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Different responses of the radial growth of conifer species to increasing temperature along altitude gradient: Pinus tabulaeformis in the Helan Mountains (Northwestern China)

100%

Zhang L., Jiang Y., Zhao S., Dong M., Chen H. Y. H., Kang X.

Polish Journal of Ecology

2016

tom 64

nr 4

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.

Intra-versus inter-population variation of cone and seed morphological traits of Pinus tabulaeformis Carr. in Northern China: impact of climate-related conditions

80%

Ji M., Zhang X., Wang Z., Zhang Q., Deng J.

Polish Journal of Ecology

2011

tom 59

nr 4

Morphological traits of conifer species are known to vary adaptively with the geographic and climatic variables, but little is known about intra- and inter-population variation and impact of associated climate factors on the morphological variation. Chinese hard pine (Pinus tabulaeformis Carr) is a major and widespread component of coniferous forests in the temperate and semi-humid zone in northern China. Here we investigated 12 life history traits involving cone length (CL), width (CW) and dry weight (CDW), cone length to width ratio (CLW ), seed length (SL ), width (CW) and total weight (STW ), seed length to width ratio (SLW ), seed wing length (SWL), width (SWW) and total weight (SWTW ), seed wing length to width ration (SWLW ) at 12 sites between longitudes (102oE to 122oE) and latitudes (32oN to 43oN) covering an altitude range of 125–2581 m. Our results showed that each morphological character presented a large variation both within and among populations. Moreover, we found that proportion of phenotypic variation (i.e. Vst, %) of the all cone traits except for the cone width was over 50% among populations, indicating that the variation of these traits was mainly controlled by the environmental variables. Although the mean proportion of phenotypic variation of all measured traits was only about 28% among populations of this species, it was much higher than those of other conifers, which further suggested that this species held the higher adaptive phenotypic variation or stress-tolerance ability under varying environmental conditions. Furthermore, the phenotypic variation presented a general pattern that almost all measured traits were negatively correlated with the potential evapotranspiration which reflected the synthetic effects of multiple factors such as the temperature and rainfall, rather than a single environmental or climatic factor. In conclusion, according to the relationship between phenotypic variation and climate factors, it will undoubtedly provide important information for the reforestation and genetic conservation for this species in the changing climate.

Ograniczanie wyników

2 Polish Journal of Ecology

1 Chen H. Y. H.

1 Deng J.

1 Dong M.

1 Ji M.

1 Jiang Y.

1 Kang X.

1 Wang Z.

1 Zhang L.

1 Zhang Q.

1 Zhang X.

1 Zhao S.

1 2016

1 2011

Wyniki wyszukiwania

Different responses of the radial growth of conifer species to increasing temperature along altitude gradient: Pinus tabulaeformis in the Helan Mountains (Northwestern China)

Intra-versus inter-population variation of cone and seed morphological traits of Pinus tabulaeformis Carr. in Northern China: impact of climate-related conditions