Search Results (2)

Global warming is critical to the distribution pattern of endangered plants; therefore, understanding the future changes in the adaptive areas of endangered spruce and driving factors on the Tibetan Plateau is of great research significance for spruce species conservation and sustainability. In this study, variations in the distribution pattern of four endangered spruce species (Picea. Balfouriana, Picea. Linzhiensis, Picea. Complanata, and Picea. Aurantiaca) on the Tibetan Plateau were predicted by the MaxEnt model, and the important environmental variables affecting its geographic distribution were analyzed. We found that under the current climate conditions, the four endangered spruce species were mainly situated in the southern and southeastern Tibetan Plateau. The mean temperature of the coldest quarter was a key environmental variable affecting the geographic distribution of four endangered spruce species, with suitable growth ranges of −9–8 °C for P. balfouriana and −6–5 °C for P. linzhiensis, P. complanata, and P. aurantiaca. Under different future climate pathways, the highly suitable habitat of four endangered spruce was mainly situated in the east, south, and southeast districts of the Tibetan Plateau. With the suitable growth range of key variables continuing to expand on the Tibetan Plateau, the area of suitable habitat for each of the four endangered spruce species increases to varying degrees. Compared with the current climate, four endangered spruce species will expand to the northwest of the Tibetan Plateau under different future climate scenarios, and the degree of expansion will increase with the increase in temperature. This study not only reveals the response of suitable habitats of four endangered spruce species to global warming, but also provides scientific insights for spruce population conservation and sustainable development. Full article

Tree-rings are recorders of environmental signals and are therefore often used to reconstruct past environmental conditions. In this paper, we present four annually resolved, multi-centennial tree-ring isotope series from the southeastern Tibetan plateau. The investigation site, where juniper and spruce trees jointly occur, is one of the highest known tree-stands in the world. Tree ring cellulose oxygen (δ¹⁸O) and carbon (δ¹³C) isotopes were analyzed for a common period of 1685–2007 AD to investigate climate–isotope relationships. Therefore, various climate parameters from a local meteorological station and from the CRU 4.02 dataset were used. Tree-ring δ¹⁸O of both species revealed highly significant sensitivities with a high degree of coherence to hydroclimate variables during the growing season. The obtained δ¹⁸O–climate relationships can even be retained using a species mean. In contrast, the individual δ¹³C series indicated a weaker and non-uniform response to the tested variables. Underlying species-specific responses and adaptations to the long-term trend in atmospheric CO₂ bias even after a trend correction identified dominant environmental factors triggering the tree-ring δ¹³C at our site. However, analysis of individual intrinsic water-use efficiency in juniper and spruce trees indicated a species-specific adaptation strategy to climate change. Full article