes of the species' dry distribution limit were more vulnerable to global warming. To cope with possible intensified drought in the growing season and growth reduction in the future, thinning and afforestation should be carried out in the forests, especially at low altitudes.
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1 December 2016
Different Responses of the Radial Growth of Conifer Species to Increasing Temperature along Altitude Gradient: Pinus tabulaeformis in the Helan Mountains (Northwestern China)
Han Y.H. Chen,
Polish Journal of Ecology
Vol. 64 • No. 4
Vol. 64 • No. 4